Dielectric, FT-IR and UV–vis spectroscopic studies on the fluid structure of diisopropyl ether–caprylic acid mixture

Using experimental dielectric data, the structure probing parameters such as Kirkwood-correlation factor, excess permittivity and excess Gibb’s free energy of mixing for the binary mixture of diisopropyl ether with caprylic acid have been calculated over the entire composition range and at four different temperatures 303, 308, 313 and 318 K. These parameters are interpreted in terms of molecular association and dipolar orientation in the mixture. The results of FT-IR and UV–vis spectroscopic studies are also presented. In the binary mixture, two CO absorption bands of caprylic acid are observed in the FTIR spectrum. The structure of the complex molecule has been optimized using density functional theory. The dipolar alignment given by UV–vis spectrum compliments that suggested by dielectric studies.