The preparation and X-ray molecular structure of a novel dialkylpalladium(II) compound containing bridged thiophenoxymethyl groups

Abstract

A stable homoleptic palladium compound, [Pd(CH 2SC 6H 5) 2] 4 was isolated by treatment of (C 6H 5CN) 2PdCl 2 with LiCH 2SC 6H 5, and its molecular structure has been determined by means of three-dimensional X-ray diffraction data at −160°C. The CH 2Cl 2 solvate ([Pd(CH 2SC 6H 5) 2] 4 · CH 2Cl 2) forms orange-yellow, monoclinic crystals; a 16.302(3), b 19.394(4), c 18.552(3)Å and β 91.28(2)° at −160°C, space group P2 1/ n with Z = 4. The structure was solved by the conventional heavy atom method, and refined by the least-squares procedure to R = 0.089 for 4363 independent non-zero reflections. The fairly rigid cyclic tetramer is formed, which has approximate 222 symmetry. Four palladium atoms occupy the corners of a distorted rectangle and two averaged Pd···Pd distances are 4.051 and 3.304 Å, respectively. Four coordination planes around the palladium atom, the geometries of which are essentially square-planar, are equivalent with each other. The CH 2SC 6H 5 groups bridge four palladium atoms (mean SC(methylene) 1.82, SC(phenyl) 1.80 Å).