TETRAKIS(ORGANODIFLUOROPHOSPHINE)PLATINUM(0) AND BIS(ARYLPHOSPHONOFLUORIDITE)-BIS(ARYLPHOSPHONOFLUORIDOUS ACID)-PLATINUM(II) COMPLEXES

The reaction of potassium tetrachloroplatinate(II) with tert-butyldifluorophosphine, phenyldifluorophosphine, and 2,5-dimethylphenyldifluorophosphine under mild conditions led to the formation of tetrakis(organodifluorophosphine)platinum(0) complexes. A combined partial hydrolysis and oxidation reaction of the tetrakis(aryldifluorophosphine)platinum(0) complexes furnished bis(arylphosphonofluoridite)-bis(arylphosphonofluoridous acid)platinum(II) complexes. The reaction of bis(2,5-dimethyl-phenylphosphonofluoridite)-bis(2,5-dimethylphenylphosphonofluoridous acid)platinum(II), 7, with boron trifluoride produced bis[2,5-dimethylphenylphosphonofluoridite)difluoroborato]platinum(II), 9. The controlled hydrolysis of the difluorophosphine, 2,6-(PhO)2C6H3PF2, 10, led to the corresponding phosphonofluoridous acid, 2,6-(PhO)2C6H3P(:O)(H)(F), 11. The structure and identity of the products are described, based on their H-1, C-13, F-19 and P-13 n.m.r. spectra and on their mass spectra. The presumed mode of formation of the platinum(0) and platinum(II) complexes is discussed. A single crystal X-ray diffraction study was conducted on the complex, meso-bis(2,5-dimethylphenylphosphonofluoridite)-bis(2,5-dimethylphenylphosphonofluoridous acid)platinum(II), 7. Strong intramolecular hydrogen bonding was reflected in an O - H - O distance of 235 ppm. The crystal structure of the product, 9, of the reaction of 7 with boron trifluoride etherate was also studied. The molecule of 9 possesses crystallographic inversion symmetry and thus a meso configuration, as does the precursor compound, 7. The PtP2O2B six-membered ring displays a distorted boat conformation. The coordination geometry at platinum is almost exactly square planar, with normal Pt - P bond lengths of 231.1 and 231.4 pm. The X-ray crystal structure determination of the phosphonofluoridous acid, 11, proved that the compound is present as the phosphoryl tautomer, involving lambda-4-phosphorus, with a direct P - H bond in the solid state.