Titanium(iv) tartrate complexes in aqueous solutions

Complexation reactions in the system titanyl sulfate—(+)-tartaric acid were studied by potentiometric titration and mathematical modeling of equilibria over wide concentration ranges of the Ti IV ion and the ligand at pH 1.5—10.5. Complex species present in this system were identified for the first time, their constants of formation were calculated, and the nature of species at different pH values was determined. The model proposed provides a satisfactory description of the titanium( iv ) complexes in tartrate solutions over the whole concentration and pH ranges studied. The study revealed the formation of diand tetranuclear complexes, apart from mononuclear ones. It was found that Ti IV tartrates are more stable than Ti IV citrates of the same stoichiometry. The exception is [Ti(H 3 L) 2 ] 2+ , which is probably due to the participation of all OH groups of tartaric acid in complexation.