Rotational band contour analyses in the 3062 Å system of p-fluoroaniline and the 2847 Å system of p-fluorophenol

Abstract

The origin bands of the 3062 å system of p-fluoroaniline and the 2847 å system of p-fluorophenol have been rotationally analysed by the asymmetric rotor band contour method. They are both type B bands of prolate asymmetric tops which require the electronic assignments of the systems to be ¹ B ₂-A ₁. The excited state rotational constants have been obtained in both cases and show that there is a contraction from the ground to the excited state along the long in-plane axis: the contraction is greater in p-fluoroaniline than in p-fluorophenol. The rotational constants of p-fluoroaniline could not be obtained sufficiently accurately to provide any information on the configuration of the amino group. The rotational origin of the 3062 å band of p-fluoroaniline is at 32653·3 ± 0·1 cm^-1 and that of the 2847 å band of p-fluorophenol is at 35115·9 ± 0·1 cm^-1.