Mono-and di-bridged heterobimetallic systems from group 5 hydride phosphido and hydride phosphino metalloligands. Crystal structure of Cp2Ta(H)(μ-H)(μ-PMe2)Cr(CO)4

Article abstract of DOI:10.1016/S0022-328X(97)00219-2

The trihydrides Cp₂MH₃ (M = Nb, Ta) react with chlorophosphines PR₂Cl (R = Me, Ph) affording phosphonium salts [Cp₂MH₂(PR₂H)]⁺, Cl^- (2 (a, b) 2′ (a, b)). Depending on the metal (Nb or Ta) and on the nature of the phosphine substituent (Me or Ph), deprotonation of these salts leads to hydride phosphino Cp₂MH(PR₂H) (3 (a, b) 3′a) or hydride phosphido Cp₂TaH₂(PPh₂) (4′b) metalloligands. These two kinds of complexes are able to bind [M′(CO)₅] or [M′(CO)₄] (M′ = Cr, Mo, W) organometallic fragments to give mono-or di-bridged heterobimetallic systems. The crystallographic analysis of Cp₂Ta(H)(μ-H)(μ-PMe₂)Cr(CO)₄ (7′aCr) is reported and discussed.