SYNTHESIS AND CHARACTERIZATION OF NEW HOMO-HETEROBINUCLEAR PLATINUM(II) COMPLEXES WITH DIMETHYLPHOSPHONATE AS BRIDGING LIGANDS - CRYSTAL-STRUCTURE OF [(ETA(2)DPPM)PT(MU-P(O)(OME)(2))(2)(MU-I)PTME(3)]

The preparation of the new neutral complex [(eta(2)-dppm)Pt{P(O)(OMe)( 2)}(2)] (1) (dppm = 1,1-bis(diphenylphosphino) methane) and its behavi our as a chelate (O,O)-donor ligand is described. This ligand reacts w ith [Me(3)PtI](4) to give the homobimetallic complex [(eta(2)dppm)Pt{m u-P(O)(OMe)(2)}(2)(mu-I)PtMe(3)] (2), which in turn reacts with AgPF6 in the presence of PPh(3) to yield the new cationic complex 2)dppm)Pt{ mu-P(O)(OMe)(2)}(2){PtMe(3)(PPh(3))}]PF6 (3). In contrast, the treatme nt of binuclear complexes [{Pd(mu-Cl)(2-MeC(3)H(4))}(2)] and [{Rh(mu-C l)(cod)}(2)] with silver perchlorate in the presence of the bidentate ligand 1 yields the heterobinuclear compounds ppm)Pt{mu-P(O)(OMe)(2)}P d-2(eta(3)MeC(3)H(4))]ClO4 (4) and [(eta(2)dppm)Pt{mu-P(O)(OMe)(2)}Rh- 2(cod)]ClO4 (5). Complex 5 reacts with an atmosphere of CO at room tem perature yielding the cis-dicarbonyl complex [(eta(2)dppm)Pt{mu-P(O)(O Me)(2)}Rh-2(CO)(2)]ClO4 (6). The structure of complex [(eta(2)dppm)Pt{ mu-P(O)(OMe)(2)}(2)(mu-I)PtMe(3)] has been determined by single crysta l X-ray diffraction methods.