Intramolecular Energy and Solvent‐Dependent Chirality Transfer within a BINOL‐Perylene Hetero‐Cyclophane

Abstract Multichromophoric macrocycles and cyclophanes are important supramolecular architectures for the elucidation of interchromophoric interactions originating from precise spatial organization. Herein, by combining an axially chiral binaphthol bisimide (BBI) and a bay‐substituted conformationally labile twisted perylene bisimide (PBI) within a cyclophane of well‐defined geometry, we report a chiral PBI hetero‐cyclophane (BBI‐PBI) that shows intramolecular energy and solvent‐regulated chirality transfer from the BBI to the PBI subunit. Excellent spectral overlap and spatial arrangement of BBI and PBI lead to efficient excitation energy transfer and subsequent PBI emission with high quantum yield (80–98 %) in various solvents. In contrast, chirality transfer is strongly dependent on the respective solvent as revealed by circular dichroism (CD) spectroscopy. The combination of energy and chirality transfer affords a bright red circularly polarized luminescence (CPL) from the PBI chromophore by excitation of BBI.


S1. General information
Unless otherwise noted, all the chemical compounds were purchased from commercial suppliers and were directly used without further purification. Column chromatography was performed on silica gel (particle size 0.040−0.063 mm). NMR spectra were recorded on Bruker Avance III HD 400 MHz and 600 MHz spectrometers.
NMR data analysis are presented as following, s: singlet, d: doublet, t: triplet, m: multiplet, br: broad signal. Recycling gel permeation chromatography (GPC) was carried out on a Shimadzu semi-preparative recycling chromatography setup with two or three semipreparative columns (Japan Analytical Industries Co., Ltd.; JAIGEL-2H and JAIGEL-2.5 H) with CHCl 3 as eluent. Recycling semipreparative HPLC was carried out on a JAI LC-9105 instrument. Chiral resolution was carried out using a Trentec Reprosil-100 Chiral-NR 8μm-column. Mass spectra were measured on a Bruker Daltonics micrOTOF-QIII focus instrument for high-resolution ESI or a Bruker Daltonics ultrafleXtreme mass spectrometer using DCTB as a matrix for highresolution MALDI. UV/Vis absorption spectra were recorded on JASCO V-670 and V-770 spectrometers. Fluorescence spectra and lifetime measurements were measured with an Edinburgh Instruments FLS980 spectrometer. Lifetimes were measured using EPL picosecond pulsed diode laser (505.8 nm and 378.2 nm) as a light source.
Fluorescence quantum yields were determined relative to common fluorescence standards for optically dilute solutions (A<0.05). Theoretical calculations were performed by Gaussian 16 program and 09 program 1 at B3LYP/6-311 G(d,p) level.
Circular dichroism was measured on a JASCO J-810 spectrophotometer. Circularly polarized luminescence was measured on a JASCO CPL-300 spectrophotometer.

S2. Synthesis and characterization
Perylene bisanhydride 1 2 and BINOL bisanhydride 4 3 are known compounds and were synthesized according to literature methods.

S3
Synthesis of perylene diamine 3: Perylene bisanhydride 1 (100.0 mg, 0.10 mmol), tertbutyl 4-(aminomethyl)benzylcarbamate 2 (55.0 mg, 0.22 mmol) and imidazole (300.0 mg, 4.40 mmol) were added to 100 mL toluene in a 250 mL round-bottom flask. The mixture was refluxed under a nitrogen atmosphere for 16 h. After completion of the reaction, the mixture was cooled to RT and solvent was removed under reduced pressure. The crude product was washed with chloroform (100 mL) and 1 M HCl (100 mL). The organic phase was collected and dried over anhydrous Na 2 SO 4 . After filtration and removing the solvent under vacuum, the crude product was purified by column chromatography (silica gel, eluent CH 2 Cl 2 /MeOH = 20:1, v/v), giving a red solid (135.0 mg, 0.095 mmol). This perylene bismide compound (50.0 mg, 0.035 mmol) was further dissolved in 20 mL CH 2 Cl 2 in a 100 mL round-bottom flask, then 3 mL trifluoroacetic acid (TFA) was added. The color of the solution changed from red to dark blue immediately. After stirring at RT for 30 min, the solvent was removed under reduced pressure, giving a dark red solid in a quantitative yield (50.7 mg, 0.035 mmol). 1  Synthesis of BBI-PBI cyclophane: Perylene diamine 3 (84.0 mg, 0.058 mmol), racemic binaphthol bisanhydride 4 (26.0 mg, 0.058 mmol) and imidazole (1.1 g) were dispersed in 600 mL toluene in a 1000 mL round-bottom flask under a nitrogen atmosphere and the mixture was refluxed overnight. After cooling to RT, toluene was removed under vacuum, the residue was dissolved in chloroform (100 mL) and washed with 1 M HCl (100 mL). The organic phase was collected and dried over anhydrous Na 2 SO 4 . After filtration, the solvent was removed under vacuum and the product was purified by column chromatography (silica gel, eluent CH 2 Cl 2 /MeOH = 50:1) and recycling GPC to give a dark red solid, yield: 8 % (7.6 mg, 4.6 μmol). 1   For better visualization, the side view CPK modes of P-BBI-P-PBI and P-BBI-M-PBI are shown at the top of each chemical structure. BBI is colored in cyan and PBI is colored in magenta. The 4-tert-butylphenoxy groups on bay position were omitted for clarity. Further, the cartoon figures on left and right sides represent the core twisting of BBI and PBI chromophores from a side view, in which solid and dashed blue lines indicate naphthalene imide planes of BBI, solid and dashed red lines indicate naphthalene imide planes of PBI.  S2). However, the racemization barrier for tetraphenoxy-substituted PBI is only about 60 kJ/mol, 5 which is not high enough for enantiomeric resolution on a chiral HPLC column. As a result, only two compounds, P-BBI-PBI and M-BBI-PBI cyclophanes were obtained after resolution on a semi-preparative chiral column (Fig.  S3), for which the P/M-ratio of the perylene subunit depends on the degree of chirality transfer imparted by the BBI unit. 3 Table S1. Optical properties of reference compounds in CH 2 Cl 2 at 293 K.         TD-DFT calculations indicate that the major MO contribution to the S1 state is the HOMO-LUMO transition (Table S3). These two frontier orbitals are mainly located on the PBI chromophore (Fig. S9). Accordingly, the transition dipole moment of the S 0 -S 1 transition of P-BBI-M-PBI cyclophane is polarized along the long axis of PBI, which is only slightly interfered by the presence of the BBI chromophore.  Figure S10. CD spectra of P-BBI-PBI cyclophane in a) CHCl 3 (stabilized with amylene, filtered over Alox), and b) CHBr 3 (stabilized with 4 wt% EtOH), [P-BBI-PBI] = 2.6  10 -4 M, cuvette path length 1 mm, 293K. The results are similar to those in CHCl 3 stabilized with 4 wt% ethanol (shown in Fig. 3a in main text).  The ee value of PBI subcomponent at 263 K is estimated to be 3.24×10 -4 /0.0018 = 0.18, where 0.0018 is the absorption dissymmetry factor of an enantiopure P-helical tetraphenoxy-substituted PBI based on our previous report. 5 Figure S13. Calculated CD spectrum of P-BBI-M-PBI cyclophane without consideration of the solvent, TD-DFT, Gaussian 09, B3LYP/6-311+G(d,p) level.