SYNTHESIS AND CHARACTERIZATION OF THE FIRST SERIES OF ISOLABLE (NITRO)RUTHENIUM(III) COMPLEXES - A DECOMPOSITION MECHANISM OF THE (NITRO)RUTHENIUM(III) MOIETY

The first series of isolable (nitro) ruthenium(III) complexes were pre pared by the chemical oxidation of trans-[Ru(NO2)(PR(3))(2)(trpy)](+) (R=methyl (Me), ethyl (Et), and n-propyl (n-Pr)) and trans-[Ru(NO2)(PM e(3))(PR(3))(trpy)](+) (R = Et and n-Pr). These complexes were charact erized by elemental analysis, cyclic voltammetry, UV-Vis spectroscopy and magnetic susceptibility. A study of the decomposition reactions of these complexes in acetonitrile at 25 degrees C was undertaken, where the products were identified by UV-Vis spectroscopy and cyclic voltam metry. The product distribution changed from a 1:1:1 ratio of (PR(3))( 2)(trpy)](2+):[Ru(NO2)(PR(3))(2)(trpy)](+) to a 1:1 ratio of )(PR(3))( 2)(trpy)](3+):[Ru(NO3(PR(3))(2)(trpy)](+) depending on the R group of the PR, ligands. The electrochemical data, combined with an (NO2)-N-15 IR spectroscopic labeling study on the most and least stable complexe s in the series, suggests the decomposition mechanism involves nitro-n itrito linkage isomerization, followed by the formation of a transitor y dimeric species that breaks apart into the final products.