Rotational analysis of the forbidden <i>d</i>³ Δ_<i>i</i> ← <i>X</i>¹Σ⁺ absorption bands of carbon monoxide

Abstract

The forbidden d 3 Δ i –X 1 Σ + transition of CO has been observed in absorption at high resolution in the vacuum ultraviolet region. The intensity distribution in the rotational structure of the observed bands is in conformity with the assumption that the transition occurs on account of the interaction between the d 3 Δ state and a 1 Π state, presumably the A 1 Π state. Thirteen bands of the d–X system have been analyzed yielding more extensive rotational data for the d 3 Δ i state than were previously known. A discussion of the local perturbations in the d state by the A 1 Π and a 3 Π states is included.