Sung Hwan. Han

Halide promotion of the formation and carbonylation of μ3-imido ligands. Relevance to the halide promotion of nitroaromatic carbonylation catalysis

Abstract The individual reaction steps that are believed to occur during the catalytic carbonylation of nitroaromatics to form isocyanates, carbamates, amines, and ureas are reviewed with focus on stoichiometric organometallic reactions that model the proposed reaction steps. Especially emphasized are recent studies that show how halides dramatically promote both the formation and carbonylation of imido ligands. These results provide insight into the role that halides play in the known halide promoted Ru 3 (CO) 12 catalytic system for the formation of methyl N -phenylcarbamate from nitrobenzene, CO, and methanol [S. Cenini et al., J. Chem. Soc., Chem. Commun. 1984, 1286].

An examination of bent semi-bridging metal carbonyl bonding II. Polymorphism and multiple independent molecules in [H2Ru4(CO)13]☆

A triclinic polymorph of [H2Ru4(CO)13] has been crystallographically characterized: P1, a 9.062(2), b 9.155(2), c 26.649(6) A, α 81.80(2), β 88.03(2), γ 67.76(2)°, V 2024.9(8) A3, Z = 4, RF 2.31%. Both this polymorph and a previously studied monoclinic polymorph [D.B.W. Yawney and R.J. Doedens, Inorg. Chem., 11 (1972) 838] crystallize with two independent molecules in the asymmetric units. A wide range of bond parameters are found for the two bent semi-bridging μ-CO ligands in each of the four chemically identical molecules in the two polymorphs. However, despite the wide range of values, which are attributed to crystal packing forces, each μ-CO group conforms exactly to the linear Crabtree-Lavin relationship [R.H. Crabtree and M. Lavin, Inorg. Chem., 25 (1986) 805].