Density, Sound Speed, and Viscosity of Dihydropyridine Derivatives in Dimethyl Sulfoxide at Different Temperatures

Some novel dihydropyridine derivatives, viz., 4-(4-hydroxy-3-methoxyphenyl)-6-(2-hydroxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile, 4-(4-hydroxy-3-methoxypheny)-6-(4-hydroxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile, 6-(4-chlorophenyl)-4-(4-hydroxy-3methoxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitile, and 4-(4-hydroxy-3-methoxyphenyl)-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile have been synthesized, and characterization of these synthesized compounds has been done by IR, H-1 NMR, C-13 NMR, and mass analyses. The densities (rho), viscosities (eta), and ultrasonic velocities (U) of these dihydropyridine derivatives have been measured in dimethyl sulfoxide at different temperatures over a wide range of molalities. From these experimental data for rho, eta, and U, various acoustical parameters and some apparent molar parameters have been calculated. The obtained results are interpreted in terms of solute-solvent and solute-solute interactions, giving an idea of the structure-making or structure-breaking abilities of the studied compounds in dimethyl sulfoxide solution.