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Volume-related properties of thiophene and furan-2-carboxaldehyde phenylhydrazone derivatives in DMSO: A discussion about non-intrinsic contribution

Abstract:

An analysis of the experimental and theoretical non-intrinsic contribution to the limiting partial molar volume, θ, of thiophene- and furan-2-carboxaldehyde phenylhydrazone, 4-nitrophenylhydrazone and 2,4-dinitrophenylhydrazone derivatives - henceforth referred as PHT, NHT, DHT, PHF, NHF and DHF, respectively - in dimethylsulfoxide is presented. A refractometric method to determine θ was proposed, which was able to successfully reproduce the method based on high-precision densitometry measurements at T = 293.15 K. No general trend of θ with the molecular size was observed. The theoretical values were calculated within the Scaled Particle Theory framework using both the Kharakoz equation and the Lee-Graziano model with a volumetric contribution from attractive interactions. The values of θ of the more rigid systems, were better represented by the Lee-Graziano model. The attractive term was examined considering the (solute + solvent) separation distance suggesting a possible contribution of specific interactions.