SYNTHESIS AND REACTIVITY OF SILYLATED DINUCLEAR IRON-PLATINUM COMPLEXES CONTAINING A PT-C BOND, CRYSTAL-STRUCTURES OF [(OC)(3)FE(MU-SI(OME)(2)(OME))(MU-DPPM)PT(NBN)] (DPPM=PH(2)PCH(2)PPH(2), NBN=NORBORNYL, C7H11), [(OC)(3)((MEO)(3)SI)FE(MU-DPPM)PT(ETA(3)-C8H13)] AND )FE(MU-PPH(2))PT(ETA(4)-PPH(2))PT(ETA(4)-1,5-COD)]

Silylated bimetallic Fe-Pt-complexes have been prepared by reaction be tween the iron metallate trans-[Fe{Si(OMe)(3)}(CO)(3)(dppm-P)](-) (dpp m = Ph(2)PCH(2)PPh(2)) and [PtCl(Me)(1,5-cod)] or by oxidative-additio n/insertion of the Fe-H bond of the corresponding iron hydride with Pt (O) complexes. We report the crystal structure of three such complexes , [(OC)(3)[(MeO)(3)Si]Fe(mu-dppm)Pt(eta(1)-nbn)], 2c (nbn = norbornyl, C7H11), [(OC)(3){(MeO)(3)si}Fe(mu-dppm)Pt(eta(3)-C8H13)], 8, and [(OC )(3){(MeO)(3)Si}Fe(mu-PPh(2))Pt(1,5-cod)] (cod = cyclo-octadiene), 10a . These general methods provide access to complexes containing the ver satile heterobimetallic moiety [(OC)(3){(MeO)(3)Si}Fe(mu-L)Pt] (L = PP h(2), dppm) which can interact via the platinum atom with an organic l igand in three different ways. In the p-dppm derivatives the organic f ragment may be attached to the platinum centre in an eta(3)-manner, as in the pi-allylic-type cyclo-octenyl complex 8 or via a single sigma- bond, as in the methyl, ethyl and norbornyl derivatives 2a-c. In the l atter complexes, the platinum centre achieves its 16-e configuration v ia a two-electron donor SiO-->Pt-interaction involving the adjacent tr ialkoxysilyl ligand. In the mu-PPh(2) derivative 10a the olefinic doub le bonds of the 1,5-cod ligand coordinate to platinum in an eta(2)-man ner. The reactivity of these three different but related types of comp ounds towards CO is extremely different, leading to GO-insertion into the Pt-C bond or to CO/silyl mutual exchange by ligand migration from one metal centre to the other. A square-planar platinum complex contai ning mutually cis CO and CHI ligands has been isolated which is an int ermediate in the migratory insertion leading to acyl formation. The X- ray structures of 2c, 8 and 10a have been determined. Crystal data of 2c: monoclinic, space group P2(1)/n, a = 11.800(3), b = 20.245(6), c = 16.327(4) Angstrom, beta = 105.43(2)degrees, V = 3759.7 Angstrom(3), Z = 4, R(F) = 0.040, R(w)(F) = 0.062. Crystal data of 8: triclinic, sp ace group P1, a = 11.217(3), b = 12.661(3), c= 16.146(4) Angstrom, alp ha = 83.73(2), beta = 89.81(2), gamma = 64.64(2), V = 2057.3 A(3), Z = 2, R(F) = 0.044, R(w)(F) = 0.066. Crystal data of 10a: monoclinic, sp ace group P2(1)/c, a = 9.204(1), b = 15.689(1), c = 19.600(1) Angstrom , beta = 93.46(2), V = 2825.1 Angstrom(3), Z = 4, R(F) = 0.028, R(w)(F ) = 0.037.