文摘
The density of glycine, mallcaps">l-alanine, and mallcaps">l-serine in formamide鈥搘ater mixtures was measured at 298.15 K and used to calculate the apparent molar volume V and limiting partial molar volume V掳 of the amino acids. Transfer partial molar volume 螖trV掳 from water to formamide鈥搘ater mixtures and the volumetric interaction coefficients were also obtained to interpret the solute鈥搒olvent interaction. Values of 螖trV掳 of the three amino acids were all positive and increased with increasing formamide concentration in the mixtures, in the order of mallcaps">l-alanine < glycine < mallcaps">l-serine, which was consistent with the cosphere overlap model. The interaction of formamide molecules decreased its structural-breaking effect and consequent interaction with amino acids, leading to negative triplet interaction coefficients.