Synthesis and characterization of low valent vanadium thiolate complexes

Abstract

The reaction of the bulky lithium terphenyl thiolate LiSAr′ ( Ar ′ = C 6 H 3 - 2 , 6 - ( C 6 H 3 - 2 , 6 -Pr 2 i ) 2 ) with VI 2(THF) 2 in THF resulted in the formation of two new V(II) and V(III) thiolate complexes. The addition of one equivalent of LiSAr′ to VI 2(THF) 4 led to the isolation of the dimeric V(II) species {V(μ-SAr′)I} 2 ( 2); a rare example of a structurally characterized V(II) thiolate. The thiolate ligands bridge the two vanadium centers, which are also bonded to a terminal iodide. In addition, there is an η 6-interaction between a flanking aryl ring from a terphenyl substituent with each metal. The attempted preparation of the vanadium dithiolate V(SAr′) 2 by reaction of VI 2(THF) 2 with two equivalents of LiSAr′ led to disproportionation which resulted in the isolation of the V(III) product V(SAr′) 2I ( 3) in which the vanadium center is coordinated by two sulfurs, an iodine, and a weaker interaction to a flanking aryl ring of the terphenyl group.