Ruthenium complexes containing pyridine-2,6-dicarboxylato ligands

Treatment of RuCl3 center dot 3H(2)O, [Et4N][RuCl4(CH3CN)(2)] or [Ru(DMSO)(4)Cl-2] with the ligand pyridine-2,6-dicarboxylic acid (dipicH(2)) in the presence of Et3N afforded the mononuclear complex [Et3NH](2) [Ru(kappa(3)-dipic)Cl-3] (1), [Et4N][Ru(kappa(3)-dipic)(MeCN)Cl-2] (2) or [Et3NH][Ru(kappa(3)-dipic)-(DMSO)(2)Cl] (4), respectively, with a kappa(3)-dipic coordination mode. Reaction of [Ru(CO)(2)Cl-2](x) or [Ru(NO)(PPh3)(2)Cl-3] with dipicH(2) in the presence of Et3N gave the mononuclear complex [Et3NH](2)[Ru(kappa(2)-dipic)(CO)(2)Cl-2] (3) or [Et3NH][Ru(kappa(2)-dipic)(NO)(PPh3)Cl-2] (5), respectively, with a kappa(2)-dipic coordination mode. Reaction of [Et4N][RuCl4(CH3CN)(2)] with dipicH(2) in the presence of AgNO3 in EtOH/MeCN resulted in a dianionic Ru(III) complex, [Et4N](3)[Ru(kappa(3)-dipic)(2)][Ru(kappa(3)-dipic)(kappa(2)-dipic)Cl] (6), with the mixed kappa(3)-dipic and kappa(2)-dipic coordination modes. Interaction of RuCl3 center dot 3H(2)O with dipicH(2) and Et3N gave the dinuclear Ru(III) complex [Et3NH](2)[Ru(kappa(3)-dipic)(mu(2)-kappa(1), kappa(2)-dipic)](2) (7) with a bridging mu-kappa(1), kappa(2)-dipic coordination mode. All complexes have been spectroscopically characterized along with the electrochemical analyses. The structures of 1, 2, 3 center dot H2O, 4, 5 center dot 1/2Et(2)O, 6 center dot CH2Cl2 center dot C6H14, 7 center dot CH2Cl2 have been also determined by single-crystal X-ray diffraction. (C) 2015 Elsevier B.V. All rights reserved.