Reactivity of Silylated Dinuclear Iron−Platinum Acyl Complexes: Formation of μ-Vinylidene Complexes and Crystal Structures of the Acyl Complex [(OC)3{(MeO)3Si}Fe(μ-dppm)Pt{C(O)Me}(t-BuNC)] and the μ-Vinylidene Complex [(OC)3Fe{μ-CC(H)Ph}(μ-dppm)Pt(PPh3)]

Addition of RNC to the heterobimetallic acyl complex [(OC) 3 Fe{μ-Si(OMe) 2 (OMe)}(μ-dppm)Pt{C(O)Me}] ( 1a ), which displays a μ−η 2 -Si−O bridge, afforded the isonitrile adducts [(OC) 3 {(MeO) 3 Si}Fe(μ-dppm)Pt{C(O)Me}(C⋮NR)] ( 3a R = t -Bu, 3b R = 2,6-xylyl). Upon treatment of a CH 2 Cl 2 solution of 1a with MeO 2 CC⋮CCO 2 Me (DMAD), alkyne insertion into the Pt−C bond gave the alkenyl complex [(OC) 3 Fe{μ-Si(OMe) 2 (OMe)}(μ-dppm)Pt{(MeO 2 C)C C(CO 2 Me)C(O)Me}] 4 . The isonitrile adducts [(OC) 3 {(MeO) 3 Si}Fe(μ-dppm)Pt{(MeO 2 C)C C(O 2 Me)C(O)Me}(C⋮NR)] ( 5a R = t -Bu, 5b R = 2,6-xylyl)] were isolated after addition of RNC. A more complex reaction occurred when phenylacetylene or tert -butylacetylene were reacted with 1a . The iron-bound Si(OMe) 3 group and the organic ligand coordinated on platinum were eliminated, and the vinylidene-bridged complexes [(OC) 3 Fe{μ-C C(H)R}(μ-dppm)Pt(CO)] ( 6a R = Ph, 6b R = t -Bu, 6c R = n -Bu) were obtained. The loosely Pt-bound CO ligand of 6a − c was readily displaced by PPh 3, P(OMe) 3, or 2,6-xylyl isonitrile yielding the substitution products [(OC) 3 Fe{μ-C C(H)R}(μ-dppm)Pt(L)] ( 7a R = Ph, L = PPh 3; 7b R = t -Bu, L = PPh 3; 7c R = t -Bu, L = P(OMe) 3; 7d R = t -Bu, L = 2,6-xylylNC). The heterobimetallic phenyl complex [(OC) 3 Fe{μ-Si(OMe) 2 (OMe)}(μ-dppm)Pt(Ph)] ( 8 ) was obtained by reaction of K[Fe{Si(OMe) 3 }(CO) 3 (η 1 -dppm)] with a cold THF solution of [PtCl(Ph)(1,5-COD)]. The μ−η 2 -Si−O bridge is readily opened under a CO atmosphere to give the CO adduct [(OC) 3 Fe{Si(OMe) 3 }(μ-dppm)Pt(CO)(Ph)] ( 9 ), which unexpectedly does not insert CO into the Pt−phenyl bond. This complex reversibly loses the CO ligand under reduced pressure to regenerate 8 . All complexes have been studied by multinuclear NMR spectroscopy. The solid state structures of complexes 3a and 7a have been determined by single-crystal X-ray diffraction.