Electric dichroism spectroscopy in the vacuum ultraviolet. I. Cyclobutanone, cyclopentanone, cyclohexanone, and cycloheptanone

Publisher Website
Google Scholar
Abstract
Electrochromism and electric linear dichroism have been used in a study of transitions to the second excited singlet of a series of simple cyclic ketones. The results of the work show that the transition under investigation is polarized perpendicular to the direction of the dipole moment in the ground state of cyclobutanone, cyclopentanone, cyclohexanone, and cycloheptanone, where the dipole moment changes for the transition to the second excited singlet state from ground state are found to be 1.44, 1.63, 4.30, and 4.92 D, respectively. The magnitude of the changes in dipole moment and mean polarizability support the perpendicular B2←A1,3sa1←nb2 molecular Rydberg assignment. The larger dipole moment changes for the larger compounds are attributed to ring delocalization of the positive core charges in this extravalent state, a situation that appears unfavorable in the small ring compounds.