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1. Ai, Yuejie
Li, Xin
KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
Ji, Yongfei
Song, Wei-Guo
Luo, Yi
Hydrophobicity and Hydrophilicity Balance Determines Shape Selectivity of Suzuki Coupling Reactions Inside Pd@meso-SiO2 Nanoreactor2016In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, no 19, p. 10244-10251Article in journal (Refereed)
Molecular sorting and catalysis directed by shape selectivity have been extensively applied in porous extended frameworks for a low-carbon, predictable, renewable component of modern industry. A comprehensive understanding of the underlying recognition mechanism toward different shapes is unfortunately still missing, owing to the lack of structural and dynamic information under operating conditions. We demonstrate here that such difficulties can be overcome by state-of-the-art molecular dynamics simulations which provide atomistic details that are not accessible experimentally, as exemplified by our interpretation for the experimentally observed aggregation induced shape selectivity for Suzuki C-C coupling reaction catalyzed by Pd particles in mesoporous silica. It is found that both aggregation ability and aggregating pattern of the reactants play the decisive role in controlling the shape selectivity, which are in turn determined by the balance between the hydrophobicity and hydrophilicity of the reactants, or in other words, by the balance between the noncovalent hydrogen bonding interaction and van der Waals forces. A general rule that allows prediction of the shape selectivity of a reactant has been proposed and verified against experiments. We show that molecular modeling is a powerful tool for rational design of new mesoporous systems and for the control of catalytic reactions that are important for the petrochemical industry.
2. Bai, Linyi
Zhu, Liangliang
Ang, Chung Yen
Wu, Shaojue
Zeng, Yongfei
Ågren, Hans
Zhao, Yanli
Iron( III)-Quantity-Dependent Aggregation-Dispersion Conversion of Functionalized Gold Nanoparticles2014In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 14, p. 4032-4037Article in journal (Refereed)
Developing gold nanoparticles (AuNPs) with well-designed functionality is highly desirable for boosting the performance and versatility of inorganic-organic hybrid materials. In an attempt to achieve ion recognition with specific signal expressions, we present here 4-piperazinyl-1,8-naphthalimide-functionalized AuNPs for the realization of quantitative recognition of Fe-III ions with dual (colorimetric and fluorescent) output. The research takes advantage of 1)quantity-controlled chelation-mode transformation of the piperazinyl moiety on the AuNPs towards Fe-III, thereby resulting in an aggregation-dispersion conversion of the AuNPs in solution, and 2)photoinduced electron transfer of a naphthaimide fluorophore on the AuNPs, thus leading to reversible absorption and emission changes. The functional AuNPs are also responsive to pH variations. This strategy for realizing the aggregation-dispersion conversion of AuNPs with returnable signal output might exhibit application potential for advanced nanoscale chemosensors.
3. Bu, L.
Chen, J.
Wei, X.
Xie, Y.
An AIE and ICT based NIR florescent probe for cysteine and homocysteine2017In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 136, p. 724-731Article in journal (Refereed)
A combination of aggregation-induced emission and intramolecular charge transfer was achieved by using a triphenylamine analogue and a dicyanovinyl moiety as the electron donating and accepting units, respectively. Hence, we designed and synthesized a probe with a D-π-A framework as a near-infrared fluorescence turn-on probe for biothiols (cysteine and homocysteine). Owing to the remarkable intramolecular charge transfer effect as well as intramolecular rotations associated with the donor moiety, the probe exhibits extremely weak fluorescence, which becomes a good starting point for developing fluorescence "turn-on" probes. Upon reaction with cysteine or homocysteine utilizing the dicyanovinyl moiety, the intramolecular charge transfer character was weakened, and the reacting products were observed to aggregate in aqueous solutions, resulting in the aggregation-induced emission effect with red fluorescence at 651 and 656 nm, respectively. Hence, the probe could be used as a fluorescence "turn-on" sensor for cysteine and homocysteine, with the sensing time of less than 4 min and the detection limits of 8.4 μM and 5.7 μM towards cysteine and homocysteine, respectively. The probe could distinguish cysteine and homocysteine from glutathione. The sensing mechanism was systematically investigated by employing high resolution mass spectrometry, 1H NMR and density functional theory calculations as well as checking the solvent viscosity dependent fluorescence, and thus the nucleophilic addition products, the intramolecular charge transfer character, and the aggregation-induced emission behaviour were clearly elucidated. It is noteworthy that the low cytotoxicity, the intrinsic aggregation-induced emission nature and near-infrared emissions enable the application of the probe in living cell imaging. © 2016 Elsevier Ltd
4. Cai, Shengyun
Hu, Xiaohao
Tian, Guojian
Zhou, Haitao
Chen, Wei
Huang, Jinhai
Su, Jianhua
Photo-stable substituted dihydroindolo[2,3-b]carbazole-based organic dyes: tuning the photovoltaic properties by optimizing the pi structure for panchromatic DSSCs2014In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 70, no 43, p. 8122-8128Article in journal (Refereed)
Three dihydroindolo[2,3-b]carbazole (DDC) donor based organic dyes (DDC6-DDC8) with long conjugated systems were successfully synthesized and characterized by optical, electrochemical, computational analysis, and photovoltaic methods. It was found that the elongated pi system as well as the high molar extinction coefficients (4.2-5.3 M-1 cm(-1)) sufficiently reinforced the light harvesting ability with the IPCE response of one dye DDC8 extended to 850 nm, which resulted in large J(sc) of these dyes based devices (high as 16.41 mA cm(-2)). The attached alkyl chains suppress the dark current to some extent, resulting the DDC6 and DDC7 devices in high V-oc, while DDC8 displayed low V-oc, because BTD in DDC8 could attract the iodine ion, which could accelerate the charge recombination. Among the three dyes, DDC7 displayed the best performance with an eta value 6.53% under 4 mu m thick scattering layer (condition 1+1), which was boosted to 7.49% under 8 mu m thick scattering layer (condition 1+2). The photo-stability measurements indicated that all the three dyes are fairly photo-stable.
5. Chen, Bin
Ding, Yubin
Zhu, Weihong
Hill, Jonathan P.
Ariga, Katsuhiko
Xie, Yongshu
Steric hindrance-enforced distortion as a general strategy for the design of fluorescence "turn-on" cyanide probes2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 86, p. 10136-10138Article in journal (Refereed)
For the rational design of fluorescence "turn-on" cyanide probes, a general strategy is developed by introducing a dicyanovinyl group at the sterically demanding position of a large pi framework.
Sun, Xi
TICT based fluorescence "turn-on" hydrazine probes2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 199, p. 93-100Article in journal (Refereed)
Fluorescence "turn-on" probes PC3 and C3 with weak background emissions were developed for hydrazine sensing. The aldehyde and dicyanovinyl groups were used as the recognition units for PD and C3, respectively. Because of low reactivity of the aldehyde group, the fluorescence of PC3 was enhanced by only ca. 93 folds upon addition of a large amount of 1646 eq. hydrazine. In contrast, 0 exhibited fluorescence enhancement by ca. 239 folds upon addition of only 1.3 eq. hydrazine, and thus it showed high sensitivity towards hydrazine, with the detection limit of 7 ppb. In aqueous systems, it also works well with improved selectivity for hydrazine over CN-. The weak fluorescence of PC3 and 0 can be ascribed to twisted intramolecular charge transfer (TICT) processes by the combination of the bulky diphenylamino and 9-anthryl units, which were well demonstrated by theoretical calculations, viscosity dependent fluorescence, and fluorescence decay behaviour. Addition of hydrazine induced the disappearance of the TICT deactivation pathway, resulting in the observed fluorescence enhancement. It can be concluded that the combination of the bulky diphenylamino and 9-anthryl units is an effective approach for developing fluorescence turn-on hydrazine probes based on the TICT mechanism.
Yu, Gang
Wang, Cheng
Liu, Zhiwei
Full-colour luminescent compounds based on anthracene and 2,2 '-dipyridylamine2013In: Journal of Materials Chemistry C, ISSN 2050-7526, Vol. 1, no 44, p. 7409-7417Article in journal (Refereed)
Starting from two simple units of anthracene and 2,2'-dipyridylamine, a series of new luminescent compounds 1-8 were designed and synthesized by a combined strategy of changing the connection mode between the two units, extending the conjugation size, and introducing an additional electron donor. Photophysical properties of 1-8 were investigated and discussed on the basis of solvatochromic behaviour, theoretical calculations, crystal structure, and optimized structures. Interestingly, the emission wavelengths of these compounds could be successfully tuned from violet to red both in solutions and the solid-state, and prominent positive solvatochromism was observed for the compounds with a D-p-A framework. Consider compound 7 as an example, it shows peaks at 526 nm and 627 nm in cyclohexane and DMSO, respectively. Meanwhile, the quantum yield was decreased from 0.80 in cyclohexane to 0.12 in DMSO. The introduction of bulky groups was demonstrated to be effective for suppressing the aggregation effect and thus improving the solid state emission quantum yield. These results indicate that the combined structure modulation strategy offers a powerful tool for tuning the emission behaviour. To demonstrate the possibility of practical applications, 2 was employed as the emitting material for the fabrication of deep-blue organic light-emitting diodes (OLEDs), which showed a maximum external quantum efficiency of 2.2%. The CIE coordinates of (0.15, 0.08) are indicative of excellent blue color purity.
8. Chen, Long
Ying, Weijiang
Zhang, Xiaoyu
Guo, Fuling
Li, Jing
Hua, Jianli
5,6-Bis(octyloxy)benzo[c][1,2,5]thiadiazole-Bridged Dyes for Dye-Sensitized Solar Cells with High Open-Circuit Voltage Performance2013In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 9, p. 1770-1780Article in journal (Refereed)
Three new metal-free dyes with a 5,6-bis(octyloxy) benzo[c][1,2,5] thiadiazole core (DOBT-I-III) have been designed and synthesized for use as DSSCs. Their absorption properties and electrochemical and photovoltaic performances have been investigated systematically. The DSSCs based on DOBT-I-III show high open-circuit voltages (V-oc) of 829, 818, and 784 mV, respectively. Of the three dyes, DOBT-III, which contains a thiophene-bridging linker, exhibits the best photovoltaic performance: a short-circuit photocurrent density (J(sc)) of 12.74 mA cm(-2) and a fill factor (FF) of 0.73, which corresponds to an overall conversion efficiency of 7.29% under standard global AM 1.5 solar conditions.
9. Chen, S.
Li, W.
Zhu, W. -H
Aggregation-controlled photochromism based on a dithienylethene derivative with aggregation-induced emission2017In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 5, no 10, p. 2717-2722Article in journal (Refereed)
We report novel aggregation-induced emission (AIE) characteristics involving aggregation-controlled photochromism properties of a dithienylethene derivative, BTE-EQ, where two quinolinemalononitrile (EQ) units are covalently attached to a dithienylethene core. The typical AIE effect of BTE-EQ has been found to originate from the AIE character of the EQ units with respect to the reference compound BTE, which does not contain an EQ unit. The photochromism study, together with density functional theory calculations, reveals that the photochromic activity of BTE-EQ can be reversibly switched off and on by controlling the aggregation state during the AIE process, which provides a novel route to controlling the photochromism of diarylethenes.
10. Chen, Shangjun
Li, Wenlong
Zhu, Wei-Hong
Substitution effect on the photochromic properties of benzo[b]thiophene-1,1-dioxide based diarylethenes2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 106, p. 87626-87634Article in journal (Refereed)
Benzo[b]thiophene-1,1-dioxide based diarylethenes (DAEs), BTT-1 to BTT-4, containing methyl, phenyl, formyl and triphenylamine groups at the 5,5'-position of the thiophene rings have been developed for gaining an insight into the substituent effect on the absorption and photochromic properties. Electron-donating substituents, such as phenyl and triphenylamine groups, are found to be effective at shifting the absorption band to a longer wavelength and decreasing the cyclization quantum yield. The electron-withdrawing formyl group can increase the cyclization quantum yield, but it reduces the thermal stability of the ring-closed isomer to some extent. BTT-4 bearing a triphenylamine group shows the poorest fatigue resistance among these four compounds, which is possibly due to the larger extended pi-conjugation length in the ring-closed isomer. BTT-2 bearing a phenyl unit undergoes typical photochromic reaction not only in solution, but also in PMMA thin film and in bulky crystals with excellent fatigue resistance and thermal stability.
11. Chen, Wei
Zhang, Zhiyun
Highly sensitive detection of low-level water content in organic solvents and cyanide in aqueous media using novel solvatochromic AIEE fluorophores2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 16, p. 12191-12201Article in journal (Refereed)
A great deal of effort has been devoted to develop easy-to-use fluorescent probes for detecting analytes due to their advantages in the field of chemo- and bio-sensing. Herein, two novel 2,2 '-biindenyl-based derivatives BDM and BDBM containing dicyanovinyl groups have been designed and synthesized, and are shown to possess the remarkable dual properties of solvatochromism and aggregation-induced emission enhancement (AIEE). Importantly, both of them are found to serve as fluorescent indicators for the qualitative and quantitative detection of low-level water in organic solvents. Meanwhile, both BDM and BDBM emit yellowish orange and orange fluorescence, respectively, in their aggregated states. Furthermore, with dicyanovinyl groups as the recognition sites, both compounds can act as colourimetric and fluorescent sensors for highly sensitive and selective detection of cyanide in aqueous media, and the apparent response signals can be observed by the naked eye even in the presence of various interference anions, promising practical applications for detecting cyanide in drinking water. Besides, optical spectroscopic techniques, NMR titration measurements, and density functional theory calculations are conducted to rationalize the sensing mechanisms of the two probes.
12. Chen, X.
Zhu, L.
Wang, D.
Zou, Q.
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
Chen, W.
A unimolecular platform based on diarylethene with multiple stimuli-gated photochromism2019In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 164, p. 91-96Article in journal (Refereed)
The gated photochromic systems have attracted great interest in scientific researches due to their merits in the opto-electronic fields, whereas the multi-stimuli gating function in a unimolecular platform has rarely been addressed. Herein, a new strategy to realize multi-stimuli gated photochromic function was devised relying on a simple Schiff-based diarylethene derivative. The compound shows no photoswitching properties in solution under irradiation with any wavelength of light. It is noteworthy that mecury(II) ions, water and protons can trigger its photo-reactivity independently with different absorption changes, respectively. Therefore, a molecular logic circuit with four inputs, including mecury(II) ions, water, protons and UV light, was fabricated on the basis of the unimolecular platform, suggesting promise for application in multi-controlled photoswitchings. These results could be valuable for the further development of photoswitchings with multiple stimuli responses.
13. Ding, Li
Highly sensitive determination of low-level water content in organic solvents using novel solvatochromic dyes based on thioxanthone2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 66, p. 7319-7321Article in journal (Refereed)
Two thioxanthone-based fluorescent probes exhibited prominent solvatofluorochromism, and they were further found to be useful as fluorescence indicators for the qualitative and quantitative detection of low-level water content in various solvent media.
14. Ding, Yubin
Li, Tong
From nonconjugation to conjugation: novel meso-OH substituted dipyrromethanes as fluorescence turn-on Zn2+ probes2013In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 11, no 16, p. 2685-2692Article in journal (Refereed)
Most reported Zn2+ probes suffer from the interference of background fluorescence originated from the conjugated structures of commonly utilized fluorophores. In this work, three novel meso-hydroxyl group substituted dipyrromethanes DPMOH1-DPMOH3 were synthesized and found to be colourless and nonfluorescent due to the interruption of the conjugated p system by an sp(3) carbon between the two pyrrolic units. Interestingly, only the addition of Zn2+ to the solutions of DPMOH1-DPMOH3 promoted their oxidation to dipyrrin forms, and bright fluorescence "turn on" was observed due to the formation of corresponding dipyrrin complexes with the dipyrrin : zinc stoichiometry of 2 :1. Zn2+ detection mechanism was investigated by UV-Vis, fluorescence, H-1 NMR and HRMS analyses, which can be ascribed to the CHEF type fluorescence enhancement, resulting from good rigidity of the dipyrrin complexes. Hence, DPMOH1-DPMOH3 can be used as fluorescence turn-on Zn2+ probes with the advantage of no background fluorescence.
Andreasson, Joakim
Tian, He
Acid/Base Switching of the Tautomerism and Conformation of a Dioxoporphyrin for Integrated Binary Subtraction2014In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 40, p. 12910-12916Article in journal (Refereed)
Compared with most of the reported logic devices based on the supramolecular approach, systems based on individual molecules can avoid challenging construction requirements. Herein, a novel dioxoporphyrin DPH22 was synthesized and two of its tautomers were characterized by single-crystal X-ray diffraction studies. Compound DPH22 exhibits multichannel controllable stepwise tautomerization, protonation, and deprotonation processes through interactions with H and F- ions. By using the addition of H+ and F- ions as inputs and UVNis absorption values at.1=412, 510, 562, and 603 nm as outputs, the controlled tautomerism of DPH22 has been successfully used for the construction of an integrated molecular level half-subtractor and comparator. In addition, this acid/base-switched tautomerism is reversible, thus endowing the system with ease of reset and recycling; consequently, there is no need to modulate complicated intermolecular interactions and electron-/chargetransfer processes.
alpha-Monoacylated and alpha,alpha '- and alpha,beta '-Diacylated Dipyrrins as Highly Sensitive Fluorescence "Turn-on" Zn2+ Probes2013In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 78, no 11, p. 5328-5338Article in journal (Refereed)
With the purpose of developing readily synthesized CHEF (chelation-enhanced fluorescence) type Zn2+ probes with relatively simple molecular structures and excellent sensing behavior, p-anisoyl chloride was used for the acylation of 5-(pentafluorophenyl)dipyrromethane. Interestingly, the alpha,beta'-diacylated product PS2 with a unique substitution mode was obtained in high yield in addition to the normal a-substituted mono- and diacylated products PSI and PS3. Further oxidation of PS1-PS3 afforded dipyrrins S1-S3. Crystal structure and H-1 NMR measurements of S2 demonstrate the existence of a pure tautomer, which is consistent with DFT calculations. S1-S3 show highly Zn2+ selective "turn-on" fluorescence based on a CHEF mechanism by the formation of 2:1 (probe:metal) Zn2+ complexes. The emission colors can be easily tuned from green to red by changing the dipyrrin substitution modes. Furthermore, these probes demonstrate fast responses and wide applicable pH ranges. Among them, S2 shows the highest Zn2+ sensitivity, with a detection limit of 4.4 x 10(-8) M.
17. Hede, T.
Leck, C.
Tu, Yaoquan
Model HULIS compounds in nanoaerosol clusters: investigations of surface tension and aggregate formation using molecular dynamics simulations2011In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 11, no 13, p. 6549-6557 Article in journal (Refereed)
Cloud condensation nuclei act as cores for water vapour condensation, and their composition and chemical properties may enhance or depress the ability for droplet growth. In this study we use molecular dynamics simulations to show that model humic-like substances (HULIS) in systems containing 10 000 water molecules mimic experimental data well referring to reduction of surface tension. The model HULIS compounds investigated in this study are cis-pinonic acid (CPA), pinic acid (PAD) and pinonaldehyde (PAL). The structural properties examined show the ability for the model HULIS compounds to aggregate inside the nanoaerosol clusters.
18. Hede, Thomas
KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
Leck, Caroline
HULIS in Nanoaerosol Clusters; Investigations of Surface Tension and Aggregate Formation using Molecular Dynamics Simulations2011In: Atmospheric Chemistry and Physics Discussions, ISSN 1680-7367, E-ISSN 1680-7375 Article in journal (Other academic)
Cloud condensation nuclei act as cores for water vapor condensation, and their composition and chemical properties may enhance or depress the ability for droplet growth. In this study we use molecular dynamics simulations to show that humic-like substances of larger systems (8.6 nm in diameter) mimic experimental data well referring to reduction of surface tension. The structural properties examined show the ability for the humic-like substances to aggregate inside the nanoaerosol clusters.
19. Hong, Tao
Song, Heli
Zhang, Weibing
Syntheses of mono- and diacylated bipyrroles with rich substitution modes and development of a prodigiosin derivative as a fluorescent Zn(II) probe2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 12, p. 6133-6140Article in journal (Refereed)
The acylation of 2,20-bipyrrole with pentafluorobenzoyl chloride in the presence of AlCl3 afforded six acylated products with rich alpha-, beta-, beta(1)-, alpha,alpha'-, alpha,beta(')-, and alpha,beta(1)'-substitution modes for 1-6, respectively. Then, the alpha,alpha'-diacylated compound 4 was used to synthesize a prodigiosin derivative 9, which provides an alternative method for the syntheses of prodigiosin derivatives. Crystal structures of 1, 4 and 9 show interesting supramolecular dimers formed by multiple hydrogen bonds, O...pi interactions, as well as pi... pi interactions. Interestingly, 9 shows fluorescence turn-on probing behavior towards Zn2+ both in DMF and in DMF-HEPES, with high sensitivity and selectivity. The detection limit for Zn2+ in DMF was calculated to be 1.1 x 10(-8) M.
Hua, Weijie
Tian, Guangjun
Fronzoni, Giovanna
Stener, Mauro
Fe L-Edge X-ray Absorption Spectra of Fe(II) Polypyridyl Spin Crossover Complexes from Time-Dependent Density Functional Theory2013In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 117, no 51, p. 14075-14085Article in journal (Refereed)
L-edge near-edge X-ray fine structure spectroscopy (NEXAFS) has become a powerful tool to study the electronic structure and dynamics of metallo-organic and biological compounds in solution. Here, we present a series of density functional theory calculations of Fe L-edge NEXAFS for spin crossover (SCO) complexes within the time-dependent framework. Several key factors that control the L-edge excitations have been carefully examined using an Fe(II) polypyridyl complex [Fe(tren(py)(3))](2+) (where tren(py)(3) = tris(2-pyridylmethyliminoethyl)amine) as a model system. It is found that the electronic spectra of the low-spin (LS, singlet), intermediate-spin (IS, triplet), and high-spin (HS, quintet) states have distinct profiles. The relative energy positions, but not the spectral profiles, of different spin states are sensitive to the choice of the functionals. The inclusion of the vibronic coupling leads to almost no visible change in the resulting NEXAFS spectra because it is governed only by low-frequency modes of less than 500 cm(-1). With the help of the molecular dynamics sampling in acetonitrile at 300 K, our calculations reveal that the thermal motion can lead to a noticeable broadening of the spectra. The main peak position is strongly associated with the length of the Fe-N bond.
21. Jana, Avijit
Bai, Linyi
Morphology Tuning of Self-Assembled Perylene. Monoimide from Nanoparticles to Colloidosomes with Enhanced Excimeric NIR Emission for Bioimaging2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 3, p. 2336-2347Article in journal (Refereed)
Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.
Nguyen, Kim Truc
Zhu, Pengcheng
Tan, Nguan Soon
Perylene-Derived Single-Component Organic Nanoparticles with Tunable Emission: Efficient Anticancer Drug Carriers with Real-Time Monitoring of Drug Release2014In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 8, no 6, p. 5939-5952Article in journal (Refereed)
An organic nanoparticle-based drug delivery system with high drug loading efficacy (similar to 79 wt %) was developed using a perylene-derived photoremovable protecting group, namely, perylene-3,4,9,10-tetrayltetramethanol (Pe(OH)(4)). The anticancer drug chlorambucil was protected by coupling with Pe(OH)(4) to form photocaged nanoparticles (Pe(OH)(4)). The photorelease mechanism of chlorambucil from the Pe(Cbl)(4) conjugate was investigated experimentally by high-resolution mass spectrometry and theoretically by density functional theory calculations. The Pe(Cbl)(4) nanoparticles perform four important roles: (i) a nanocarrier for drug delivery, (ii) a phototrigger for drug release, (iii) a fluorescent chromophore for cell imaging, and (iv) a photoswitchable fluorophore for real-time monitoring of drug release. Tunable emission of the perylene-derived nanoparticles was demonstrated by comparing the emission properties of the Pe(OH)(4) and Pe(Cbl)(4) nanoparticles with perylene-3-ylmethanol. These nanoparticles were subsequently employed in cell imaging for investigating their intracellular localization. Furthermore, the in vivo toxicity of the Pe(OH)(4) nanoparticles was investigated using the mouse model. Histological tissue analysis of five major organs, i.e., heart, kidney, spleen, liver, and lung, indicates that the nanoparticles did not show any obvious damage to these major organs under the experimental conditions. The current research presents a successful example of integrating multiple functions into single-component organic nanoparticles for drug delivery.
23. Jiang, Tao
Li, Dongyu
Hang, Yandi
Gao, Yuting
Zhang, Hequn
Zhao, Xinyuan
Li, Bo
Qian, Jun
Tetraphenylethene end-capped diketopyrrolopyrrole fluorogens with AIE and large two-photon absorption cross-sections features and application in bioimaging2016In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 133, p. 201-213Article in journal (Refereed)
In this work, a series of new diketopyrrolopyrrole-based dyes have been synthesized by connecting tetraphenylethene to the diketopyrrolopyrrole core. All the four compounds exhibit good aggregation induced emission property with nonemissive in the solution but strong red fluorescence in the aggregate or solid state. Also, these new dyes exhibit large two-photon absorption cross sections (a), in which the a data measured by the open aperture Z-scan technique are determined to be 150, 300, 1140 and 1016 GM for four dyes, respectively. In addition, compound with stilbene and four tetraphenylethene units (DPP-TPE-3) was used as the luminogen and encapsulated into nanoparticles for cell imaging and two-photon excited fluorescence blood vessels imaging. The result indicates that it can be used as the effective fluorescence probe for bioimaging and has great potential for bioapplications. (C) 2016 Elsevier Ltd. All rights reserved.
Kang, Yu
Wang, Qi
On the Mechanism of Protein Adsorption onto Hydroxylated and Nonhydroxylated TiO2 Surfaces2010In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, no 34, p. 14496-14502Article in journal (Refereed)
Protein adsorption onto implant surfaces is of great importance for the regulation of implant bioactivity. Surface modification of implants is a promising way in the molecular design of biocompatible materials against nonspecific adsorption of proteins. On the basis of these fundamental facts, we focus in this work on the different behavior of protein adsorption on hydroxylated and nonhydroxylated rutile TiO2 (110) surfaces through molecular dynamics simulations. Our investigation indicates that the distribution of the water molecules at the interface induced by the surface modification plays an important role in the protein adsorption. The surface with modified hydroxyl groups was observed to have much greater affinity to the protein, as reflected by the larger protein-surface electrostatic interaction and by the larger amount of adsorbed residues. The highly ordered structure of the modified hydroxyl groups on the hydroxylated surface diminishes the possibility of hydrogen bond formation between the surface and the water molecules above it, which in turn makes it easier for the protein to move closer to the surface with hydroxyl modification.
25. Kapilashrami, Mukes
Wang, Yung Jui
Glans, Per-Anders
Fang, Mei
Riazanova, Anastasia V.
Belova, Lyubov M.
Rao, K. Venkat
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
Barbiellini, Bernardo
Lin, Hsin
Markiewicz, Robert
Bansil, Arun
Hussain, Zahid
Guo, Jinghua
Understanding the magnetic interaction between intrinsic defects and impurity ions in room-temperature ferromagnetic Mg1-xFexO thin films2016In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 28, no 15, article id 156002Article in journal (Refereed)
Understanding the nature and characteristics of the intrinsic defects and impurities in the dielectric barrier separating the ferromagnetic electrodes in a magnetic tunneling junction is of great importance for understanding the often observed 'barrier-breakdown' therein. In this connection, we present herein systematic experimental (SQUID and synchrotron-radiation-based x-ray absorption spectroscopy) and computational studies on the electronic and magnetic properties of Mg1-xFexO thin films. Our studies reveal: (i) defect aggregates comprised of basic and trimer units (Fe impurity coupled to 1 or 2 Mg vacancies) and (ii) existence of two competing magnetic orders, defect- and dopant-induced, with spin densities aligning anti-parallel if the trimer is present in the oxide matrix. These findings open up new avenues for designing tunneling barriers with high endurance and tunneling effect upon tuning the concentration/distribution of the two magnetic orders.
26. Kong, Jiahui
Li, Qizhao
Li, Minzhi
Liang, Xu
Zhu, Weihua
Modulation of the structures and properties of bidipyrrin zinc complexes by introducing terminal alpha-methoxy groups2017In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 137, p. 430-436Article in journal (Refereed)
A bidipyrrin nickel complex was synthesized in a high yield by oxidatively coupling between the ligands in the corresponding 2:1 (L:M) type of dipyrrin nickel complex, and further demetallation afforded the free bidipyrrin ligand. Interestingly, when treating the bidipyrrin nickel complex or the free bidipyrrin with FeCl3 in CH2Cl2/MeOH, the symmetric di-alpha-methoxy bidipyrrin could be synthesized in a high yield, with two methoxy groups attached to the terminal pyrrolic alpha-positions. Moreover, the coordination of the unsubstituted and disubstituted bidipyrrins with Zn(OAc)(2),2H(2)O afforded two similar M2L2 type of bidipyrrin helical complexes with different ligand conformations and different Zn center dot center dot center dot Zn distances of 5.353 and 3.357 angstrom, respectively. The difference in the conformations may be related to the electrostatic repulsions between the methoxy substituents. These results indicate that the dyes based on helical bidipyrrin zinc complexes with tunable structures and photophysical properties may be developed simply by modulating the terminal alpha-substituents.
Zhang, Qiong
Savage, Mathew
Yang, Sihai
Tetra- and Octapyrroles Synthesized from Confusion and Fusion Approaches2016In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 18, no 19, p. 5046-5049Article in journal (Refereed)
By oxidation of an alternately N-confused bilane in CH2Cl2, a C-N fused tetrapyrrin was synthesized that bears a 5.5.5-tricyclic ring generated from an intramolecular C-N linkage. When CH3CN was used as the reaction medium, a multiply C-N-fused octapyrrolic dimer was also obtained that contained two 5.5.5.7.5-pentacyclic moieties and a bipyrrole unit generated from the intramolecular C-N linkage and intermolecular C-C linkage, respectively. This could be coordinated with Ni(acac)(2) to afford a mixed-ligand complex.
28. Li, Hong
Cao, Zhan-Qi
Qu, Da-Hui
A Switchable bis-Branched [1]Rotaxane featuring Dual-Mode Molecular Motions and Tunable Molecular Aggregation2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 21, p. 18921-18929Article in journal (Refereed)
A multifunctional bis-branched [1]rotaxane containing a perylene bisimide (PBI) core and two identical bistable[1]rotaxane arms terminated with ferrocene units was prepared and characterized by H-1 NMR, C-13 NMR, and 2D ROESY NMR spectroscopies and by HR-ESI spectrometry. The system is shown to possess several key features: (1) In acetone solution, external acid base stimuli can result in relative mechanical movements of its ring and thread, which can induce extension and contraction movements of the whole system accompanied by a rotational movement of the ferrocene units, thus realizing dual-mode molecular motions, and the optimized conformations at different states are obtained through molecular dynamics simulations employing the general Amber force field. (2) The introduction of PBI enables the system fluorescence encoding through distance-dependent photoinduced electron transfer process from the ferrocene units to the PBI fluorophore. (3) The addition of Zn2+ can increase the degree of aggregation of the system, while adding base hinders aggregation because of the movement of the macrocyde. The tunable aggregated nanostructural morphologies of [1]rotaxane were examined by scanning electron microscopy. These results can pave the way to achieve precise control of integrated and coupling nanomechanical motions at a single-molecule level and provide more insight into controlling the aggregate behavior of switchable mechanically interlocked molecules.
Wu, Ying
A Musclelike [2](2)Rotaxane: Synthesis, Performance, and Molecular Dynamics Simulations2014In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 79, no 15, p. 6996-7004Article in journal (Refereed)
A novel bistable symmetric [2](2)rotaxane was prepared by a threading-followed-by-stoppering strategy and characterized with H-1, C-13, and 2D ROESY NMR spectroscopy and HR-ESI spectrometry. The symmetric [2] (2)rotaxane system consists of an anthracene-based bis(crown ether) as macrocycles, and each of the two dibenzo[24]crown-8 (DB24C8) rings is threaded by the pendant substituents a symmetrically substituted central rotatable ferrocene subunit that possesses two distinguishable recognition sites for the DB24C8 ring: namely, a dibenzylammonium site and an N-methyltriazolium site. The uniform shuttling motion of the thread relative to the two DB24C8 rings in [2](2)rotaxane can be driven by external acid base stimuli, which was evidenced by H-1 and 2D ROESY NMR spectroscopy. Furthermore, molecular dynamics simulations of the [2](2)rotaxane were carried out both in protonated (stretched) and in neutral (contracted) forms. The calculated percentage change in molecular length of the [2](2)rotaxane between the two end-capping bis(methoxyl)phenyl groups is about 48% in the two different states (in acetone), which is much larger than the percentage change (similar to 27%) in human muscle. Moreover, in the two states, the C*-Cp-Cp-C* dihedral angles are computed as -177 degrees in the stretched state and -112 degrees in the contracted state, indicating a correlation between the translational and rotational motions of the [2](2)rotaxane.
Two Switchable Star-Shaped [1](n)Rotaxanes with Different Multibranched Cores2014In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 16, no 18, p. 4940-4943Article in journal (Refereed)
Two novel star-shaped [1](n)rotaxanes with three and four identical [1]rotaxane arms but different multibranched cores were designed, synthesized, and well-characterized. In the two systems, external base acid stimuli result in the uniform relative mechanical movement of the macrocydic rings and threads of their [1]rotaxane arms. The energy-minimized structures of the two rotaxanes in different states were obtained using molecular dynamics simulations in acetone solution, suggesting the construction of more sophisticated molecular machines mimicking the extension and contraction motions.
East China Univ Sci & Technol, Key Lab Adv Mat, Feringa Nobel Prize Scientist Joint Res Ctr, Sch Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China.;East China Univ Sci & Technol, Joint Int Res Lab Precis Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Sch Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China..
Ishida, Masatoshi
Kyushu Univ, Dept Chem & Biochem, Grad Sch Engn, Fukuoka 8190395, Japan.;Kyushu Univ, Ctr Mol Syst, Fukuoka 8190395, Japan..
Kai, Hiroto
Gu, Tingting
Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Jiangsu, Peoples R China..
Li, Chengjie
KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
Baryshnikov, Glib
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology. KTH Royal Inst Technol, Dept Theoret Chem & Biol, Sch Biotechnol, S-10691 Stockholm, Sweden..
Furuta, Hiroyuki
Skeletal Rearrangement of Twisted Thia-Norhexaphyrin: Multiply Annulated Polypyrrolic Aromatic Macrocycles2019In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 58, no 18, p. 5925-5929Article in journal (Refereed)
A hybrid thia-norhexaphyrin comprising a directly linked N-confused pyrrole and thiophene unit (1) revealed unique macrocycle transformations to afford multiply inner-annulated aromatic macrocycles. Oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone triggered a cleavage of the C-S bond of the thiophene unit, accompanied with skeletal rearrangement to afford unique pi-conjugated products: a thiopyrrolo-pentaphyrin embedded with a pyrrolo[1,2]isothiazole (2), a sulfur-free pentaphyrin incorporating an indolizine moiety (3), and a thiopyranyltriphyrinoid containing a 2H-thiopyran unit (4). Furthermore, 2 underwent desulfurization reactions to afford a fused pentaphyrin containing a pyrrolizine moiety (5) under mild conditions. Using expanded porphyrin scaffolds, oxidative thiophene cleavage and desulfurization of the hitherto unknown N-confused core-modified macrocycles would be a practical approach for developing unique polypyrrolic aromatic macrocycles.
32. Li, T.
Ma, X.
Tian, H.
Photoresponsive Supramolecular Assemblies Based on a C3-Symmetric Benzene-1,3,5-tricarboxamide Anchored Diarylethene2016In: Advanced Optical Materials, ISSN 2195-1071Article in journal (Refereed)
A functional C3-symmetric benzene-1,3,5-tricarboxamide-anchored diarylethene molecule (C3-BTE) is synthesized, which evolves into ordered superstructures with tunable morphology properties both in different solvent and via alternative light stimuli. The formation of rod-like assemblies from C3-BTE is reported and the self-assembly property of C3-BTE can be realized through alternative light stimuli in nonpolar solvents such as toluene.
33. Li, Wenlong
Cai, Yunsong
Sterically hindered diarylethenes with a benzobis(thiadiazole) bridge: photochemical and kinetic studies2015In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 3, no 33, p. 8665-8674Article in journal (Refereed)
Four rationally designed diarylethenes (DAEs) 1-4 with a benzobis(thiadiazole) bridge are specifically designed for gaining insights into steric effects on photochromic performances. It is shown that, upon increasing steric hindrance, the exchanging rate between two main conformers in the ring-open form gradually slows down, offering the opportunity for isolating photoactive anti-parallel conformers. Impressively, the separated anti-parallel conformer shows high cyclization quantum yields over the unresolved common DAEs. The typical donor-pi-acceptor (D-pi-A) feature in ring-open DAEs 1-4 endows their prominent fluorescence, which can be conveniently modulated by photocyclization. In the ring-closed form, the excess steric hindrance is found to seriously disrupt the thermal bistability, and particularly 3c fades quickly with a half-life of several hours at ambient temperature. In contrast, both 1c and 2c exhibit excellent stability, which originates from the stabilization effects of intramolecular hydrogen bonds. This work demonstrates the steric effects on the photochemical and kinetic behaviors of DAEs, providing a unique approach to develop photochromic DAEs with high photosensitivity.
Wu, Yue
Li, Mengqi
Wu, Xin-Yan
Enantiospecific photoresponse of sterically hindered diarylethenes for chiroptical switches and photomemories2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 9186 Article in journal (Refereed)
Light-driven transcription, replication and enzyme catalysis are critically dependent upon a delicate transfer between molecular and supramolecular chirality. Chemists have well realized the impressive stereospecificity over many thermally accessible cycloaddition with chiral catalysts, but making light work in the enantiomer control of diarylethene photocyclization has proved to be more challenging. Here, we report a unique sterically hindered diarylethene (BBTE) system with absolute enantiospecific photocyclization and cycloreversion. Moreover, we have fully separated all the five thermally stable isomers, consisting of one achiral parallel conformer, one pair of anti-parallel ring-open enantiomers, and another pair of ring-closed enantiomers, whose absolute chiral configurations are entirely elucidated by single X-ray crystallographic analyses. The photo-responsive feature exhibits a reversible, complete enantio-control transformation without racemism, offering an unrivaled unimolecular enantiospecific platform for potential applications as bistable chiroptical switches and all-photonic photomemories with optical rotation as non-destructive readout.
Applications of Molecular Dynamics in Atmospheric and Solution Chemistry2011Doctoral thesis, comprehensive summary (Other academic)
This thesis focuses on the applications of molecular dynamics simulation techniques in the fields of solution chemistry and atmospheric chemistry. The work behind the thesis takes account of the fast development of computer hardware, which has made computationally intensive simulations become more and more popular in disciplines like pharmacy, biology and materials science. In molecular dynamics simulations using classical force fields, the atoms are represented by mass points with partial charges and the inter-atomic interactions are modeled by approximate potential functions that produce satisfactory results at an economical computational cost. The three-dimensional trajectory of a many-body system is generated by integrating Newton's equations of motion, and subsequent statistical analysis on the trajectories provides microscopic insight into the physical properties of the system.
The applications in this thesis of molecular dynamics simulations in solution chemistry comprise four aspects: the 113Cd nuclear magnetic resonance shielding constant of aqua Cd(II) ions, paramagnetic 19F nuclear magnetic resonance shift in fluorinated cysteine, solvation free energies and structures of metal ions, and protein adsorption onto TiO2. In the studies of nuclear magnetic resonance parameters, the relativistic effect of the 113Cd nucleus and the paramagnetic shift of 19F induced by triplet O2 are well reproduced by a combined molecular dynamics and density functional theory approach. The simulation of the aqua Cd(II) ion is also extended to several other monovalent, divalent and trivalent metal ions, where careful parameterization of the metal ions ensures the reproduction of experimental solvation structures and free energies. Molecular dynamics simulations also provided insight into the mechanism of protein adsorption onto the TiO2 surface by suggesting that the interfacial water molecules play an important role of mediating the adsorption and that the hydroxylated TiO2 surface has a large affinity to the proteins.
The applications of molecular dynamics simulations in atmospheric chemistry are mainly focused on two types of organic components in aerosol droplets: humic-like compounds and amino acids. The humic-like substances, including cis-pinonic acid, pinic acid and pinonaldehyde, are surface-active organic compounds that are able to depress the surface tension of water droplets, as revealed by both experimental measurements and theoretical computations. These compounds either concentrate on the droplet surface or aggregate inside the droplet. Their effects on the surface tension can be modeled by the Langmuir-Szyszkowski equation. The amino acids are not strong surfactants and their influence on the surface tension is much smaller. Simulations show that the zwitterionic forms of serine, glycine and alanine have hydrophilic characteristics, while those of valine, methionine and phenylalanine are hydrophobic. The curvature dependence of the surface tension is also analyzed, and a slight improvement in the Köhler equation is obtained by introducing surface tension corrections for droplets containing glycine and serine.
Through several examples it is shown that molecular dynamics simulations serve as a promising tool in the study of aqueous systems. Both solute-solvent interactions and interfaces can be treated properly by choosing suitable potential functions and parameters. Specifically, molecular dynamics simulations provide a microscopic picture that evolves with time, making it possible to follow the dynamic processes such as protein adsorption or atmospheric droplet formation. Moreover, molecular dynamics simulations treat a large number of molecules and give a statistical description of the system; therefore it is convenient to compare the simulated results with experimentally measured data. The simulations can provide hints for better design of experiments, while experimental data can be fed into the refinement of the simulation model. As an important complementary to experiments, molecular dynamics simulations will continue to play significant roles in the research fields of physics, chemistry, materials science, biology and medicine.
Theoretical studies on electronic structure and x-ray spectroscopies of 2D materials2016Doctoral thesis, comprehensive summary (Other academic)
Extraordinary chemical and physical properties have been discovered from the studies of two-dimensional (2D) materials, ever since the successful exfoliation of graphene, the first 2D material. Theoretical investigations of electronic structure and spectroscopies of these materials play a fundamental role in deep understanding the various properties. In particular, the band structure and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy can provide critical information near the Fermi level. In this thesis, we performed first-principles density functional theory calculations to study the electronic structure and NEXAFS spectra of four materials, including three 2D materials and one bulk material. The three 2D materials are atomically thin bismuth telluride, nitrogen and boron nitride doped graphenes. The bulk material is lithium intercalated graphite, an analogue of lithium doped graphene. Our studies provide important electronic property information of the studied materials, and are helpful for understanding their properties and developing potential applications.
Carravetta, Vincenzo
Li, Cui
Monti, Susanna
KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. CNR-ICCOM, Italy .
Rinkevicius, Zilvinas
Optical Properties of Gold Nanoclusters Functionalized with a Small Organic Compound: Modeling by an Integrated Quantum-Classical Approach2016In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 12, no 7, p. 3325-3339Article in journal (Refereed)
Motivated by the growing importance of organometallic nanostructured materials and nanoparticles as microscopic devices for diagnostic and sensing applications, and by the recent considerable development in the simulation of such materials, we here choose a prototype system para-nitroaniline (pNA) on gold nanoparticles to demonstrate effective strategies for designing metal nanoparticles with organic conjugates from fundamental principles. We investigated the motion, adsorption mode, and physical chemistry properties of gold-pNA particles, increasing in size, through classical molecular dynamics (MD) simulations in connection with quantum chemistry (QC) calculations. We apply the quantum mechanics-capacitance molecular mechanics method [Z. Rinkevicius et al. J. Chem. Theory Comput. 2014, 10, 989] for calculations of the properties of the conjugate nanoparticles, where time dependent density functional theory is used for the QM part and a capacitance-polarizability parametrization of the MM part, where induced dipoles and charges by metallic charge transfer are considered. Dispersion and short-range repulsion forces are included as well. The scheme is applied to one- and two-photon absorption of gold-pNA clusters increasing in size toward the nanometer scale. Charge imaging of the surface introduces red-shifts both because of altered excitation energy dependence and variation of the relative intensity of the inherent states making up for the total band profile. For the smaller nanoparticles the difference in the crystal facets are important for the spectral outcome which is also influenced by the surrounding MM environment.
Hede, T.
Tu, Y.
Glycine in aerosol water droplets: a critical assessment of Köhler theory by predicting surface tension from molecular dynamics simulations2011In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 11, no 2, p. 519-527 Article in journal (Refereed)
Aerosol particles in the atmosphere are important participants in the formation of cloud droplets and have significant impact on cloud albedo and global climate. According to the Kohler theory which describes the nucleation and the equilibrium growth of cloud droplets, the surface tension of an aerosol droplet is one of the most important factors that determine the critical supersaturation of droplet activation. In this paper, with specific interest to remote marine aerosol, we predict the surface tension of aerosol droplets by performing molecular dynamics simulations on two model systems, the pure water droplets and glycine in water droplets. The curvature dependence of the surface tension is interpolated by a quadratic polynomial over the nano-sized droplets and the limiting case of a planar interface, so that the so-called Aitken mode particles which are critical for droplet formation could be covered and the Kohler equation could be improved by incorporating surface tension corrections.
Hede, Thomas
Cloud droplet activation mechanisms of amino acid aerosol particles: insight from molecular dynamics simulations2013In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 65, p. 65- Article in journal (Refereed)
Atmospheric amino acids constitute a large fraction of water-soluble organic nitrogen compounds in aerosol particles, and have been confirmed as effective cloud condensation nuclei (CCN) materials in laboratory experiments. We present a molecular dynamics (MD) study of six amino acids with different structures and chemical properties that are relevant to the remote marine atmospheric aerosol-cloud system, with the aim of investigating the detailed mechanism of their induced changes in surface activity and surface tension, which are important properties for cloud drop activation. Distributions and orientations of the amino acid molecules are studied; these L-amino acids are serine (SER), glycine (GLY), alanine (ALA), valine (VAL), methionine (MET) and phenylalanine (PHE) and are categorised as hydrophilic and amphiphilic according to their affinities to water. The results suggest that the presence of surface-concentrated amphiphilic amino acid molecules give rise to enhanced Lennard-Jones repulsion, which in turn results in decreased surface tension of a planar interface and an increased surface tension of the spherical interface of droplets with diameters below 10 nm. The observed surface tension perturbation for the different amino acids under study not only serves as benchmark for future studies of more complex systems, but also shows that amphiphilic amino acids are surface active. The MD simulations used in this study reproduce experimental results of surface tension measurements for planar interfaces and the method is therefore applicable for spherical interfaces of nano-size for which experimental measurements are not possible to conduct.
KTH, School of Biotechnology (BIO), Theoretical Chemistry.
Molecular Dynamics Study on the Surface Tension of Atmospheric Water Droplets Containing Amino AcidsManuscript (preprint) (Other academic)
Atmospheric amino acids constitute an important fraction of the water-soluble organic nitrogen compounds in both marine and continental aerosols, and have been confirmed as effective cloud condensation nuclei materials in laboratory tests. We here present molecular dynamics study of six types of amino acids in atmospheric water droplets, in order to investigate molecular distributions, orientations and induced changes in surface tension, and to evaluate their indirect effects on optical properties of clouds. These amino acids, including serine, glycine, alanine, valine, methionine and phenylalanine, are categorized into hydrophilic and hydrophobic species according to their affinities to water. Different amino acids show distinct effects on the surface tension; even the same amino acid has different influence on the surface tension of planar and spherical interfaces. Finally the curvature dependence of the surface tension is modeled by a quadratic polynomial function of the inverse of droplet radius, and such relationship is used to improve the Köhler equation in predicting the critical supersaturation of droplet activation.
Surface-Active cis-Pinonic Acid in Atmospheric Droplets: A Molecular Dynamics Study2010In: Journal of Physical Chemistry Letters, ISSN 1948-7185, Vol. 1, no 4, p. 769-773Article in journal (Refereed)
Water vapor in the atmosphere can condensate and form cloud droplets when there is a certain amount of humidity and a presence of cloud condensation nuclei, and organic solutes called surfactants can significantly lower the surface tension of water-one of the parameters determining cloud droplet population. We here present a molecular dynamics study of the behavior of cis-pinonic acid, a commonly found organic compound in cloud condensation nuclei, and its effect on the surface tension of water clusters. Specifically, the decrease in surface tension is found to depend on not only the concentration of the organic compound but also the droplet size due to the spontaneous assembly of the surfactant molecules on the droplet surface. This leads to the conclusion that the partitioning of the surfactant between the bulk and surface plays an important role in the behavior of atmospheric aerosol particles and thus in their availability for cloud formation.
Wang, Bo-Yao
Pong, Way-Faung
Dopant Size Dependent Electronic Structure of Boron Nitride-Doped GrapheneManuscript (preprint) (Other academic)
KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. University of Science and Technology of China, China.
Effects of domain size on x-ray absorption spectra of boron nitride doped graphenes2016In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 109, no 8, article id 081601Article in journal (Refereed)
Doping is an efficient way to open the zero band gap of graphene. The control of the dopant domain size allows us to tailor the electronic structure and the properties of the graphene. We have studied the electronic structure of boron nitride doped graphenes with different domain sizes by simulating their near-edge X-ray absorption fine structure (NEXAFS) spectra at the N K-edge. Six different doping configurations (five quantum dot type and one phase-separated zigzag-edged type) were chosen, and N K-edge NEXAFS spectra were calculated with large truncated cluster models by using the density functional theory with hybrid functional and the equivalent core hole approximation. The opening of the band gap as a function of the domain size is revealed. We found that nitrogens in the dopant boundary contribute a weaker, red-shifted pi* peak in the spectra as compared to those in the dopant domain center. The shift is related to the fact that these interfacial nitrogens dominate the lowest conduction band of the system. Upon increasing the domain size, the ratio of interfacial atom decreases, which leads to a blue shift of the pi* peak in the total NEXAFS spectra. The spectral evolution agrees well with experiments measured at different BN-dopant concentrations and approaches to that of a pristine h-BN sheet.
Kao, Fu-Jen
Chuang, Chien-Chin
He, Sailing
KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
Enhancing fluorescence of quantum dots by silica-coated gold nanorods under one- and two-photon excitation2010In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 18, no 11, p. 11335-11346 Article in journal (Refereed)
Nano-composites of quantum dots (QDs) and gold nanorods (GNRs) or silica-coated GNRs (GNRs_SiO2) were synthesized. The attached GNRs modify the excitation intensity and spontaneous emission of QDs through the surface plasmonic effects. The fluorescence from QDs is enhanced and can be optimized by modifying the thickness of silica coated on GNRs, under both one-and two-photon excitations. The measurements of fluorescence intensity and lifetime demonstrate that the enhancement may be attributed to the matching of the localized surface plasmon resonance of GNR to the excitation wavelength. In addition to enhancing QD-fluorescence in QD-GNR@SiO2, GNRs also present as an effective contrast agent for bio-imaging, through light scattering and or two-photon emission, as well as for photo-thermal therapy. The composite's multifunctional characteristics are highly valuable and to be exploited in bio-applications. (C) 2010 Optical Society of America
Sun, Lu
Cross-Linked Polysaccharide Assemblies in Marine Gels: An Atomistic Simulation2013In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 4, no 16, p. 2637-2642Article in journal (Refereed)
Marine polymeric gels or colloidal nano- and microgels have been shown to contribute significantly to the primary marine aerosol and cloud condensation nuclei over remote marine areas. A microscopic understanding of such biologically derived matter at the sea air interface is important for future development of global climate models, but unfortunately cannot be obtained from modern characterization techniques. In this contribution, we employ molecular dynamics simulations to reveal the atomistic details of marine polymeric gels represented by anionic polysaccharide assemblies. The ionic bonds formed between polysaccharides and metal ions in seawater as well as the hydrophobic contribution to surface area are investigated in detail, and destabilization of the assemblies upon removal of Ca2+ or acidification is explained. These results provide insight into physicochemical properties of polysaccharide-Ca2+ structures and enable future studies of their roles of in the wetting process of cloud droplet activation.
E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China.;E China Univ Sci & Technol, Inst Fine Chem, Shanghai Key Lab Funct Mat Chem, Shanghai 200237, Peoples R China..
Theoretical insight into the enhanced hindrance, thermal stability and optical properties of diarylethene with a benzobis(thiadiazole) bridge and benzothiophene rings2016In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 125, p. 348-355Article in journal (Refereed)
To rationalize the effects of intramolecular steric hindrance on the performance of diarylethene photoswitches, we here present a density functional theory study on the thermal bistability and optical properties of a photochromic diarylethene BBTE consisting of a benzobis(thiadiazole) bridge and benzothiophene rings, in which prominent steric hindrance exists owing to the extended structures of is-conjugated groups. Our calculations not only provide rational explanations for the isolation of enantiopure anti-parallel conformers of the open-ring isomer, but also elucidate the detailed pathway of a two-step ground-state ring-opening process, where the thermal stability of the closed-ring isomer is guaranteed by an overall free energy barrier of around 113 kJ mol(-1) (27 kcal mol(-1)). In addition, the tunable intramolecular charge transfer of the donor acceptor structure formed by the benzobis(thiadiazole) bridge and the bulky benzothiophene rings is also addressed within time-dependent density functional theory. Charge transfer excitations in the open- and the closed-ring isomers are characterized as long-range and medium-range, respectively. We show that the diarylethene derivative under investigation can serve as a promising platform for future development of optoelectronic materials.
Minaev, Boris F.
E China Univ Sci & Technol, Adv Mat Lab, Shanghai 200237, Peoples R China.;E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China..
Density Functional Theory Study of Photophysical Properties of Iridium(III) Complexes with Phenylisoquinoline and Phenylpyridine Ligands2011In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 115, no 42, p. 20724-20731Article in journal (Refereed)
Linear and quadratic response time-dependent density functional theory is applied to study the photophysical properties of iridium complexes with phenylisoquinoline and phenylpyridine ligands. The ground-state geometries, frontier molecular orbitals, absorption spectra, phosphorescence wavelengths, and radiative rate constants are computed to facilitate better understanding of the structure-property relationships of these iridium complexes used in organic light-emitting diodes (OLEDs) to enhance spin-orbit coupling and triplet state emission. The agreement obtained between calculated and available experimental data indicates a possibility to guide the design of phosphorescence-based OLEDs by predicting their relevant properties through quantum mechanical calculations.
E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China.;E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China..
Theoretical Study of Phosphorescence of Iridium Complexes with Fluorine-Substituted Phenylpyridine Ligands2011In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 16, p. 2517-2524Article in journal (Refereed)
Time-dependent density functional theory (TD-DFT) with linear and quadratic response approaches was applied to calculate absorption and luminescence spectra of a number of facial and meridional iridium complexes with fluorine-substituted phenylpyridine (F(n)ppy) ligands. The absorption and luminescence spectra were studied to simulate the photophysical properties of electroluminescent devices fabricated on the basis of these iridium complexes used to increase spin-orbit coupling and the triplet-state blue emission of the corresponding organic light-emitting diodes (OLEDs). By using the quadratic response technique, the phosphorescence radiative rate constant and lifetime of the studied iridium complexes were calculated through spin-orbit coupling perturbation and compared with the measured data in experiments. A satisfactory agreement between these data permits us to guide improvements in the design of phosphorescence-based OLEDs by predicting the structure-property relationships through quantum chemical calculations.
Prendergast, David
Electronic Structure of Lithium Intercalated Graphite from First-Principles SimulationsManuscript (preprint) (Other academic)
Kongsted, Jacob
Natarajan Arul, Murugan
Binding Mechanism and Magnetic Properties of a Multifunctional Spin Label for Targeted EPR Imaging of Amyloid Proteins: Insight from Atomistic Simulations and First-Principles Calculations2012In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 8, no 11, p. 4766-4774Article in journal (Refereed)
Electron paramagnetic resonance (EPR) imaging techniques provide a promising approach to detect amyloid structures which are of paramount importance in early-stage diagnosis of conformational diseases. Here, we report a combined molecular dynamics and density functional theory/molecular mechanics computational scheme for evaluation of the binding mechanism between a multifunctional spin label and the target amyloid protein. In addition, we consider evaluation of EPR spin Hamiltonian parameters with the aim of providing a better microscopic understanding and interpretation of EPR spectroscopy. The results from molecular dynamics simulations suggest that the oligothiophene conjugate part of the spin label interacts with hydrophobic residues of the amyloid protein through hydrophobic attraction and that both the N-O bond length and the N-O out-of-plane tilt angle in the nitroxide group are slightly diminished after, complexation with the protein. The translational and rotational motions of the protein bound spin label are considerably slowed compared to those of the free spin label in aqueous solution, but interestingly, hydrogen bonds formed between the nitroxide oxygen group and the surrounding water molecules are hardly affected by the presence Of the amyloid protein. First principles calculation's suggest that EPR spin Hamiltonian parameters including the nitroxide nitrogen hyperfine coupling tensor A(N) and electronic g tensor suffer noticeable changes upon complexation with the protein. The magnitude of the A(N) tensor is found,to:be. closely related to the nitroxide N-O out tilt angle, while the g tensor is affected by both the nitroxide N-O bond length as well as the interaction between the spin label and the amyloid protein With this work we show that state-of-the-art simulation techniques represent a promising way of providing a detailed understanding of the microscopic mechanisms responsible for the formation and stability of a spin label complexed with amyloid structures as well as the magnetic properties of the free and protein-bound spin label.


text:
Survitec Press Releases
Canadian Navy Chooses Survitec's Market Leading Submarine Escape Suits
Survitec Group has secured another new contract to supply its MK11 Submarine Escape Immersion Equipment (SEIE) to one of the most discerning navies in the world. The Royal Canadian Navy, after extensive research, including its own independent trials, issued a single source tender to Survitec Group.
The Canadian fleet will upgrade its existing RFD Beaufort MK10 equipment with the new SEIE MK11 variant and has also purchased a full accompaniment of training suits. Since its launch in 2008 the RFD Beaufort MK11 SEIE, the latest and most advanced equipment in the Survitec range, has been adopted by many nations with more to follow in 2012. It is part of a more extensive range of Submarine Escape and Immersion Equipment offered by the Survitec Group.
Submarine escape and survival manager at Survitec Group, Chris Pugh-Bevan, commented: "We are extremely proud to supply our Submarine Escape and Immersion Equipment to the Royal Canadian Navy. We will continue to focus our research and design efforts into SEIE to ensure we maintain our status as world leaders."
Survitec pioneered the development of Submarine Escape technology in 1952. Designed to provide protection for submariners from a stricken submarine, Survitec's products include single skinned suits with integrated life rafts, escape jerkins, inflatable abandonment suits, external submarine life raft systems and freeboard extenders.
The suits are designed and manufactured at Survitec Group's facility on Beaufort Road in Birkenhead, UK. Survitec has in excess of 30,000 units of submarine escape equipment in use in the market place, and supplies to 30 of the world's navies.

redpajama_set_name: RedPajamaCommonCrawl


Sigsbee and I watched the last two just now, and are all caught up!
I want next season right now.
They really do love cliffhangers on this show.
When it cut to the burning car I groaned and turned the show off. Was there anything after that to make it not incredibly stupid?
I think this might have killed it for me.
Um that was the end of the season. Cliffhanger for next year.
Castle does funny great. Castle does drama gut wrenchingly bad.
I think we've come to greatly prefer the funny ones, but some of the dramatic ones have been really good, too. I loved ther play on Taken, for example.
I loved that the show ended with Kate crying over the burning car followed by an announcer telling us that Castle and Beckett will return next season.
Next year the show will be called Beckett. Because Castle is DEAD!
Nah, it will still be Castle. It's just that then his ghost will follow her around and mess with Ryan and Esposito.
It will be 24 episodes of them in mourning. It's going to be really depressing, and critics will love it.
That might get me to watch again.
The show is merging with 24?
Basically, it will be Lost set in New York.
Also belongs in this week's hump day responses.
I know it was the finale. At that moment, I simply didn't care if there was any more. And regarding the obviousness, yes, it is incredibly obvious, which is why I found it to be such a stupid beat.
Yarp. The funny episodes are pretty consistent but the drama... it's been so bad so much more often.
Haven't watched the last two episodes yet. I saw HRG guy in the preview and just groaned.
I will admit that their relationship has not killed the series. I really thought it would.
Ditto. My first reaction was, "FFS. Really??" Why not have it so Castle's Dad shows up at the wedding, maybe interrupting their first dance with a nice messy bullet wound or something? At least then they'd be married - esp. after all the "Oh no, the dress! Oh no, the venue! Oh no, Ryan's suit!" stuff.
I'm officially annoyed with this show.
And yeah, obviously he's not dead - which is what makes it so annoying.
I'm glad I'm not alone here. They spent the entire season milking the wedding drama. Get it over with and move on.
Hint at some horrible thing they'll have to deal with when they get back from their honeymoon. Or like Mimble suggests interrupt the reception with your cliffhanger. There's gotta be 100 ways they could have ended that weren't this incredibly lame.
Finally caught up with the DVR, I'm all in on "FFS". The show got so ridiculous I apparently literally have no empathy left for the characters.
See, if you don't like the episodes like that 70s show, I submit that you may not be appreciating Castle for the cotton candy corndog that it is, most of the time.
Yeah, the 70s show was fun.
Maybe I didn't get it across. I loved it and it was hilarious. It was also the dumbest episode yet. I mean that in the nicest way possible.
I love Castle. But truly, this was the lamest episode I can remember.
You people are all going to be eating crow when the next season opens with a visual of Nathan Fillion's mangled and horribly burned corpse, the news that Beckett hung herself, and Ryan and Espisito (sp?) have been fired from the force after an IA investigation turned up the myriad of ways that those two violated police procedures helping the previously untoasted Castle with his hijinks. The series will now be Martha and Alexis driving around in a van solving mysteries using Martha's amazing acting skill and Alexis' newfound juggling talent.
I wanted to be the first to say "Would watch!"
You people are all going to be eating crow when the next season opens with a visual of Nathan Fillion's mangled and horribly burned corpse, the news that Beckett hung herself, and Ryan and Espisito (sp?) have been fired from the force after an IA investigation turned up the myriad of ways that those two violated police procedures helping the previously untoasted Castle with his hijinks. The series will now be Martha and Alexis driving around in a van solving mysteries using Martha's amazing acting skill and Alexis' newfound juggling stripping talent.


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Macros are special strings in a creative's code snippet that DFP later replaces with another value based on a creative's settings. Macros can be included in any code that's processed by the ad server during the delivery process: third-party or custom creative code, DoubleClick Rich Media code, click-through URLs, or DFP tags.
For each macro, DFP have provided suggestions on how you might use it, but macros can be put to whatever uses are most valuable for you.
Note that the macros %%HEIGHT%% and %%WIDTH%% will cause problem while saving the VAST or VPAID tag provided by the client.
1) Hard Coding the player dimension so that the creative will get saved inside DFP.
Many VAST servers use "tag variables" to optimize fill and provide more information on how ads are being viewed. JW Player supports a number of variables that can be added to your VAST tag URL. Once an ad call is made by JW Player, the variables will be replaced accordingly.
The ID of the companion div, for example to allow VPAID ads to talk to companions.
The domain name the player is embedded on.
The height of the video player on the page in pixels.
The width of the video player on the page in pixels.
A list of popular third party macros can be found in the SpotX Macros Guide. When the appropriate parameters are replaced, the sample tags below should return a test ad 100% of the time.
[TIMESTAMP] or [CACHEBUSTING] or [CACHE_BREAKER] :A timestamp value for cache busting.
[DOMAIN] :The domain part from the publisher URL.
[PUBLISHER] : The publisher name or URL. Use this for page URL.
[SITE] :The site name or URL.
[dnt] – A do not tack macro. Will return 0 or 1 depending on user.
[gdpr] – A flag for European Union traffic consenting to advertising.
[consent] – A consent string passed from various Consent Management Platforms (CMP's).


text:
"Your Dying Charlotte"
Forgotten Lives Behind the Photographs and Artifacts
Tag: soldiers
A Union Soldier Remembers
"About this time, we were visited by heavy thunderstorms. Having shelter, we were obliged to hunt high places upon the ground to spread our blanket, and with knapsack for a pillow, lay down wet and shivering with our gum blanket over us for the rain to beat upon."
Courtesy Library of Congress.
Daniel H. Mowen was born 28 November, 1839. Both his parents were dead by the time he was 12. By August 1862, Mowen had relocated from his native Pennsylvania to Frederick County, Maryland, where he enlisted in C. F. Anderson's Company I of the 7th Maryland Regiment for a three-year term. During the course of his service, he was wounded at the Battle of Spotsylvania Court House, heard the last speech of Abraham Lincoln at the White House, did guard duty at the Old Capital Prison on the night of the president's assassination, and was present during the trial of the conspirators.
Catoctin Clarion, 23 August, 1906.
This account was written for the Hagerstown Globe newspaper late in Mowen's life but does not appear to have been published elsewhere. It is preserved in the archives of the Middletown Valley Historical Society. The reenactment group, the 7th Maryland Reg't Volunteer Infantry, published a transcribed PDF version of this manuscript on their site. I feel it is valuable to digitally publish this account again here for increased access by researchers and to further document the rich history and experiences of the people of Myersville and Wolfsville for that area's historical society. This version has been lightly edited for spelling and punctuation to increase readability.
1863. Like all organizations, we had men that were not true to the colors. On the night of the 5th of February, the sentinel on duty at the stables deserted, appropriating Major Dallam's horse to help him on his way. On February 24th a mule took offense at me passing somewhere within fifty feet of his rear, kicked me on the leg, but missed his mark so far as to not break any bones. Considering the source from which it came, all that we could do was to pass on the best we could. We were not in a very moveable condition for several days.
On the 28th of February, we had the pleasure of witnessing the presentation of a flag from California to the brave boys of the First Maryland Regiment, who had already gained considerable distinction.
After the Civil War, Daniel H. Mowen lived in both Myersville and Wolfsville, Frederick County, Maryland.
The 4th of April was cloudy and cold. We broke camp on Maryland Heights and moved our camp to Bolivar Heights, on the Virginia side of the Potomac. We pitched our tents upon the wet ground. It began to snow in the evening and the next morning there was wet snow of about eight inches. We had nothing but a narrow board to lie upon the wet ground for a [bed] with wet ground below, wet snow above. I lay down cold and shivered to sleep. But that sleep was of short duration. I awoke with the most severe pains through my shoulder and breast that I thought a mortal could experience. But fortunately, by calling upon the surgeon, I got relief.
Owing to raids by Imboden and Jones, on April 27th we left Harpers Ferry, on the B&O Railroad, reaching Cumberland in the evening and Oakland the next morning. We left Oakland on the morning of the 29th on foot through rain and mud for Cranberry Summit. Here the auctioneer of Company I, Joseph Boward, put up at public auction one of the Sixth Virginia home guards. He was reported to have aided the enemy at plunder, and killed a citizen's cow, was arrested and afterward turned over to the civil authorities.
After pleading for a bid, he was knocked off to Jeff Davis for three cents. Thinking it was too good of a bargain to let his uniform go with the man, his clothes were put up, soon reaching twenty-five dollars. They were knocked off to Uncle Sam. It was rather humiliating, but he had to stand it.
Continue reading "A Union Soldier Remembers"
Author Ann Longmore-EtheridgePosted on April 9, 2019 September 9, 2019 Categories Civil War Soldiers Biographies, Maryland HistoryTags 1860s, Abraham Lincoln, Battle of Spotsylvania Court House, Battle of the Wilderness, family, Frederick County, history, Koogle family, Maryland, military, Mowen family, people, Presidents, soldiers, U.S. Civil War, Union, United States, USA, Victorian era, Washington County1 Comment on A Union Soldier Remembers
When an Apple Falls Far From the Tree: Part One
The night was hot and sultry, but with a luminous Moon. George Bittle closed up shop but did not go to bed. As he had done on recent occasions, Bittle sat on his front porch, armed with a breech-loading gun, to watch over his store.
George Waters Bittle General Store, Myersville, Maryland, circa 1905.
On 12 July, 1946, the Hagerstown (Maryland) Daily Mail printed the obituary of local notable George Waters Bittle, who died on 10 July in Frederick City Hospital, aged 79. Bittle was a long-standing board member of the Myersville Savings Bank and had operated a general merchandise store on Main Street for more than half a century. In hindsight, the newly deceased Bittle had likely enjoyed an extra 42 years of life. Against the odds, Bittle survived three bullets fired into him during an attempted burglary of his business in August 1904.
Bittle's near murder was the byproduct of a series of break-ins in Myersville. Frankly, the town had a crime problem. The young man most likely responsible for these thieveries was the child of another notable citizen—a Civil War hero who'd won the Congressional Medal of Honor for exceptional battlefield bravery—Captain Joseph Koogle.
Continue reading "When an Apple Falls Far From the Tree: Part One"
Author Ann Longmore-EtheridgePosted on March 22, 2019 September 20, 2019 Categories Civil War Soldiers Biographies, Maryland History, Murder and MayhemTags 20th Century, Battle of Five Forks, Bittle family, business, crime, Frederick County, history, Koogle family, Maryland, Myersville, parents, people, soldiers, U.S. Civil War, United States, USA2 Comments on When an Apple Falls Far From the Tree: Part One
"This Old Patriot Stood His Ground"
In 1864, George Blessing, "Hero of Highland," bravely battled Confederate raiders on his farm near Wolfsville, Frederick County, Maryland, but the real man and his deeds became almost unrecognizable in popular retellings.
Still image courtesy of the History Channel.
John Caleb Leatherman (1852-1952), who was a child during the Civil War and a neighbor of the man who would earn the sobriquet "Hero of Highland," told a Hagerstown Daily Mail reporter in 1950, "Boy, that ol' George Blessing was a spunky one. Those Rebels were trying to get a hold of all the horses they could. When [my] Father heard about it, he took his horses up into Pennsylvania. Not George Blessing—he just stood pat on his own farm there."
A barnyard shootout at Blessing's Highland Farm took place on 9 July, 1864, the same day that the Battle of Monocacy was fought only a few miles away on the outskirts of Frederick City. At the end of that month, the Frederick Examiner ran a letter to the editor, suggesting "the raising of a sum, by the contributions of Union men … for the purpose of procuring a medal, with the appropriate device and inscription, to commemorate [Blessing's] noble feats of that occasion."
Frederick Examiner, 27 July, 1864.
In the years that followed, the grandiosity of the tale and the pious nature of the hero was escalated by his niece, the writer Nellie Blessing Eyster, who published grandiose versions in both a noted ladies magazine and in her 1867 novel Chincapin Charlie. In the latter, she called him "one of Nature's noblemen," wrote that he was possessed of a "strange power" from "living so close to Jesus," and that as he was "thoroughly imbued with the spirit of '76, loving the government for which his fathers died, next to the God whom he so devoutly worshipped … he defended his home from what he sacredly believed an unrighteous invasion."
Continue reading ""This Old Patriot Stood His Ground""
Author Ann Longmore-EtheridgePosted on November 16, 2018 January 22, 2019 Categories Civil War Soldiers Biographies, Maryland History, Murder and Mayhem, U.S. Civil WarTags 1860s, 1864 Maryland Campaign, 19th century, 47th Battalion Virginia Cavalry, Blessing family, Bussard family, Christopher Armour Newcomer, Cole's Cavalry, Confederacy, family, Frederick County, geneology, George Blessing, history, Kesselring family, Maryland, military, people, Point Lookout, prision camp, slavery, soldiers, U.S. Civil War, Union, USA, Victorian era, Wolfsville2 Comments on "This Old Patriot Stood His Ground"
Official Dark Boots
How the awesome power of highly caffeinated coffee may continue to shape Union soldiers' Afterlives.
A Union soldier with his hardtack, salted pork, gun, and coffee pot, known as a "mucket." Courtesy Heritage Auctions.
On a chilly, drizzly day in March 2018, my lifelong boon companion Julie and her daughter, my honorary niece, joined me for a day trip to Gettysburg. My niece had never visited the town or battlefield before. In addition to seeing the historical sites, she was keen to undertake some EVP/ITC recording with her "Weird Aunt," as I'm known to her circle. That day, we combined the driving tour and the ghost hunting, practicing what I call a "drive-by"—rolling the vehicle to a stop, lowering the window, turning on an iPad ghost box app and digital recorder, and inviting anyone present to speak.
(Electronic voice phenomenon, or EVPs, are recorded human voices that appear with no explanation across the spectrum of audiovisual technologies. The messages are often evidential, personal, and thought-provoking. Instrumental Transcommunication, or ITC, uses various forms of electronic devices, such as the so-called ghost box, to generate white noise or randomly generated phonemes from which it is theorized that spirits can shape speech.)
After purchasing an excellent driving tour CD with the marvelous Stephen Lang narrating, we set off, shortly reaching McPherson's Ridge and the railway cut near the McPherson farmhouse, which saw heavy engagement during the first day of fighting. Before the battle, the area was excavated, but no rail tracks had been laid. This made a perfect spot for entrenchment by both sides as the battle lines shifted throughout the day.
Continue reading "Official Dark Boots"
Author Ann Longmore-EtheridgePosted on September 28, 2018 December 29, 2018 Categories ghosts, Unidentified Ambrotypes, Unidentified TintypesTags 19th century, Civil War, coffee, electronic voice phenomenon, Gettysburg, ghost box, ghosts, history, Instrumental Transcommunication, military, Pennsylvania, soldiers, United States, USA7 Comments on Official Dark Boots
Is the Past More Than Prologue?
In a cornfield by the old Pry House in Keedysville, Maryland, the walls between September 1862 and today can sometimes grow thin.
Sean Byrne at Pry House Field Hospital Museum, Keedysville, Maryland, June 2018.
On Tuesday, 16 September, 1862, farmer Phillip Pry, Jr., and his wife Elizabeth, née Cost, found that the Civil War was standing on their doorstep. Since the summer of 1844, the couple had dwelt happily in their imposing home, high on a hill, which Phillip and his brother Samuel had built on their father's land. The road between Boonsboro and Sharpsburg ran along the foot of the hill, and as Philip and Elizabeth could see from their front porch, it had become an artery for the Confederate war machine. Soldiers in grey, wagons, armaments, ambulances, horses—for a day and night they moved past the Prys' house in a kaleidoscope of pending misadventure.
Philip and Elizabeth Cost Pry, circa 1868. Courtesy Pry House Field Hospital Museum.
The next day, the road was crammed with soldiers in blue trundling along with the Union Army's horses, vehicles, and ordnance. They were headed to attack the Confederacy at Sharpsburg—a bloodbath now known as the Battle of Antietam. Shortly, the Prys' home would be commandeered as a headquarters and a field hospital by no less than the flamboyant George Armstrong Custer. From that moment, the Prys' bucolic life on the hill was over.
Continue reading "Is the Past More Than Prologue?"
Author Ann Longmore-EtheridgePosted on August 21, 2018 December 29, 2018 Categories ghosts, Murder and MayhemTags Battle of Antietam, Battle of South Mountain, Civil War, Confederacy, Frederick County, Genealogy, ghosts, history, Keedysville, Maryland, military, paranormal research, Pry family, Sharpsburg, soldiers, Union, United States, USA, Washington County4 Comments on Is the Past More Than Prologue?
Who Was Private Raisin Pitts?
My attention was drawn by the unusual name carved into one tombstone: Raisin Pitts, a Confederate private who died 26 September, 1862, now buried in a Yankee town in a Union state, far from home.
The grave of Raisin Pitts, Mount Olivet Cemetery, Frederick, Maryland, photographed by the author on Confederate Memorial Day, 28 April, 2016.
Recently, and quite serendipitously, I visited Mount Olivet Cemetery—the preeminent burial grounds of Frederick County, Maryland. Francis Scott Key, who in 1812 wrote the poem that became the National Anthem, reposes there. Also interred at Mount Olivet are prosperous Victorians and Edwardians, Colonial and Federal-era area residents moved from their original gravesites in small family plots and cemeteries around the county, and Civil War soldiers who fought for the Confederacy but breathed their last as Union captives.
It was Confederate Memorial Day, a solemn remembrance of which I was unaware when a friend and I decided to visit the cemetery. We found Mount Olivet's Confederate graves bedecked with flags. Reenactors laid wreaths after a small, bagpipe-led parade.
Confederate graves at Mount Olivet. Raisin Pitts is buried in this row.
My attention was drawn by the unusual name carved on one tombstone: Raisin Pitts, a Confederate private who died 26 September, 1862, now buried in a Yankee town in a Union state, far from home. My curiosity propelled by his unusual—and unlikely—name, I decided to search for more about Private Pitts.
Continue reading "Who Was Private Raisin Pitts?"
Author Ann Longmore-EtheridgePosted on May 15, 2018 December 31, 2018 Categories Civil War Soldiers BiographiesTags 1860s, 19th century, 6th Alabama Infantry, Alabama, Battle of Antietam, Battle of Seven Pines, Battle of South Mountain, Boonsboro, Civil War medicine, family, family history, Frederick, Genealogy, history, Maryland, military, Mount Olivet Cemetery, Pitts family, Point Lookout, prision camp, Sharpsburg, soldiers, South Carolina, U.S. Civil War, United States, USA, Victorian era7 Comments on Who Was Private Raisin Pitts?
Remembering the Christmas Truce of 1914
During World War I, soldiers on both sides ceased dealing death for one joyous Christmas Day.
Camaraderie outside the trenches, Christmas Day 1914. A beautifully colorized version of this photo can be found here.
It came and then was gone, but for a while, death held no dominion on the battlefields of France. Soldiers on both sides were entrenched, following killing orders from generals and cousin kings. "You no shoot, we no shoot," the signs Germans troops held up supposedly read. So, the British did not shoot. Instead, they all met in the middle—a muddy No Man's Land. They decorated tiny Yule trees and exchanged cigarettes, cigars, tinned foods, and even helmets. They buried their dead; they sang carols and played football, too.
According to historian Gerard DeGroot, a professor at the Unversity of St. Andrews, "The truce was, first and foremost, an act of rebellion against authority. In the trenches, though peace on earth seemed a ridiculous fantasy, impromptu ceasefires had been occurring as early as December 18. The British High Command, alarmed that the holiday might inspire goodwill, issued a stern order against fraternization. Officers were warned that yuletide benevolence might 'destroy the offensive spirit in all ranks'. Christmas, in other words, was to be a killing time.
"The Germans, however, were stubbornly festive. In an effort to bolster morale, truckloads of Christmas trees were sent to the Kaiser's forces. All along the line, Germans were acting in a bizarrely peaceful fashion. Guns fell silent. Candles and lanterns taunted British snipers. Late on Christmas Eve, Germans singing 'Stille Nacht' ['Silent Night'] echoed across no man's land. The British, initially perplexed, soon joined in."
Continue reading "Remembering the Christmas Truce of 1914"
Author Ann Longmore-EtheridgePosted on December 24, 2017 January 3, 2019 Categories Unidentified Photos, VariousTags 1914 Christmas Truce, Christmas, France, Germany, Great Britain, history, military, soldiers, war, Western Front, World War I1 Comment on Remembering the Christmas Truce of 1914
Who was "Dying Charlotte"?
Charlotte was from a respectable British family of the Regency period—a clan that could afford gold and faceted jet mourning jewelry to be commissioned. Charlotte was probably a young woman when she realized she was dying, possibly of consumption. The simple style and shape of the brooch dates it to around 1815.
In the Collection Highlights below and on the Contact page, you can see the brooch, which reads on its reverse: "Dear Henry, accept this as a token of sincere Love from your Dying Charlotte."
Customizer.
A. Longmore-Etheridge Collection Highlights
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Unidentified Photos, Various (19)
Unidentified Tintypes (12)
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