Abstract
The new mixed metal carbide containing cluster compounds PtFe4(CO)12(COD)(μ5-C) 1 and PtFe4(CO)12(PMe2Ph)2(μ5-C), 2 were obtained by metal–metal exchange reactions between [Et4N]2[Fe5(C)(CO)14] with Pt(COD)Cl2 in the presence of TIPF6 and Pt(PMe2Ph)2Cl2, respectively. Compound 1 was also obtained by the reaction of Fe5(CO)15(μ5-C) with Pt(COD)2 in the presence of UV irradiation but in a lower yield. Both compounds were characterized by a combination of IR, 1H NMR and single crystal x-ray diffraction analyses. Both complexes consists of a square pyramidal cluster of five metal atoms with an “interstitial” carbido ligand in the center of the square base. The phosphine ligands in 2 undergo a dynamical intramolecular interchange at a rate that is fast on the 1H NMR time scale at 45°C, ΔG† (at 318 K)=15.1 kcal/mol.
