Group 6 metallocene(IV)–main group metal complexes: synthesis and structures of a Mo–B–Li compound and of [W(η-C5H5)2H{SnCl2CH(SiMe3)2}]

Abstract

The reaction between [{Mo(η-C₅H₅)₂H(µ-Li)}₄]Ia, B(C₆H₂Bu^t₃-2,4,6)Cl₂ and Me₂NCH₂CH₂NMe₂(tmen) afforded the crystalline complex [Mo(η-C₅H₅)H₂{(C₅H₄)[graphic omitted]H₂-2)}{Li(tmen)}]1, having single hydrido bridges between Li and Mo (H_a) and Li and B (H_c). A single-crystal structure analysis gave the bond distances Mo–H_a 1.66(5), Mo–H_b 1.44(6), Li–H_a 1.67(6), Li–H_c 1.90(6), B–H_c 1.21(5), Mo ⋯ Li 3.08(1) and Li ⋯ B 2.63(1)Å. Detailed multinuclear NMR spectroscopic data for 1 showed that the same structure was retained in [²H₈] toluene solution. From Ib(the tungsten equivalent of Ia) and SnX₂R′₂[R′= CH(SiMe₃)₂′ X = F or Cl] or SnCl₃R′(prepared from SnCl₄ and LiR′) the new W–Sn complexes [W(η-C₅H₅)H(Y)][Y = SnCl₂R′2, SnCl(Me)R′, SnFR′₂ or SnClR′₂] were prepared and characterised. A single-crystal structure determination of 2 gave W–Sn 2.706(1), Sn–C 2.180(8) and average Sn–Cl 2.423(3)Å.