Core-Size Conversion of Au₃₈(SCH₂CH₂Ph)₂₄ to Au₃₀(S–<i>t</i>Bu)₁₈ Nanomolecules

Abstract

Au 38 (SCH 2 CH 2 Ph) 24 nanomolecules upon etching with tert -butylthiol undergo core-size conversion to green-gold Au 30 (S– t Bu) 18 via Au 36 (SCH 2 CH 2 Ph) 24- x (S– t Bu) x intermediate. The structural transformation from Au 38 to Au 30 indicates a strong steric effect due to the tert -butyl group of the exchanging ligand in contrast to electronic effect by ligands such as thiophenol, which transforms the Au 38 (SCH 2 CH 2 Ph) 24 to Au 36 (S– t Bu) 24 . In this work, fast reaction kinetics were observed and thermodynamically stable Au 30 (S– t Bu) 18 was obtained in molecular purity.