PLATINUM RHODIUM A-FRAME AND DOUBLE A-FRAME COMPLEXES BRIDGED BY BIS(DIPHENYLPHOSPHINO)METHANE LIGANDS

The organoplatinum compounds [PtR(dppm-PP))(dppm-P)]PF6 (R = Me, Et, P h) react with [Rh-2(mu-Cl)(2)(cod)(2)] in the presence of carbon monox ide to yield the double A-frame complexes [RPt(mu-Cl)(mu-CO)(mu-dppm)( 2)Rh(CO)]PF6 These lose CO reversibly to give the corresponding A-fram e species [RPt(mu-Cl)(mu-dppm)(2)Rh(CO)]PF6. The products have been ch aracterized by NMR and IR spectroscopies, the double A-frames exhibiti ng C-13 resonances around 200 ppm, which show couplings to both platin um and rhodium, and nu(CO) bands in the range 1855-1864 cm(-1), typica l of bridging carbonyls.