Synthesis and characterization of low valent vanadium thiolate complexes

The reaction of the bulky lithium terphenyl thiolate LiSAr′ (Ar′=C6H3-2,6-(C6H3-2,6-Pr2i)2) with VI2(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 VI2(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 η6-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 VI2(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.

The addition of one or two equivalents of a lithium terphenyl thiolate (LiSAr′,Ar′=C6H3-2,6(C6H3-2,6-Pr2i)2) to VI2(thf)4 afforded the V(II) and V(III) thiolates [V(μ-SAr′)I]2 and [V(SAr′)2I].Figure optionsDownload as PowerPoint slide