Dynamic structures of aqueous oxalate and the effects of counterions seen by 2D IR.
Phys Chem Chem Phys
; 14(18): 6219-24, 2012 May 14.
Article
em En
| MEDLINE
| ID: mdl-22314844
ABSTRACT
Two dimensional vibrational echo spectra of oxalate in the carboxylate asymmetric stretch region in D(2)O 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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oxalatos
/
Água
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article