η1‐Coordination of Phosphinine C5H5P and Arsenine C5H5As to Ruthenium(II) and Osmium(II)

Abstract

AbstractReductive complexation of RuCl3 and OsCl3 in the presence of phosphinine C5H5P and arsenine C5H5As yields the species trans‐Cl2(η1‐C5H5E)4MII (M = Ru, E = P, As; M = Os, E = P). trans‐Cl2(η1‐C5H5As)4Ru constitutes the first arsenine complex of a late transition metal. Further reduction and isolation of the binary complexes (C5H5E)nM0 (n = 2, 4, 5) failed, presumably because of metal–ligand bond cleavage. According to X‐ray diffraction analysis, trans‐Cl2(η1‐C5H5P)4Ru (3) features two pairs of coplanar trans‐phosphinine ligands, which adopt eclipsed and staggered orientations, respectively, with regard to the Cl–Ru–Cl backbone. DFT calculations indicate a flat curvature of the potential governing conformational change and predict a structure for 3 that differs from that observed in the crystal. This illustrates the need to include intermolecular Ru–Cl···H hydrogen bonding as a structural director. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)