THE VISIBLE EMISSION SPECTRUM OF Cl2+1

Two visible emission band systems attributed to the ionized molecule Cl2+ were studied using the second order of a 21-ft concave grating spectrograph (dispersion 1.25 Å/mm). Rotational analyses have been carried out for six bands of system I and six of system III for which new vibrational analyses have recently been proposed by Haranath and Rao. The rotational analyses of the bands of these two systems are consistent with the vibrational assignments. Rotational constants for the upper and lower states of the two systems have been derived. Both the vibrational and rotational analyses of systems I and III indicate case (c) 1/2–1/2 and 3/2–3/2 transitions respectively for the two systems. Potential energy curves are drawn for the upper and the lower states of each of the two systems. The lower states dissociate into a normal Cl (2P) + Cl+(3P) while the upper states dissociate into a normal Cl (2P) + an excited Cl+ (1D). It is suggested that the lower state of system 111 is probably the normal state of Cl2+ from theoretical and experimental evidence.