Hydration and sodium-ion binding of trifluoroacetate in aqueous solution

Identification of ion pairs in solution by IR spectroscopy: crucial contributions of gas phase data and simulations

“…29 On the theoretical side, ion pair type distributions have been calculated at 1 M using a force field specifically designed for electrolyte solutions. 30 On the experimental side, dielectric relaxation spectroscopy 31,32 as well as Fourier-Transformed Infrared (FTIR) and Raman experiments 5,6 have detected signals assigned to SIPs, while X-ray absorption spectroscopy experiments in microjets 33,34 claim to have detected CIPs in the same concentration range. In order to better understand these phenomena, we now endeavour to provide type-resolved vibrational spectra of ion pairs between a carboxylate anion and an alkali cation.…”

Vibrational spectroscopic studies and DFT calculations on NaCH3CO2(aq) and CH3COOH(aq)

“…[1][2][3] Detailed studies aimed at the hydration, dissociation and ion-pair formation of these species in solution were carried out by infrared [3][4][5] and dielectric relaxation spectroscopy (DRS). 6,7 DRS studies are useful in determining hydration numbers and association constants in electrolyte solutions forming ion pairs such as solvent shared-, solvent-solvent separated ion pairs and ion pairs without interposed water (contact ion pairs, CIPs). Such studies were carried out on aqueous solutions of sodium salts of acetate (CH 3 CO 2 − ‡) and formate (HCO 2 − ) as well as trifluoroacetate (CF 3 CO 2 − ) 6, 7 Hess and Vegt 1 studied the interaction of alkali metal cations with carboxylate ions in aqueous solution, in an effort to unravel cation specific binding with protein surface charges.…”

“…6,7 DRS studies are useful in determining hydration numbers and association constants in electrolyte solutions forming ion pairs such as solvent shared-, solvent-solvent separated ion pairs and ion pairs without interposed water (contact ion pairs, CIPs). Such studies were carried out on aqueous solutions of sodium salts of acetate (CH 3 CO 2 − ‡) and formate (HCO 2 − ) as well as trifluoroacetate (CF 3 CO 2 − ) 6, 7 Hess and Vegt 1 studied the interaction of alkali metal cations with carboxylate ions in aqueous solution, in an effort to unravel cation specific binding with protein surface charges. They concluded the existence of solvent separated ion pairs in aqueous solution between the monovalent cations and acetate according to the following order: K + < Na + < Li + .…”

HYDRATION OF CBr3COOH MOLECULES AND CBr3CO ANIONS IN AQUEOUS SOLUTIONS

“…Ɋɚɛɨɬɵ, ɩɨɫɜɹɳɟɧɧɵɟ ɝɢɞɪɚɬɚɰɢɢ ɤɚɪɛɨɧɨɜɵɯ ɤɢɫɥɨɬ ɜ ɠɢɞɤɨɣ ɮɚɡɟ, ɧɟɦɧɨɝɨɱɢɫɥɟɧɧɵ [7][8][9][10][11][12]. Ɇɟɬɨɞɨɦ ɞɢɷɥɟɤɬɪɢɱɟɫɤɨɣ ɪɟɥɚɤɫɚɰɢɢ ɩɨɤɚɡɚɧɨ, ɱɬɨ ɜ ɜɨɞɧɵɯ ɪɚɫɬɜɨɪɚɯ NaCHCO 2 , NaCH 3 CO 2 ɢ NaCF 3 CO 2 ɩɪɢ ɛɟɫɤɨɧɟɱɧɨɦ ɪɚɡɛɚɜɥɟɧɢɢ ɢɨɧɵ CHCO 2 , CH 3 CO 2 ɢ CF 3 CO 2 ɫɥɚɛɨ ɫɜɹɡɚɧɵ ɫ a20 ɦɨɥɟɤɭɥɚɦɢ ɜɨɞɵ [ 7,8 ].…”

“…Ɋɚɛɨɬɵ, ɩɨɫɜɹɳɟɧɧɵɟ ɝɢɞɪɚɬɚɰɢɢ ɤɚɪɛɨɧɨɜɵɯ ɤɢɫɥɨɬ ɜ ɠɢɞɤɨɣ ɮɚɡɟ, ɧɟɦɧɨɝɨɱɢɫɥɟɧɧɵ [7][8][9][10][11][12]. Ɇɟɬɨɞɨɦ ɞɢɷɥɟɤɬɪɢɱɟɫɤɨɣ ɪɟɥɚɤɫɚɰɢɢ ɩɨɤɚɡɚɧɨ, ɱɬɨ ɜ ɜɨɞɧɵɯ ɪɚɫɬɜɨɪɚɯ NaCHCO 2 , NaCH 3 CO 2 ɢ NaCF 3 CO 2 ɩɪɢ ɛɟɫɤɨɧɟɱɧɨɦ ɪɚɡɛɚɜɥɟɧɢɢ ɢɨɧɵ CHCO 2 , CH 3 CO 2 ɢ CF 3 CO 2 ɫɥɚɛɨ ɫɜɹɡɚɧɵ ɫ a20 ɦɨɥɟɤɭɥɚɦɢ ɜɨɞɵ [ 7,8 ]. Ⱥɧɢɨɧɵ ɭɤɫɭɫɧɨɣ ɢ ɬɪɢɮɬɨɪɭɤɫɭɫɧɨɣ ɤɢɫɥɨɬ ɜɨ ɜɫɟɦ ɜɨɡɦɨɠɧɨɦ ɞɢɚɩɚɡɨɧɟ ɤɨɧɰɟɧɬɪɚɰɢɣ ɩɪɨɱɧɨ ɝɢɞɪɚɬɢɪɨɜɚɧɵ 1-2 (ɩɪɟɢɦɭɳɟɫɬɜɟɧɧɨ ɞɜɭɦɹ) ɦɨɥɟɤɭɥɚɦɢ, ɚ ɩɪɢ ɩɪɟɞɟɥɶɧɨɦ ɧɚɫɵɳɟɧɢɢ ɪɚɫɬɜɨɪɚ ɫɥɚɛɨ ɜɡɚɢɦɨɞɟɣɫɬɜɭɸɬ ɫ 3-4 ɦɨɥɟɤɭɥɚɦɢ H 2 O. ɉɪɢ ɢɡɭɱɟɧɢɢ ɝɢɞɪɚɬɚɰɢɢ ɭɤɫɭɫɧɨɣ [ 9 ] ɢ ɬɪɢɛɪɨɦɭɤɫɭɫɧɨɣ [ 10 ] ɤɢɫɥɨɬ ɦɟɬɨɞɚɦɢ ɤɨɥɟɛɚɬɟɥɶɧɨɣ ɫɩɟɤɬɪɨɫɤɨɩɢɢ ɫɩɟɤɬɪɵ ɜɨɞɧɵɯ ɪɚɫɬɜɨɪɨɜ ɤɢɫɥɨɬɵ ɢ ɟɟ ɧɚɬɪɢɟɜɨɣ ɫɨɥɢ ɛɵɥɢ ɫɨɩɨɫɬɚɜɥɟɧɵ ɫ ɪɚɫɫɱɢɬɚɧɧɵɦɢ (B3LYP/6-311++G(3df,2pd)) ɜ ɩɪɢɛɥɢɠɟɧɢɢ ɩɨɥɹɪɢɡɭɟɦɨɣ ɩɨɥɨɫɬɢ (ɩɪɢɛɥɢɠɟɧɢɢ PCM (Polarizable Continuum Model)) ɫɩɟɤɬɪɚɦɢ ɦɨɥɟɤɭɥ CH 3 COOH, CBr 3 COOH ɢ ɚɧɢɨɧɨɜ CH 3 CO 2 , CBr 3 CO 2 .…”