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

摘要

Reaction of [Mn(CO)_5X] (X = Cl or Br) with L-L {L-L = dppm (Ph_2PCH_2PPh_2), dppe (Ph_2PCH_2CH_2PPh_2), dppp (Ph_2PCH_2CH_2CH_2PPh_2), C_6H_4(PPh_2)_2-o, C_6H_4(PPh_2)_2-o, dpae (Ph_2AsCH_2CH_2AsPh_2), diars [C_6H_4(AsMe_2)_2-o], dpsp (Ph_2SbCH_2CH_2CH_2SbPh_2) or dmsp (Me_2SbCH_2CH_2CH_2SbMe_2)} or with two molar equivalents of L (=PPh_2H, PCy_2H or PPhH_2) in refluxing CHCl_3 yielded the neutral manganese (I) complexes [MnX(CO)_3(L-L)] and [MnX(CO)_3L_2] as yellow or orange solids. Infrared spectroscopic studies confirmed the fac-tricarbonyl arrangement and ~1H, ~(13)C-{~1H}, ~(31)P-{~1H} and ~(55)Mn NMR spectroscopy have been used to probe the solution behaviour, For a given halide ~(55)Mn NMR spectroscopic studies showed some dependence of #delta#(~(55)Mn) on halide, chelate ring size, substituent and donor atom. X-Ray crystallographinc analyses on [MnCl(CO)_3{C_6H_4(PPh_2)_2-o}], [MnBr(CO)_3 (dppe)] and the diprimary phosphine complex [MnCl(CO)_3{C_6H_4(PPh_2)_2-o}] centre dot CH_2Cl_2 confirmed a fac-tricarbonyl arrangement, with the ditertiary or diprimary phosphine chelating. The structure of [MnBr(CO)_3(PPhH_2)_2] also shows a fac-tricarbonyl arrangement with the primary phosphine ligands mutually cis.