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)((LH)-H-1)(2)] ((LH2)-H-1 = pyridine 2,3-dicarboxylic acid)

Ruthenium(II) complexes of the general formula Ru(LH)(2)(PPh3)(2), (LH2 = p yridine 2,3-, 2,4-: 2,5- and 2,6-dicarboxylic acid) are synthesised by a ne w method. All the pyridine dicarboxylic acids are found to behave as bident ate, monobasic chelating donors, with one carboxyl group remaining idle. Th e electrochemical behaviour of the compounds is explored with the help of c yclic voltammetry. The antibacterial activities of these compounds were exa mined against Escherichia coli in nutrient broth in order to check their po tential for antitumour activity. Single-crystal X-ray analysis of the compl ex involving pyridine 2,3-dicarboxylic acid ((LH2)-H-1) revealed that the c oordination environment consists of a centrosymmetric, axially elongated N2 P2O2 octahedron with a pair of coordinated (LH)-H-1 ligands occupying the e quatorial plane. (C) 2001 Elsevier Science Ltd. All rights reserved.