Interaction of [Ru(η6-p-cym)(H2O)3]2+ with citrate and tricarballate ions in aqueous solution; X-ray crystal structure of novel half-sandwich Ru(II)-citrato complexes

► Solution characterization of the [Ru(η6-p-cym)(H2O)3]2+ binding strength of citrate ion and its model, tricarballate ion with the aid of combined pH-potentiometric, 1H NMR and ESI-TOF-MS methods. ► Demonstration of the crucial role of the alcoholic/alcoholate function of the citrate in metal ion binding compared to a model tricarboxylic acid, tricarballylic acid. ► X-ray characterization of Ru(η6-p-cym)(citrH)]·H2O·CH3OH and 2[Ru(η6-p-cym)(citrH)]·3H2O both with [COO−, COO−, OH] binding mode.