A new band system of copper hydride in the far ultraviolet

Abstract

The absorption spectrum of CuH has been studied in the region 2270–2740 Å. The lines can be grouped into 22 bands of a 1Σ+–1Σ+ transition, involving the vibrational levels ν = 3,4,..., 11 of the excited state, E1Σ+.In the E1Σ+ state the molecule has a large internuclear distance and an anomalous dependence of the vibrational quanta and the rotational constants on the vibrational quantum number. E1Σ+ resembles the first excited states of the alkali hydrides in which the anomalous behavior is caused by an interaction with an ionic state.There are numerous perturbations by a 3II state. Rough values for the rotational constants, the spin–orbit coupling constant, and the zero positions of two vibrational levels of this state have been estimated from the positions of the perturbation maxima.