New rovibrational analysis of A–X absorption spectrum of Cl2+

Two bands of the A2Πu–X2Πg spectrum of 35Cl2+ and one band of 35Cl37Cl+ in the region between 16820 and 17350cm−1 have been recorded using optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy. It is the first time to report the rotational analyses of these bands. The little magnetic enhancement of these lines confirms the identity of these bands as due to the Ω=1/2 component of the electronic transition in spite of the paramagnetic feature of Cl2+ molecule.