title: Ligand-exchange synthesis of selenophenolate-capped Au25 nanoclusters.
abstract: We report the synthesis and characterization of selenophenolate-capped 25-gold-atom nanoclusters via a ligand-exchange approach. In this method, phenylethanethiolate (PhCH(2)CH(2)S) capped Au(25) nanoclusters are utilized as the starting material, which is subject to ligand-exchange with selenophenol (PhSeH). The as-obtained cluster product is confirmed to be selenophenolate-protected Au(25) nanoclusters through characterization by electrospray ionization (ESI) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), thermogravimetric analysis (TGA), elemental analysis (EA), UV-Vis and (1)H/(13)C NMR spectroscopies. The ligand-exchange synthesis of [Au(25)(SePh)(18)](-)[(C(8)H(17))(4)N](+) nanoclusters demonstrates that the core size of gold nanoclusters is retained in the thiolate-to-selenolate exchange process and that the 18 surface thiolate ligands can be completely exchanged by selenophenolate, rather than giving rise to a mixed ligand shell on the cluster. The two types of Au(25)L(18) (L = thiolate or selenolate) nanoclusters also show some differences in stability and optical properties.
authors.affiliation: Department of Chemistry, Anhui University, Hefei, Anhui 230026, P. R. China.
authors.forename: Xiangming
authors.initials: X
authors.lastname: Meng
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Shuxin
authors.initials: S
authors.lastname: Wang
authors.forename: Manzhou
authors.initials: M
authors.lastname: Zhu