Infrared and dielectric studies of chloroform as proton donor in hydrogen-bond formation
Date of Original Version
Infrared absorption bands of free and associated species of deuterochloroform were observed in binary solutions (with triethylamine). Temperature-dependent spectra were used to calculate the equilibrium constants at various temperatures and the heat of formation of the complex molecule. A value of 0.133±3% liter mole-1 was obtained for the equilibrium constant at 25°C. The heat of formation of the deuterochloroform-triethylamine complex was determined to be 4.0 kcal mole -1. The dielectric constant shows a substantial increase over the value predicted by Onsager's theory. This indicated that the associated complex possesses a large dipole moment. In conjunction with the infrared data, the dipole moment of the associated molecule was evaluated as 3.15×10 -18±10% cgs units. Similar infrared and dielectric measurements were carried out on deuterochloroform-acetonitrile mixtures. No strong hydrogen bonding was detected by either method.
The Journal of Chemical Physics
Khare, B. N., S. S. Mitra, and G. Lengyel. "Infrared and dielectric studies of chloroform as proton donor in hydrogen-bond formation." The Journal of Chemical Physics 47, 12 (1967): 5173-5179. doi:10.1063/1.1701775.