NO2 spin splittings and Landé factors around 17000 cm−1: deviation from the Curl relationship

We have measured the effective spin rotation constant and the Landé factors of the N = 1, K = 0 rotational levels of 34 2B2 vibronic levels of NO2 located in the 16578–17842 cm−1 energy range in a sufficiently high magnetic field to uncouple electron spin from rotation. The spin rotation constants are randomly distributed around zero and the Landé factors range from 2.00 (the free spin value) down to 1.80 in an apparently random fashion. In the ground state these two quantities satisfy the Curl relation. In contrast, our experiments show that this relation is not satisfied around 17000 cm−1. We discuss the origin of the breakdown of the Curl relation.