Role of Metals and Thiolate Ligands in the Structures and Electronic Properties of Group 5 Bimetallic-Thiolate Complexes.

Syntheses, structures, and electronic properties of group 5 metal-thiolate complexes that exhibit unusual coordination modes of thiolate ligands have been established. Room-temperature reaction of [CpVCl] (Cp = η-CMe) with Na[B(SCHS)] led to the formation of [CpVO{(SCH)S}] (). The solid-state X-ray structure of shows the formation of six-membered l,3,5-trithia-2-vanadacyclohexane that adopted a chair conformation. In a similar fashion, reactions of heavier group 5 precursors [CpMCl] (M = Nb or Ta) with Na[B(SCHS)] yielded bimetallic thiolate complexes [(CpM)(μ-S){μ-C(H)S-κ:κ',″}{μ-SC(H)S-κ:κ‴,''''}] (: M = Nb and : M = Ta). One of the key features of molecules and is the presence of square-pyramidal carbon, which is quite unusual. The reactions also yielded bimetallic methanedithiolate complexes [(CpNb)(μ-S)(μ-SCHS-κ,')(μ,η:η-BHS)] () and [(CpTa)(μ-O)(μ-SCHS-κ,')(μ-H){μ-SC(H)SCHS-κ″:κ‴,''''}] (). Complex contains a methanedithiolate ligand that stabilizes the unsaturated niobaborane species. On the other hand, one ((mercaptomethyl)thio)methanedithiolate ligand {CHS} is present in , which is coordinated to metal centers and exhibits the {μ-κ″:κ‴,''''} bonding mode. Along with the formation of and , the reaction of [CpTaCl] with Na[B(SCHS)] yielded [(Cp*Ta)(μ-S){μ-(SBS)S(CHS)(BHS)-κ:κ:κ',″,‴,''''}] () containing a trithiaborate unit (BS). Complex consists of pentacoordinate boron that resides in a square-pyramidal environment. All the complexes have been characterized by multinuclear NMR, UV-vis spectroscopy, mass spectrometry, and single-crystal X-ray diffraction studies.