Crystallographic evidence for the coordination performance of WO 2S 22−. : Synthesis, characterization and crystal structure of palladium complexes with mixed-ligand thiotungstates and 1,2-dithiolates: [NBu 4] 2[PdWO 2S 2(C 3S 5)] and [NBu 4] 2[PdWS 4(C 4N 2S 2)

Abstract

Two novel palladium complexes derived from thiotungstates and 1,2-dithiolates, [NBu 4] 2[PdWO 2S 2(dmit)] ( 1) and [NBu 4] 2[PdWS 4(mnt)] ( 2) (H 2dmit = 4,5-dimercapto-1,3-dithiole-2-thione, H 2mnt = 2,3-dimercapto-2-butenedinitrile), have been synthesized and characterized. X-ray diffraction analyses reveal that palladium in 1 is coordinated by a dmit (C 3S 5 2−) and a dioxothiotungstate (WO 2S 2 2−), whilst in 2 it is coordinated by a mnt (C 4N 2S 2 2−) and a tetrathiotungstate (WS 4 2−). 1 is the first structurally determined metal complex with dioxothiotungstate as ligand. Both dithiolates and thiotungstates in 1 and 2 play the role of bidentate ligands through two sulfur atoms chelating palladium atoms. The Pd–W distances are 2.917(1) and 2.896(1) Å in 1 and 2, respectively. The electronic properties have been investigated by spectroscopic techniques and cyclic voltammetry. The reaction of 2 with Ag(Ph 3P) 2NO 3 affords Pd(Ph 3P) 2(mnt) and Ag 4W 2S 8(Ph 3P) 4.