An Alkynyl-Stabilized Pt5 Ag22 Cluster Featuring a Two-Dimensional Alkynyl-Platinum "Crucifix Motif".

The "staple motif" has been widely applied to depict and predict the structures of thiolate or alkynyl-protected gold nanoclusters. By contrast, the composition, dimensions, configuration, and functionality of the platinum-ligand motif has remained completely unknown. Herein, we report the synthesis and crystal structure of a novel luminescent Pt5 Ag22 (C≡CPh)32 (1) cluster, in which two-dimensional and two-functional alkynyl-platinum "crucifix motif" was observed. Such a crucifix motif with one Pt center and four alkynyl groups in the same plane acts as a two-dimensional unit in the cluster and functions as both a protective cover and an intermediate joint.