Theoretical calculations of the molecular properties of a CFC substitute: CHCl 2CF 3 (HCFC123)

Abstract

Ab initio, density functional and density functional self-consistent reaction field calculations (SCRF) for CHCl 2CF 3 (HCFC-123) are reported. Equilibrium geometry is in excellent agreement with experimental data. The gas phase dipole is 1.3 D in very good agreement with experiment (1.36 D). The dipolar polarizability is 56.9 a o 3 and the experimental value is 54.4 a 3 o. SCRF calculations based on the SCIPCM model predict that solvation of HCFC-123 in a dielectric medium with a dielectric constant corresponding to that of pure liquid ( ε=7) increases the dipole moment relative to the gas phase value by ∼25%. This prediction is consistent with recent estimations of the effective dipole moment in the liquid from dielectric measurements. Density functional vibrational frequencies are in very good agreement with recent experimental data. Electrostatic interaction with a dielectric environment induces a blue shift of the frequency related to the C–H stretch vibrational mode.