Density measurements on solutions of 2,4-dimethy1-6,8-diethy1-2,4,6,8-tatraazabicyclo[3.3.0]octane-3,7-dione or Mebicaret in normal (H2O) and heavy (D2O) water were carried out with a precision of 0.012 kg.m(-3) using the Anton Paar DMA 5000 M vibrating tube densimeter. All experiments were performed within the temperature range between 278.15 K and 318.15 K (with a step of 10 K) at the pressure to be ca. 99.6 kPa. The solution aquamolality was ranged from 0.02 to 02 mol.(55.51 mol of solvent)(-1) for each of H/D isotopically distinguishable systems compared. The standard (partial at infinite dilution) molar volumes (V-2(o)) and expansibilities (E-p,2(o)) of the solute as well as volume-kelated second virial coefficients (v(22)) were derived from the data on a solution density. The behavior of solvent isotope effects (lEs) on the considered quantities was described given the structure and interaction-related peculiarities of the Mebicaret molecule as well as H2O and D2O media. The volume-related interaction characteristics for the solute of interest were discussed using the results of our previous densimetric and calorimetric studies with the participation of similar N-tetraalkylated glycoluril-derivatives.
