Cation-Specific Interactions with Carboxylate in Amino Acid and Acetate Aqueous Solutions: X-ray Absorption and ab initio Calculations

Citations Over TimeTop 10% of 2008 papers

Abstract

Relative interaction strengths between cations (X = Li (+), Na (+), K (+), NH 4 (+)) and anionic carboxylate groups of acetate and glycine in aqueous solution are determined. These model systems mimic ion pairing of biologically relevant cations with negatively charged groups at protein surfaces. With oxygen 1s X-ray absorption spectroscopy, we can distinguish between spectral contributions from H 2O and carboxylate, which allows us to probe the electronic structure changes of the atomic site of the carboxylate group being closest to the countercation. From the intensity variations of the COO (-) aq O 1s X-ray absorption peak, which quantitatively correlate with the change in the local partial density of states from the carboxylic site, interactions are found to decrease in the sequence Na (+) > Li (+) > K (+) > NH 4 (+). This ordering, as well as the observed bidental nature of the -COO (-) aq and X (+) aq interaction, is supported by combined ab initio and molecular dynamics calculations.

Related Papers

• → Thermoelectric properties of p-type LiZnSb: Assessment of ab initio calculations(2009)75 cited
• → Electronic absorption spectroscopy and time-dependent density functional theory calculations on the nickel(II) complex of 1,4-bis(pyrrol-2-ylmethyleneamino)butane(2008)33 cited
• → Investigation on molecular structure of molten Li2BeF4 (FLiBe) salt by infrared absorption spectra and density functional theory (DFT)(2017)23 cited
• → Reply Ab initio vibrational raman spectra of small ring molecules: Examples that warrant reevaluation of a scaling theme(1989)7 cited
• Ab Initio Studies of Chlorine Oxide and Nitrogen Oxide Species of Interest in Stratospheric Chemistry(1995)