NEW DINUCLEAR MOLYBDENUM(0)-SR COMPOUND CONTAINING A BUTTERFLY TYPE MOS2MO CORE - SYNTHESIS, STRUCTURE AND CYCLIC VOLTAMMETRY OF DI-(O-METHYLPHENTHIOLATO)DIMOLYBDENUM(0) OCTACARBONYL DIANION, [MO-2(O-CH3-C6H4-S)(2)(CO)(8)](2-)

Reaction of molybdenum hexacarbonyl with o-methyl-thiophenolate in MeC N afforded a new dinculear Mo-0-SR compound, [Et(4)N](2)[Mo-2(o-CH3-C6 H4-S)(2)(CO)(8)] (1). Compound 1 . MeCN was characterized by single-cr ystal X-ray structure determination and its electrochemical behaviour was measured by cyclic voltammetry. The anion of 1 contains a ''butter fly'' type bimetallic MoS2Mo core with an Mo-Mo distance of 3.942(3) A ngstrom, Mo-S of 2.622 Angstrom, S-Mo-S of 77.3 degrees and Mo-S-Mo of 97.54 degrees, and exhibits very different electrochemical behaviour from its analogues, [Mo-2(o-OH-C6H4-S)(2)(CO)(8)](2-) (2), [Mo-2(C6H5S )(2)(CO)(8)](2-) (3) with a planar MoS2Mo core and [Mo-2(S,S-C6H-1,2)( 2)(CO)(8)](2-) (4) with a core which consists of a non-planar MoS2Mo u nit and a bridging carbonyl. Considering 1-4 together, the synthesis, influence of steric hindrance of ligands on MoS2Mo core configuration and thus on the electrochemical behaviour were discussed. Copyright (C ) 1996 Elsevier Science Ltd