Partial Molar Volumes of N,N′-1,2-Ethyl-bis(salicyladimine) Schiff Base (Salen) in Organic Solvents at T= (283.15 to 318.15) K.

Densities of N,N′-1,2-ethyl-bis(salicyladimine) Schiff base (salen) in dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), dichloromethane (CH2Cl2), and chloroform (CHCl3) binary mixtures have been measured in dilute concentration regions of salen at T= (283.15 to 318.15) K under ambient pressure. Apparent molar volumes, Vϕ, and standard partial molar volumes, Vϕ0, have been calculated from the measured densities. The Vϕ0values in DMSO have larger values corresponding to the high polarity of this solvent. The results show that their values would be increased slightly with an increase in temperature. The partial molar expansivities, Eϕ0, and the isobaric thermal expansion coefficients, α*, have been calculated from the temperature dependence of Vϕ0values. The Hepler’s constant values, (∂2Vϕ0/∂T2)p, were found to be positive or very small and negative which indicate that salen Schiff base is predominately a structure maker in all organic solvents studied. [ABSTRACT FROM AUTHOR]