Multinuclear NMR studies of diphosphine, diphosphine-dioxide and diarsine complexes of tin(IV) halides. Structures of [SnI_4{o-C_6H_4(AsMe_2)_2}] and [SnI_4{o-C_6H_4(P(O)Ph_2)_2}]

摘要

The complexes [SnX_4(L-L)] (X = Cl or Br, L-L = Me_2PCH_2CH_2PMe_2, Ph_2PCH_2CH_2PPh_2, o-C_6H_4(PPh_2)_2, o-C_6H_4(AsMe_2)_2, Ph_2AsCH_2CH_2AsPh_2) have been isolated from reaction of SnX_4 with the ligand in anhydrous CH_2Cl_2. The complexes have been characterised by analysis, IR and multinuclear NMR (~1H, ~(31)P and ~(119)Sn) spectroscopy. Rare examples of complexes with SnI_4 have been isolated with all the above ligands except Ph_2AsCH_2CH_2AsPh_2 and similarly characterised. The multinuclear NMR studies reveal reversible ligand dissociation in some of the chloro- and bromo-complexes in solution, the extent varying with the neutral ligand involved, but all the iodo-complexes are extensively dissociated in solution. Complexes of PMe_3 and the diphosphide-dioxide o-C_6H_4(Ph_2PO)_2 are also described. X-ray structures of [SnI_4{o-C_6H_4(AsMe_2)_2}] and of [SnI_4{o-C_6H_4(Ph_2PO)_2}] and its CH_2Cl_2 solvate are reported.