Ruthenium(III) chalconate complexes containing PPh₃/AsPh₃ and their use as catalysts

Abstract

Ruthenium(III) complexes of the type [RuX(EPh₃)(L)₂] (X = Cl or Br; E = P or As; L = 2-hydroxychalcone) have been prepared by reacting [RuX₃(EPh₃)₃] with 2-hydroxychalcones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (infrared, electronic, electron paramagnetic resonance, and mass) methods. Redox potential studies of the complexes have been carried out to elucidate the electronic structure, geometry, and electrochemical features. On the basis of data obtained, an octahedral structure has been assigned for all the complexes. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide as co-oxidant and they were also found to be efficient catalyst for the transfer hydrogenation of ketones.

Keywords:

• Ruthenium(III) complexes
• Spectroscopic characterization
• Cyclic voltammetry
• Catalytic activity

Acknowledgments

The authors express their sincere thanks to Council of Scientific and Industrial Research (CSIR), New Delhi [Grant No. 01(2065)/06/EMR-II] for financial support. M. Muthukumar thanks CSIR for the award of Senior Research Fellowship.