The interaction between titanium(IV) and the croconate ion in aqueous solution studied by resonance Raman spectroscopy

In this work, a resonance Raman investigation was undertaken in order to elucidate the interaction between Ti(IV) and the croconate ion in aqueous solution. The intense orange-red color characteristic of the complex was assigned to a charge transfer transition around 400 nm. The Raman excitation profiles of the complex show an intensification pattern for the totally symmetric modes that is unusual for free oxocarbons. The modes involving the carbonyl groups are the most affected by coordination, exhibiting substantial shifts and splittings, which indicate that the interaction is quite strong, probably involving the oxocarbon carbonylic moities.