A New Class of Tantalum(V) Dithiolate Complexes: Synthesis and Characterization of [Ta(η⁵‐C₅Me₄R)(SCHCHS)₂] (R = Me, Et) and [Ta(η⁵‐C₅Me₅)(SCH₂CH₂S)₂]

Abstract

Angew. Chem. In!. Ed. Engl. 24 (1985) No. 4 0 YCH Verlugsgesellschu~ mbH. 0-6940 Weinheim, 1988 0870-0833/85/0404-0333 $ 02.50/0

Diene complexes of early transition metals: ideas and progresses at Osaka University

“…Our approach has been based on the coordination space of half-metallocene fragments of niobium and tantalum, in which various catalytic and stoichiometric transformations have been performed. Tatsumi prepared bis(1,4-dithia-1,3-butadiene) complex, Cp*Ta(SCH@CHS) 2 (39), that adopts supineprone orientation [99]. The unique C-S bond fission of 39 led to the chemistry of the sulfide complexes such as [Cp*Ta(S) 3 ] 2À (40) [100], and since then he has been extending this line of the chemistry.…”

Niobium and Tantalum

“…For example, the dithiolate compounds of Ta v Cp*Ta(SCH=CHS) 2 , (r|-C 5 Me 4 Et)-Ta(SCH=CHS) 2 , and Cp*Ta(SCH 2 CH 2 S) 2 are prepared by reacting Cp*TaCl 4 or (t|-C 5 Me 4 Et)TaCl 4 with Na 2 S 2 C 2 H 2 (THF, -10 °C), and from Cp*TaCl 4 with Na 2 S 2 C 2 H 4 (CH 2 C1 2 , room temperature). 514 Cp*Ta(SCH=CHS) 2 shows the existence of two conformers in solution.…”

Synthesis and characterisation of monocyclopentadienyl dithiolato complexes of niobium and tantalum; crystal structures of [Nb2(μ-O)(μ-η2∶η2-S2C2H4)(η5-C5H4Me)2Cl4] and [Nb2(μ-η1∶η2-S2C2H4)2(η5-C5H4Me)2O(S2C2H4)] †

“…These findings reflect those for related anionic titanium complexes in solution, 6 but it is notable that variable temperature NMR spectra of [TaCp*(SCH᎐ ᎐ CHS) 2 ] support the presence of interchanging exo and endo ethene-1,2dithiolate ligands. 7 A basic four-legged piano stool geometry can be assumed for these products but crystals suitable for X-ray diffraction could not be obtained so that the conformations of the thiolate ligands in the solid state conformations were not determined. The IR spectra include bands character-istic of the cyclopentadienyl and aromatic ligands, and the electronic spectra contain strong bands in the visible region, e.g.…”