Isomer-Selective Conversion of Au Clusters by Au(I) Thiolate Insertion.

Isomer-selective conversion is a challenging goal in the rational design of Au clusters. Herein, we demonstrate the isomer-selective conversion of Au(SC) (SC = cyclohexanethiolate) into Au(SR)(SC) in high yields by reactions with gold(I) thiolate (AuSR) complexes. Electrospray ionization mass spectrometry indicated that even numbers of AuSR units are inserted into Au(SR)(SC) to generate Au(SR)(SC) through intermediates Au(SR)(SC) or Au(SR)(SC). These results suggest that the number of constituent atoms in surface Au(I)SR oligomers only increases, while the number of electrons in an Au core is maintained. UV-vis analysis revealed the generation of one of two Au(SR)(SC) isomers in the reactions of Au(SC) with AuSR complexes, in contrast to the formation of both isomers by reactions with thiols. When the structures of Au(SR) are compared with those of the Au(SR) isomers, the partial structure in the Au cores is preserved in the isomer-selective conversion with AuSR complexes, regardless of the structures of the thiolate moiety.