Density, Viscosity and Ultrasonic Speed Based Acoustical Studies of Structural Properties of 1,1’-Bis(4-Amino Phenyl) Cyclohexane Symmetric Double Schiff Bases in THF Solutions at 303.15, 308.15 and 313.15K

The density ( rho ), viscosity ( eta ) and ultrasonic speed (U) (2MHz) of THF solutions of symmetric double Schiff bases (SDSB-1,SDSB-2 and SDSB-3) were determined at 303.15, 308.15 and 313.15 K. Various acoustical parameters such as specific acoustical impedance (Z), isentropic compressibility ( Kappa sub( s)), Rao's molar sound function (R sub( m)), Van der Waals constant (b), internal pressure ( pi ), free volume (V sub( f)), intermolecular free path length (L sub( f)), viscous relaxation time ( tau ) and classical absorption coefficient ( alpha /f super( 2)) sub( Cl)), were determined using rho , eta and U data. The results are interpreted in terms of molecular interactions occurring in the solutions at different temperatures and concentrations. Linear increase of rho , eta U, Z, R sub( m), b, ( alpha /f super( 2)) sub( Cl) and tau with increasing C, linear decrease of K sub( S), L sub( f) and pi with increasing T, V sub( f) increased linearly with C and T except SDSB-3 supported existence of strong molecular interactions in the solutions and confirming solvophilic nature of the Schiff bases. The structure, nature and size of the solutes and solvent, concentration and temperature affected molecular interactions.