Synthesis and Characterization of Ru(III) Complexes Containing Quinazoline Derivatives and their Biological and Catalytic Activities

Abstract

Ruthenium trichloride trihydrate (RuCl3·3H2O) reacted with quinazoline derivative ligands (L) in 1:1 mole ratio in acetone to yield a series of brown/green/greenish black ruthenium(III) complexes of the type RuX3L·nH2O where X = Cl, n = 0, 1, 2 and 3 and L is 6-R-5,6-dihydrobenzoimidazo[1,2- c]quinazoline (R = ethyl: L1/n or i-propyl: L2, L3/n or i-butyl: L4, L5/phenyl: L6/furyl: L7/thiophenyl: L8/o or p-hydroxyphenyl: L9, L10/o or p-chlorophenyl: L11, L12/dimethylaminophenyl: L13). All the synthesized Ru(III) complexes were characterized by elemental analyses, conductivity measurements, infrared, electronic, ESR and mass spectral techniques, TGA, magnetic susceptibility and electrochemical studies. A square pyramidal geometry around the metal ion was proposed for all the complexes. The biological activities of the ligand and its ruthenium(III) complexes have been studied on microorganisms such as B. subtilis, E. coli and yeast by cup-plate method. The catalytic activity of the synthesized ruthenium(III) complexes towards oxidation of benzyl alcohol, cyclohexanol and hydroquinone was also carried out in acetonitrile with tert.-butyl hydroperoxide (t-BuOOH) as co-oxidant.