SELECTIVE FORMATION OF 4-MEMBERED METALLACYCLIC PT-N-P-C COMPOUNDS FROM REACTIONS OF BIS((N-ARYLIMINO)PHOSPHORANYL)METHANES WITH HALIDE-BRIDGED PLATINUM(II) PHOSPHINE DIMERS - X-RAY CRYSTAL-STRUCTURES OF [PTCL(PME(2)PH)(CH(PPH(2)=NC6H4-4-CH3)(PPH(2)NHC(6)H(4)-4-CH3))](+)CL- AND [PTCL(PET(3))(CH(PPH(2)=NC6H4-4-CH3)(PPH(2)NHC(6)H(4)-4-CH3))](+)[PTCL3(PET(3))](-)

Bridge-splitting reactions of Pt(2)X(4)(PR(3))(2) (X = Cl, Br; PR(3) = PEt(3), PMe(2)Ph) with bis(iminophosphoranyl)methanes CH2(PPh(2)=NC6H4-4-R')(2) (BIPM: 1a, R' = Me; 1b, R' = OMe) produced Pt(II) complexes, in which the BIPM ligand is N,C-coordinated: [PtX(PR(3)){CH-(PPh(2)=N-C6H4-4-R') (PPh(2)-NH-C6H4-4-R')}]Y-+(-) (2a-f, R' = CH3, OCH3, Y = Cl, Br, BF4, CF3CO2; 2g, R' = CH3, PR(3) = PEt(3), Y = PtCl(3)PEt(3)). In the N,C-coordinated BIPM, a net 1,3-H-shift from the bridging methylene group to the noncoordinated N-atom has taken place. NMR studies have revealed a monodentate sigma-N-coordinated species PtX(2)(PR(3)){N(C6H4-4-R')=PPh(2)CH(2)PPh(2)=NC6H4 A, as the first intermediate in the formation of 2. The complex formation is strongly dependent on the metal to ligand ratio, M:L. For M:L = 2:1, compound 2g(i) was formed, a N,N'-coordinated six-membered platinacycle, followed by conversion into the N,C chelate 2g, whereas at M:L = 1:2 two new products were obtained; a deprotonated Pt(II) complex with N,C-coordinated BIPM, [PtX(PR(3)){CH(PPh(2)=NC6H4-4-R')(2)] (3; X = Cl, PR(3) = PEt(3), R' = CH3), and the HCl salt of the ligand [HC(PPh(2)NHC(6)H(4)-4-R')(2)]Cl-+(-) (4). The molecular structures of [PtCl(PMe(2)Ph){CH(PPh(2)=NC6H4-4-CH3)(PPh(2)N'HC6H4-4-CH3)}](+)(Cl)(-) (2d) and [PtCl(PEt(3)){CH(PPh(2)=NC6H4-4-CH3)(PPh(2)N'HC6H4-4-CH3)}](+)(PtCl(3)PEt(3))(-) (2g) have been determined by X-ray crystallography. Crystal data for 2d: trigonal, space group P $($) over bar$$ 1, with a = 14.3852(11) Angstrom, b = 15.4886(9) Angstrom, c = 20.190(2) Angstrom, alpha = 100.580(7)degrees, beta = 92.223(8)degrees, gamma = 99.508(6)degrees, V = 4350.1(6) Angstrom(3), and Z = 4. Crystal data for 2g: trigonal, space group Pi, with a = 10.1970(8) Angstrom, b = 14.5045(9) Angstrom, c = 20.5471(19) Angstrom, alpha = 96.154(7)degrees, beta = 103.993(7)degrees, gamma 107.548(6)degrees, V = 2757.8(4) Angstrom(3), and Z = 2. The structure refinement converged to R(w) = 0.0432, R = 0.0436 for 2d and wR2 = 0.1247, R1 = 0.501 for 2g. The structure of the cationic parts of 2d and 2g comprises a distorted square planar Pt(II) environment, the coordination sites taken by PR(3), Cl, and the N and C atoms of the BIPM ligand. The structure of the anionic part of 2g, PtCl3(PEt(3)), is almost perfectly square-planar and is linked with the cationic part via a NH...Cl hydrogen bond.