Growth of the metal framework in linear ruthenium and osmium carbonyls

Computational DFT Study of Ruthenium Tetracarbonyl Polymer

Ruthenium tetracarbonyl polymer, [Ru(CO)4]n, a chainlike compound formed by metal-metal interactions, was studied computationally. We first performed tests with selected pure and hybrid GGA density functionals and ab initio methods at HF and MP2 levels of theory to find the most suitable method. Calculated geometries and molecular orbitals were compared to see effectiveness and possible differences of the methods. Hybrid functionals, especially PBE1PBE and MPW1K, were found to produce accurate geometrical parameters compared to the experimental structure, with reasonable computational cost. Bonding in [Ru(CO)4]n chains was studied by calculation of Mayer bond order and theoretical structure factors followed by multipole refinement to get bond critical points according to the quantum theory of atoms in molecules. Ruthenium-ruthenium bonding comparable to that in a Ru3(CO)12 cluster was found with both methods.

The subtle effects of iron-containing metal surfaces on the reductive carbonylation of RuCl3

The use of iron-containing metal surfaces, Fe, Fe-Cr-alloy and stainless steel, for the synthesis of mixed metal Ru-Fe compounds has been studied. The studied process was reductive carbonylation of RuCl3 in the presence of a metal surface. Reactions were carried out in ethanol solutions under 10-50 bar carbon monoxide pressure at 125 degrees C using an autoclave. During the reaction the metal surface was oxidized, releasing iron into the solution and acting as a sacrificial source of iron. Under these conditions the corrosion of the metal surface was facile and produced a series of iron-containing species. In addition to the formation of most obvious iron(II) products, such as [Fe(H2O)6]2+ or [FeCl2(H2O)4] the use of the metal surface also provided a route to novel labile trinuclear [Ru2Cl2(mu-Cl)4(CO)6FeL2] (L = H2O, EtOH) complexes. The stability and reactivity of the [Ru2Cl2(mu-Cl)4(CO)6FeL2] complexes were further studied using computational DFT methods. Based on the computational results a reaction route has been suggested for the formation and decomposition of [Ru2Cl2(mu-Cl)4(CO)6FeL2].