FORMATION OF A FORMAL DIPHOSPHINE MONOCATION AND DICATION FROM "(METHYLAMINO)BIS(DIFLUOROPHOSPHINE)

The reactions of (methylamino)bis(difluorophosphine), CH3N(PF2)2, with the strong transition-metal nucleophile NaMo(π-C5H5)(CO)3 in 1: 1 and 1: 2 mole ratios in THF solution produce new species with compositions described by the formulas F2PN(CH3)PFMoCp(CO)3 and F2PN(CH3)PMo2Cp2(CO)4, respectively. The new compounds have been characterized by chemical analyses, solution conductance, and mass, infrared, and 1H, l3C, 19F, and 31P NMR spectrometry techniques. The data show that the diphosphine ligand in each compound contains a unique phosphorus atomin a highly deshielded electronic environment: P in F2PN(CH3)PMo2Cp2(CO)4 has the lowest 31P shift yet reported in a phosphine ligand. Structures for the new compounds containing formal cationic diphosphine ligands are proposed. © 1979, American Chemical Society. All rights reserved.