Preparation and structure of a compound containing a triply bridged binuclear Mo(V) cation and the [MoOCl 4(H 2O)] − anion

Abstract

The reaction of di-μ-oxo-bis[oxo-N,N-diethyldithiocarbamatomolybdenum(V)], Mo 2O 4(S 2CNEt 2) 2, with thiophenol produces a red-orange diamagnetic compound which contains thiophenol and diethyldithiocarbamate in a 1:1 ratio. The attempted recrystallisation of this material from CHCl 3/CCl 2 in the presence of excess thiophenol resulted in an unexpected chemical reaction and the formation of green crystals shown to be [Mo 2O 2 —(SPh) 2Cl(S 2CNEt 2) 2] + [MoOCl 2(H 2O)]-CHCl 3 by a single-crystal X-ray structure determination and by supporting physical data. The μ-chloro-di-μ-thiophenolatobis [oxo-N,N-diethyldithiocarbamatomolybdenum(V)] cation contains two [MoO] 3+ units which are triply bridged by the S atoms from the two SPh ligands and by the Cl atom. The bridging Cl atom is approximately trans to the terminal O atoms of each Mo. A diethyldithiocarbamato ligand completes the distorted six-coordinate geometry about each Mo. The effective symmetry of the cation is nearly C 2v and the Mo…Mo distance is 2.822(2) Å. The monomeric oxo-tetrachloroaquomolybdate(V) anion, [MoOCl 4(H 2O)]-, has approximate C 4v symmetry with Mo−O t = 1.641(7) A ̊ , Mo−Cl = 2.344(2) − 2.396(4) A ̊ and Mo−OH 2 = 2.342(8) A ̊ . The compound has a magnetic moment consistent with the presence of one unpaired electron per formula unit.