Mikrowellenspektrum, Hinderungspotential der internen Rotation und teilweise r₀-Struktur des para-Chlortoluols

Abstract

The rotational microwave spectra of the two chlorine isotopic species of para-chlorotoluene have been measured in the region from 8.4—11.3 GHz. Values for the rotational constants and for the nuclear quadrupole constants have been determined. The barrier to internal rotation of the methyl group is V 6 = 13.93 ± 0.04 cal/mole. Two structural parameters have been estimated, namely 1.39 4 Å for the average ring C — C distance and 1.74 ± 0.01 A for the C — Cl distance.