Ruthenium complexes of the scorpionate ligand bis(3,5-dimethylpyrazol-1-yl) -dithioacetate and the effect of nitric oxide coordination

Article abstract of DOI:10.1002/ejic.200401062

Six new ruthenium(II) complexes with the scorpionate ligand bis(3,5-dimethylpyrazol-1-yl)dithio-κ³N,N,S-acetate (bdmpzdta) were obtained by treatment of the ligand with RuCl₃ or [RuCl ₃(NO)] in 1:1 or 2:1 molar ratios in the presence or absence of ethylenediamine. In all six complexes the pyrazolic rings lie in the equatorial plane. The mononitrosyl complexes present a sharp ν(NO) band in the range 1864-1859 cm^-1 for samples prepared either as KBr tablets or dichloromethane solutions. In the case of [Ru(NO)-(bdmpzdta)₂]Cl (7), the dithiocarboxylate group of one of the ligands is not coordinated (κ²N,N). In the other five complexes, however, bdmpzdta behaves as a κ³N,N,S scorpionate ligand. When the complexes obtained from RuCl₃ were dissolved in dichloromethane and NO was bubbled through the solution, a high degree of coordination of NO⁺ was observed, according to IR, UV and voltammetric studies. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.