| Single-crystal X-ray diffraction, S@Cu₁₄-4MBT | Triclinic crystal system; P–1 space group; a = 19.1904(11) Å, b = 19.3952(12) Å, c = 35.023(2) Å, α = 105.541(2)°, β = 90.134(2)°, γ = 119.002(2)°, V = 10848.04(110) ų, Z = 2 |
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| Single-crystal X-ray diffraction, S@Cu₁₄-3MBT | Trigonal crystal system; R–3 space group; a = 18.8787(12) Å, c = 47.429(5) Å, V = 14639.25(200) ų, Z = 3; c/a = 2.5123 |
| Single-crystal X-ray diffraction, shared S@Cu₁₄ architecture | Central S²⁻ anion coordinated to eight Cu(I) atoms in a distorted Cu₈ cube; Cu···Cu distances 3.025–3.328 Å; average bridging-thiolate Cu–S distance 2.269 Å; average surface-Cu Cu–S distance 2.271 Å; average Cu–P distance 2.216 Å |
| Single-crystal X-ray diffraction, crystal packing | S@Cu₁₄-4MBT adopted ABA-type stacking; S@Cu₁₄-3MBT adopted ABCA-type stacking and had C–H···π distances within 3.778 Å |
| X-ray photoelectron spectroscopy, survey spectra | Signals corresponding to Cu, S, P, and C |
| Cu 2p X-ray photoelectron spectroscopy | Cu species in both nanoclusters predominantly assigned to Cu(I); no obvious shake-up satellite peaks associated with Cu(II); S@Cu₁₄-3MBT peaks at slightly higher binding energies than S@Cu₁₄-4MBT |
| Solid-state diffuse-reflectance spectroscopy | Optical band gap 2.910 eV for S@Cu₁₄-4MBT and 2.864 eV for S@Cu₁₄-3MBT |
Yihan Chen, Mandira Ghosh, Mohd Rashid, Maho Kamiyama, Sahla Sherin, Shahina M K, Tokuhisa Kawawaki, Biswarup Pathak, Sourav Biswas, Yuichi Negishi. “Anion-templated Cu₁₄ nanoclusters reveal ligand-controlled stability and catalytic evolution during electrochemical CO₂ reduction.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007715/v1
Values presented only in analytical plots and molecular-structure images were not transcribed. The main paper refers to supporting information, but no separate supporting information file was found among the files available from the ChemRxiv record
| Cu 2p X-ray photoelectron spectroscopy | Pronounced satellite feature for S@Cu₁₄-4MBT_AC; feature absent for S@Cu₁₄-3MBT_AC |
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| S 2p X-ray photoelectron spectroscopy | Additional peaks at higher binding energies for S@Cu₁₄-4MBT_AC, assigned to free thiolate ligands due to ligand detachment during electrolysis |
| Cu K-edge XANES and FT-XAFS, S@Cu₁₄-3MBT before and after catalysis | Nearly identical spectra; unchanged coordination peak at ~1.8 Å |