Emission spectrum of chlorine excited in the presence of argon. Part I. The band system in the region 2600-2390 Å

Abstract

The spectrum of chlorine excited in the presence of argon has been photographed with a 21-ft. grating spectrograph in the first order. Two band systems in the region 2600-2390 Å and 2365-2239 Å are observed which appear to be respectively analogous to the 2950-2670 Å and 2660-2590 Å systems of bromine reported earlier by Venkateswarlu and Verma. The wavelengths and the wavenumbers of all the bands in the system 2600-2390 Å are given. The vibrational scheme along with the corresponding Franck-Condon parabola is also given. The analysis suggests that the lower state of the system is the ³π (O _u ⁺)state established by Elliott at 17658 cm.⁻¹ and that the upper state is at 67773 cm.⁻¹ The vibrational constants obtained arew ₀' = 246·6 cm.⁻¹,w ₀'x ₀' = 0·615 cm.⁻¹,w ₀" = 255·2 cm.⁻¹,w ₀"x ₀" = 5·5 cm.⁻¹,w ₀"y ₀" = −0·0155 cm.⁻¹ andw ₀"z ₀" = 0·00115 cm.⁻¹