Heteremolecular Structure Formation in Binary Solutions of Dimethylformamide-Water and Tetrahydrofuran-Water: Ftir and Refractometry

Along with other works that employ a more complex and time-consuming approach to analyse the formation of heteromolecular structures in aqueous solutions of dimethylformamide and tetrahydrofuran, we propose a new technique based on the combined use of refractometry and IR spectroscopy. The formation of intermolecular complexes is analysed by measuring the excess refractive index and the ratio of OH absorption bands of bound molecules to those of free ones in the concentration range of 0÷1 mole fraction of components. It has been shown that the formation of heteromolecular structures occurs within a narrow concentration range of 0.3 to 0.4 mole fractions of dimethylformamide and tetrahydrofuran, which corresponds to the maximum number of realized hydrogen bonds in the dimethylformamide-water and tetrahydrofuran-water systems.