Dynamic structures of aqueous oxalate and the effects of counterions seen by 2D IR
Two dimensional vibrational echo spectra of oxalate in the carboxylate asymmetric stretch region in D 2O show two transitions having anomalously slow spectral diffusion and a third transition having relaxation properties typical of the free carboxylate ion. Quantitative analysis of the frequency shifts of the carboxylate asymmetric stretch modes caused by a singly charged cation in the oxalate hydration shell supports that ion pairs can be responsible for these new transitions. Experimental evidence and DFT calculations are consistent with oxalate forming a mixture of "side-on" and "end on" contact ion pairs wherein the carboxylate groups are protected from mobile heavy water molecules. © the Owner Societies 2012.
Publication Source (Journal or Book title)
Physical Chemistry Chemical Physics
Kuroda, D., & Hochstrasser, R. (2012). Dynamic structures of aqueous oxalate and the effects of counterions seen by 2D IR. Physical Chemistry Chemical Physics, 14 (18), 6219-6224. https://doi.org/10.1039/c2cp23892f