Acoustical study of substituted azoles in N, N -dimethylformamide at different temperatures

Abstract

Ultrasonic velocity and density measurements of 2-(5-amino-[1,3,4]thiadiazol-2-yl)-phenol) (L₁), 2-(5-mercapto-[1,3,4] oxadiazol-2-yl)-phenol) (L₂), 2-(5-mercapto-[1,3,4]thiadiazol-2-yl)-phenol) (L₃), 2-[1-(H-benzimidazol-2-yl]-5-phenyl-1Hpyrazol-3-yl]-4-methyl phenol (L₄) and 3-(2-hydroxy-5-methylphenyl- pyrazol-1-yl]-pyridin-4-yl-methanone (L₅) in N, Ndimethylformamide (DMF) have been carried out at 303, 308, 313,318 and 323 K in the solute concentration of 1×10^-2 moldm^-3.The experimental data have been used to calculate various acoustical parameters such as apparent molal volume (ϕ_v), apparent molal compressibility (ϕ_k(s)), intermolecular free length (<i>L</i>_f), specific acoustic impedance (<i>Z</i>s) and relative association (<i>R</i>_A). The results suggest the presence of molecular interactions.

The effect of temperature variation on the strength of molecular interactions has been studied and the data have been quantitatively explained in terms of solute-solute and solute-solvent interactions.