New platinum(II) complexes of Ph(2)PNHP(O)Ph(2) and [Ph(2)PNP(O)Ph(2)]

Refluxing a suspension of cis-[PtCl2(HL)(2)][HL = Ph(2)PNHP(O)Ph(2)-P] in methanol for ca. 11 h led to Ph(2)P-N bond clevage of one of the HL ligands and formation of cis-[PtCl2(HL)(Ph(2)POMe)] 1. Prolonged refluxing of 1 in methanol (5 d) gave predominantly unchanged 1 in addition to some cis-[PtCl2(Ph(2)POMe)(2)] 2 and cis-[PtCl(L)(Ph(2)POMe)] 3 [L = Ph(2)PNP(O)Ph(2)-P,0]. Reaction of 1 with KOBu(t) afforded solely 3 in good yield. Bridge clevage of [{PtCl(mu-Cl)(PMe(2)Ph)}(2)] with 2 equivalents of HL gave trans-[PtCl2(HL)(PMe(2)Ph)] 4a which is smoothly isomerised to cis-[PtCl2(HL)(PMe(2)Ph)] 4b upon addition of trace amounts of HL. Complexes 4a and 4b reacted with KOBu(t) (ca. 1.4 equivalents) in methanol to yield trans- and cis-[PtCl(L)(PMe(2)Ph)] 5a and 5b respectively. Chloride abstraction of either 4a and 4b with Ag[BF4] in dichloromethane yielded the P,0-chelate cationic complexes trans-(6a) or cis-[PtCl(HL)(PMe(2)Ph)][BF4] 6b respectively. Further reaction of 5b with KOBu(t) in methanol gave the hydroxide-bridged platinum(II) dimer [{Pt(mu-OH)L(PMe(2)Ph)}(2)] 7 in which the P-donor atom in L is co-ordinated to the platinum(II) centre and the O-donor atom is involved in an intramolecular hydrogen bond to the hydroxide ligand (X-ray evidence). All the compounds 1-7 have been characterised by a combination of P-31-{H-1} and Pt-195-{H-1} NMR, IR spectroscopy and microanalysis. Furthermore the solid-state structures of cis-[PtCl2(HL)(PMe(2)Ph)], the geometric isomers trans- and cis-[PtCl(L)(PMe(2)Ph)] and [{Pt(mu-OH)L(PMe(2)Ph)}(2)] have been determined by single-crystal X-ray diffraction.