Ru(III) complexes containing 3,5-pyrazole dicarboxylic acid and triphenylphosphine/triphenylarsine: Synthesis, characterization and catalytic activity

New hexa-coordinated Ru(III) complexes of the type [Ru(H2Pzdc)(EPh3)3X2] have been synthesized by reacting 3,5-pyrazole dicarboxylic acid (H3Pzdc) with the appropriate starting complexes [RuX3(EPh3)3] (where X = Cl or Br; E = P or As). The ligand behaves as a bidentate monobasic chelate. All the complexes have been characterized by analytical and spectroscopic (IR, electronic and EPR) data. Single-crystal X-ray analysis of the complex [Ru(H2Pzdc)(PPh3)2Cl2]·C6H6·C2H5OH revealed that the coordination environment around the ruthenium center consists of an NOP2Cl2 octahedron. The planar ligand occupies the equatorial position along with two chlorine atoms, while the triphenylphosphine groups occupy the axial positions. The electrochemical behavior of the new complexes was studied using cyclic voltammetry. The new mononuclear ruthenium complexes are capable of acting as catalysts for the oxidation of alcohols.

Hexa-coordinated Ru(III) complexes of the type [Ru(H2Pzdc)(EPh3)2X2] have been synthesized by reacting 3,5-pyrazole dicarboxylic acid with the appropriate starting complexes [RuX3(EPh3)3] (X = Cl or Br; E = P or As). All complexes have been characterized by analytical and spectroscopic data. Crystal structure of the complex [Ru(H2Pzdc)(PPh3)2Cl2]·C6H6·C2H5OH revealed that the coordination environment around ruthenium metal consists of an NOP2Cl2 octahedron.Figure optionsDownload as PowerPoint slideResearch highlights
► The ligand behaves as a bidentate monobasic chelate.
► The coordination around Ru metal consists of an NOP2Cl2 octahedron.
► The Ru(III) complexes are capable of acting as catalysts for oxidation of alcohols.