Ruthenium- and osmium-promoted oxidation of aromatic amines. Some observations in the area of metal-diimines

摘要

Three reactions of aniline with Ru(acac)3, RuCl3.3H2O and (NH4)2[OsBr6] are reported. The isolated complexes are Ru(acac)2L, RuCl2(aniline)2L and OsBr2L2 (L= N-phenyl-l,2-phenylene diimine) respectively. In all the cases oxidation of aniline has occurred to result in diimine chelates. The products of the above reactions have been fully characterized and their X-ray structures are reported. The bond length trends within the chelate as well as the aromatic rings are consistent with the diimine character of the coordinated ligand. A qualitative pathway for the formation of L is suggested. A correlation between the metal oxidation levels in the starting compounds and the products with the number of ligand formation is noted.