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Zwitterionic nickel(II) compounds with a borate-containing anionic bidentate phosphine ligand (PBP − ) have been synthesized and some of them crystallographically characterized. The methyl complex, (PBP − )Ni + CH 3 (NCCH 3 ), reacts with H 2 to form an 12-membered macrocycle containing three Ni nuclei and reacts with carbon monoxide (CO) to afford the acetyl complex (PBP − )Ni + COCH 3 (CO). The square planar acetyl complex is stable in solution under 1 atm of CO but undergoes irreversible decomposition under high CO pressure at room temperature. X-Ray crystallographic characterization of a decomposition product revealed fragmentation of the anionic borate under high pressure. (PBP − )Ni + COCH 3 (CO) is an active catalyst for ethylene-CO copolymerization, but its productivity is low likely due to its instability under high CO pressure. [ABSTRACT FROM AUTHOR]

Abstract: A bidentate phosphine ligand with two amide arms, designed to form hydrogen bonds with electron-donating moieties, was synthesized and isolated in high diastereomeric excess (95% de). The hydrogen-bonding abilities of the ligand and its diastereomer were demonstrated with two rhodium complexes containing these ligands. The structures of the rhodium compounds are reminiscent of the well-studied picket-fence porphyrin systems. [Copyright &y& Elsevier]

Cobalt complexes of N-confused porphyrins and benziphthalocyanine, which both feature organometallic bonds at the macrocycle cores, catalyze the cyclopropanation of styrene with a higher trans-selectivity than the corresponding porphyrin and phthalocyanine complexes. [ABSTRACT FROM AUTHOR]

Abstract: The new pyridine-2-carboxaldehyde adduct, Re(CO)3(NC6H5C(O)H)Cl 1, and previously reported complex Re(CO)3(NC6H5C(O)H)Br 2 react with aniline derivatives sulfanilamide or 4-aminofluorescein in methanol giving Schiff base conjugates Re(CO)3(pyca-R)X (pyca = pyridinecarbaldehyde imine, X = Cl, Br), 3–6. Pre-isolation of compounds 1 and 2 provides a convenient method for preparing conjugate complexes in addition to the known methods of ligand synthesis and one-pot reactions. All new compounds were completely characterized, and compound 1 and the sulfanilamide derivatives 3 and 4 were structurally elucidated by X-ray crystallography. [Copyright &y& Elsevier]

The reaction of [Re(CO)3(H2O)3]Br or [Re(CO)5Cl] with two peptides, glycylglycine, or glycylalanine were investigated. Each reaction produced a unique, well-defined product. Structural elucidation showed the formation of chiral compounds with the formula [Re(CO)3(Gly-Xxx-O)]2, Xxx = Gly ( 1), Ala ( 2). Each dimer displays C2 symmetry and a nearly rectangular shape. The ligands are bound through the amine and amide carbonyl at a rhenium center and through the pendant carboxylate to the adjacent rhenium center. Both products are fully characterized by X-ray structure elucidation. [ABSTRACT FROM AUTHOR]

Abstract: Complexes of the type [Ru(bpy)2(OSOBnR)](PF6) where bpy is 2,2′-bipyridine and OSOBnR is a 4-substituted benzylsulfinylbenzoate with R=NO2, F, Cl, H, CH3, CF3 and OCH3, have been prepared and investigated by 1H NMR spectroscopy, cyclic voltammetry and UV–vis spectroscopy. Despite the distance of the R group from ruthenium, the Ru3+/2+ reduction potential and charge transfer absorption maximum vary predictably with the electron withdrawing nature of the group. [ABSTRACT FROM AUTHOR]