Phosphine, arsine and stibine complexes of manganese(I) carbonyl halides: synthesis, multinuclear NMR spectroscopic studies, redox properties and crystal structures

Reaction of[Mn(CO)(5)X] (X = Cl or Br) with L-L (L-L = dppm (Ph2PCH2PPh2), dppe (Ph2PCH2CH2PPh2), dppp (Ph2PCH2CH2CH2PPh2), C6H4(PPh2)(2)-o, C6H4(PH2) (2)-o, dpae (Ph2AsCH2CH2AsPh2), diars [C6H4(AsMe2)(2)-o], dpsp (Ph2SbCH2CH2 CH2SbPh2) or dmsp (Me2SbCH2CH2CH2SbMe2)) or with two molar equivalents of L (= PPh2H, PCy2H or PPhH2) in refluxing CHCl3 yielded the neutral manganese (I) complexes [MnX(CO)(3)(L-L)] and [MnX(CO)(3)L-2] as yellow or orange sol ids. Infrared spectroscopic studies confirmed the fac-tricarbonyl arrangeme nt and H-1,C-13-(H-1), P-31-(H-1) and Mn-55 NMR spectroscopy have, been use d to probe the solution behaviour. For a given halide Mn-55 NMR spectroscop ic studies showed some dependence of delta(Mn-55) on halide, chelate ring s ize, substituent and donor atom. X-Ray crystallographic analyses on [MnCl(C O)(3)(C6H4(PPh2)(2)-o)], [MnBr(CO)(3)(dppe)] and the diprimary phosphine co mplex [MnCl(CO)(3)(C6H4(PH2)-o)]. CH2CI2 confirmed a fac-tricarbonyl arrang ement, with the ditertiary or diprimary phosphine chelating. The structure of [MnBr(CO)(3)(PPhH2)(2)] also shows a fac-tricarbonyl arrangement with th e primary phosphine ligands mutually cis.