THEORETICAL CALCULATIONS OF THE MOLECULAR-PROPERTIES OF A CFC SUBSTITUTE - CHCL2CF3 (HCFC-123)

Ab initio, density functional and density functional self-consistent r eaction field calculations (SCRF) for CHCl2CF3 (HCFC-123) are reported . Equilibrium geometry is in excellent agreement with experimental dat a. The gas phase dipole is 1.3 D in very good agreement with experimen t (1.36 D). The dipolar polarizability is 56.9 a(0)(3) and the experim ental value is 54.4 a(0)(3). SCRF calculations based on the SCIPCM mod el predict that solvation of HCFC-123 in a dielectric medium with a di electric constant corresponding to that of pure liquid (epsilon = 7) i ncreases the dipole moment relative to the gas phase value by similar to 25%. This prediction is consistent with recent estimations of the e ffective dipole moment in the liquid from dielectric measurements. Den sity functional vibrational frequencies are in very good agreement wit h recent experimental data. Electrostatic interaction with a dielectri c environment induces a blue shift of the frequency related to the C-H stretch vibrational mode. (C) 1998 Elsevier Science B.V. All rights r eserved.