The stability enhancement factor beyond eight-electron shell closure in thiacalix[4]arene-protected silver clustersElectronic supplementary information (ESI) available. CCDC 1863292 and 1863293. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8sc03756f

• Main Authors: Guan, Zong-Jie, Hu, Feng, Yuan, Shang-Fu, Nan, Zi-Ang, Lin, Yu-Mei, Wang, Quan-Ming
• Format: Journal Article
• Language: English
• Published: 13.03.2019
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c8sc03756f

We report the synthesis and structures of two 34-atom metal nanoclusters, namely [Ag 34 (BTCA) 3 (C&z.tbd;CBu t ) 9 (tfa) 4 (CH 3 OH) 3 ]SbF 6 and [AuAg 33 (BTCA) 3 (C&z.tbd;CBu t ) 9 (tfa) 4 (CH 3 OH) 3 ]SbF 6 , where H 4 BTCA is p-tert -butylthiacalix[4]arene and tfa is trifluoroacetate. Their compositions and structures have been determined by single-crystal X-ray structural analysis and ESI-MS. The cationic cluster consists of a centered icosahedron M@Ag 12 (M = Ag or Au) core that is surrounded by 21 peripheral silver atoms. Surrounding protection is provided by four kinds of ligands, including three BTCA, nine t BuC&z.tbd;C, four tfa, and three methanol solvent ligands. It was found that the Ag 5 @BTCA μ 5 -coordination motif of thiacalixarene is critical for high stability of the title clusters, and extra stability enhancement can be achieved by doping a gold atom at the center of the silver cluster. This work suggests that coordination saturation should be taken into account in addition to electronic and geometric factors for analyzing metal nanocluster stabilities. Destroying coordination open sites may significantly enhance the stability of metal nanoclusters.