Base hydrolysis of [Cr(ox) 2 (pda)] 3-(where pda is N,O-bonded 2,4-and 2,5-pyridinedicarboxylic acid dianion) causes successive ligand dissociation and leads to formation of a mixture of oligomeric chromium(III) species, known as chromates(III). The main reaction path proceeds through [Cr(ox)(pda)(OH) 2 ] 3-and [Cr(pda)(OH) 4 ] 3-complexes. The kinetics of the first oxalate dissociation was studied spectrophotometrically, within the lower energy d-d band region, at 0.4-1.0 M NaOH. The character of spectroscopic changes was consistent with a consecutive reaction model, where the chelate-ring opening and the one-end bonded oxalato liberation are the first and the second reaction stages. The pseudo-first order rate constants (k obs0 and k obs1 ) were calculated using SPECFIT software for an A ? B ? C reaction pattern. Additionally, kinetics of base hydrolysis of [Cr(ox) 3 ] 3-were studied. The calculated rate constants were independent of [OH 2 ]. Kinetic parameters for the chelate-ring opening and the first oxalate dissociation were determined. Effect of the [Cr(ox) 2 (pda)] 3-and [Cr(2,4-pda) 3 ] 3-complexes on 3T3 fibroblasts proliferation was studied. The results manifested low cytotoxicity of these complexes, which makes them promising candidates for dietary supplements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.