COMPARISON OF MOLECULAR DIPOLE MOMENTS DETERMINED BY VAPOR PHASE AND SOLID STATE STARK SPECTROSCOPY
Date
1975
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The change in molecular dipole moment on electronic excitation has been determined by Stark spectroscopy at 4.$2^{\circ} K$, using a Lorentz approximation to calculate the local field, for a number of aromatic molecules in non-polar solvents: p-fluoroaniline in durene, p-fluoroaniline in p-dime thoxybenzene, and aniline in durene. These values differ appreciably (in some cases by more than 100\%) from the values reported for the vapor $phase.^{1}$ These differences can be attributed to the inadequacy of the Lorentz field approximation, to the polarization of the medium by the permanent and the induced dipole moment of the guest molecule, and to the modification of the molecular geometry and electronic charge distribution by the crystal field. Experiments on some halobenzenes in 3-methylpentane glass at $77^\circ K$ using the Stark modulation technique are underway, and the results on these systems also will be presented and compared with the vapor phase $results.^{2}$
Description
$^{1}$K.-T. Huang and J. R. Lombardi, J. Chen. Phys. 51, 1228 (1969). J. R. Lombardi, J. Chem. Phys. 50, 3780 (1969). $^{2}$K.-T. Huang and J. R. Lombardi, J. Chem. Phys. 52, 5613 (1970). M. J. Janiak, A, Hartford, JR., and J. R. Lombardi, J- Chem. Phys 54, 2449 (1971). C. Y. Wu and J, R. Lombardi, J, Chem. Phys. 55, 1997 (1971).""
Author Institution: Department of Chemistry, State University of New York
Author Institution: Department of Chemistry, State University of New York