A new route for the synthesis of bis(pyridine dicarboxylato)bis(triphenylphosphine) complexes of ruthenium(II) and X-ray structural characterisation of the biologically active trans-[Ru(PPh3)2(L1H)2] (L1H2 = pyridine 2,3-dicarboxylic acid)

Ruthenium(II) complexes of the general formula Ru(LH)(2)(PPh3)(2), (LH2 = pyridine 2,3-, 2,4-: 2,5- and 2,6-dicarboxylic acid) are synthesised by a new method. All the pyridine dicarboxylic acids are found to behave as bidentate, monobasic chelating donors, with one carboxyl group remaining idle. The electrochemical behaviour of the compounds is explored with the help of cyclic voltammetry. The antibacterial activities of these compounds were examined against Escherichia coli in nutrient broth in order to check their potential for antitumour activity. Single-crystal X-ray analysis of the complex involving pyridine 2,3-dicarboxylic acid ((LH2)-H-1) revealed that the coordination environment consists of a centrosymmetric, axially elongated N2P2O2 octahedron with a pair of coordinated (LH)-H-1 ligands occupying the equatorial plane. (C) 2001 Elsevier Science Ltd. All rights reserved.