Partial molar heat capacities and volumes of transfer of nucleic acid bases, nucleosides and nucleotides from water to aqueous solutions of sodium and calcium chloride at 25�C

Abstract

Partial molar heat capacities\(\overline C _{p2}^o \) and volumes\(\overline V _2^o \) of some nucleic acid bases, nucleosides and nucleotides have been measured in 1m aqueous NaCl and CaCl2 solutions using Picker flow microcalorimeter and a vibrating tube digital densimeter. The partial molar heat capacities of transfer and volumes of transfer from water to the electrolyte solutions were calculated using earlier data for these compounds in water. The values of these transfer parameters are positive. The higher values for transfer to aqueous CaCl2 solutions reflect the stronger interactions of the constituents of the nucleic acids with Ca+2 ions than with the Na+ ions.