Supporting Information Highly selective molecular sieving of cis- over trans-1,2-dichloroethene isomers

An intrinsically porous trianglimine macrocycle 1 is reported to display energy-efficient and cost-effective adsorptive properties by selectively separating cis-1,2-dichloroethene (cis-DCE) from an equimolar cis- and trans-DCE mixture with a purity of over 96%. The selectivity is enhanced by host/guest C-H⋯π intermolecular interactions. Moreover, the macrocycle can be reused many times without any decrease in performance, which further supports the sustainability of using molecular sieves in chemical separation.


Materials
All chemicals and solvents were purchased from commercial supplies and used without further purification.

Instrument and characterization
Nuclear magnetic resonance (NMR) 1 H NMR and 13 C NMR spectra were obtained on Bruker 400 MHz or 500 MHz spectrometers. Chemical shifts were reported in ppm relative to the residual solvent peak (CDCl 3 : 1 H, 7.26; 13 C, 77.23).

Thermogravimetric analysis (TGA)
TGA was carried out using an automatic sample loading TA instrument Q5000 analyzer. The samples were heated at the rate of 10 ℃/min using N 2 as the protective gas.

Single crystal X-ray diffraction (SCXRD)
SCXRD intensity data were collected using a Bruker D8 Venture with Photon II CPAD diffractometer (Mo Kα radiation, λ = 0.71073 Å) equipped with Incoatec IμS microfocus source, multilayer monochromator for the crystal structure. The crystal was collected at 120 K supported by Oxford Cryosystems 800 Plus cryostat. Data reductions were carried out by means of a standard procedure using the Bruker software package SAINT. S1 The absorption corrections and the correction of other systematic errors were performed using SADABS. S2 The structures were solved by direct methods using SHELXS-2008 and refined using SHELXL-2018.  was used as the graphical interface for the SHELX program suite. For all the cases non-hydrogen atoms were refined anisotropically. All other hydrogen atoms are geometrically fixed using riding atom model.

Gas chromatographic (GC)
GC measurements were carried out using an Agilent 7890A instrument configured with an FID detector and a DB-624 column (60 m × 0.25 mm × 1.4 m). The following GC method was used: the oven was programmed from 30 ℃ with a 2 min hold, ramped in 5 ℃/min increments to 100 ℃ with 2 min hold and further ramped 25 ℃/min increments to 150 ℃. The total run time was 20 min and the injection temperature was 250 ℃. Detection was performed using a single-quadrupole mass spectrometry in EI positive mode with a mass range of 35-300 m/z. The helium (carrier gas) flow rate was 1.0 mL/min. The samples were injected in the split mode (20:1).

Single crystal growth
Single crystals of 1A were obtained by the slow diffusion of methanol into a dichloromethane solution at room temperature. Single crystals of cis-DCE@ 1 were obtained by the slow diffusion of methanol into a cis-DCE solution at room temperature. Single crystals of trans-DCE@ 1 were obtained by the slow diffusion of methanol into a trans-DCE solution at room temperature.

Competitive crystallization
Macrocycle 1 was dissolved in an equimolar mixture of cis-and trans-DCE, then single crystals were obtained by vapor diffusion of methanol into the above solution at room temperature.

Adsorption material activation
Single crystals of 1A were dried under vacuum at 80 ℃ for 24 h to obtain the activated adsorptive materials (1 ). The 1 after adsorption could be regenerated to release the adsorbed guests upon heating at 100 ℃ under vacuum overnight.

Adsorption experiments for cis-or trans-DCE vapor.
An open 5 mL vial containing 20 mg of the 1 adsorbent was placed in a sealed 20 mL vial containing 1 mL of solvents (trans-DCE, cis-DCE, or an equimolar cis/trans-DCE mixture). The uptake capacity of 1 was measured at different time intervals by 1 H-NMR.

N 2 and CO 2 adsorption.
Low-pressure gas adsorption measurement was performed on a Micromeritics Accelerated Surface Area and Porosimetry System (ASAP) 2020 surface area analyzer. Samples were degassed under dynamic vacuum over night at 150 °C prior to each measurement. N 2 and CO 2 isotherms were measured using a liquid nitrogen (77 K) and water (298 K) baths respectively. Synthesis of trianglimine 1. Scheme S1. Synthetic scheme of macrocycle 1.