Rotational Analysis of the PH and PD A3Πi–X3Σ− Band Systems

Abstract

PH and PD radicals have been produced in a Schüler type discharge through PH3 and PD3. Besides the already known (0–0) bands of PH and PD, new bands, namely the (0–1) band of PH and the (1–0) and (1–1) bands of PD have been photographed in emission, under high resolution. Rotational analyses have been performed for these six bands and also for the (1–0) band of PH analyzed earlier by Legay in absorption. The 3Π and 3Σ states fine structure has been interpreted by a simple model, which includes spin–spin, and second-order spin–orbit interactions and also centrifugal distortion effects both on rotational and spin–orbit coupling parameters. The ν dependence of the different molecular parameters has been examined and interpreted where possible.