A ladder polysilane as a template for folding palladium nanosheets

Abstract

Although discrete nano-sized compounds consisting of a monolayer sheet of multiple atoms have attracted much attention, monolayer transition metal nanosheets are difficult to access. Here we report a template synthesis of the folding metal nanosheet (2) consisting of 11 palladium atoms by treatment of a ladder polysilane, decaisopropylbicyclo[2.2.0]hexasilane (1), with Pd(CN t Bu) 2. Crystallographic analysis reveals that the compound is composed of two monolayer Pd 7 sheets sharing three palladium atoms at the junction. Each Pd atom is stabilized by Pd-Si σ-bonds, Pd-Pd bonds and coordination of isocyanides. Ligand exchange of 2 from CN t Bu to CN(2,4,6-Me 3 -C 6 H 2) is accompanied by structural rearrangement, leading to the formation of another folding Pd 11 nanosheet (3) consisting of two edge-sharing Pd 7 sheets. The shapes of the Pd 7 sheets as well as the dihedral angle between the two Pd 7 sheets are dependent on the substituent of the isocyanide ligand. © 2013 Macmillan Publishers Limited. All rights reserved.