REFRACTIVE INDEX FOR ALANINE, GLUTAMIC ACID AND HISTIDINE IN AQUEOUS NaCl SOLUTIONS AT DIFFERENT TEMPERATURES

Experimental refractive index data for L-alanine, L-histidine and L-glutamic acid in aqueous NaCl solutions at different temperatures (293.15, 298.15, 303.15, 313.15 and 323.15 K) and ambient pressure are reported. The obtained data were used to calculate molar refraction and overall polarizability of the solutions. Moreover, the Lorentz-Lorenz empirical equation was employed to correlate density previous data with refractive index for binary and ternary systems containing the investigated amino acids, water and NaCl. Results are interpreted in terms of interactions in these mixtures. Additionally, a computational investigation of dipole moment and molecular polarizability by density functional theory (DFT) at wB97XD/6-31 G+(d,p) level is presented.