Journal of Chemical Physics, Vol.106, No.12, 4869-4876, 1997
High-Resolution Laser Spectroscopy of the Cs-2-C-(1)Pi(U) State - Perturbation and Predissociation
High resolution spectra of the C-1 Pi(u)(upsilon’,J’)-X(1) Sigma(g)(+)(upsilon ",J ") transitions of the CS2 molecule were measured by the technique of Doppler-free optical-optical double resonance polarization spectroscopy. A number of C-1 Pi(u)(upsilon greater than or equal to 13,J) levels were found to be strongly perturbed. Transitions to the perturbing levels were observed, and the energy shifts of e and f levels of the C-1 Pi(u), state were studied and identified as originating from perturbations between the C-1 Pi(u) and (2)(3) Pi(1u) states. Molecular constants of the C-1 Pi(u)(upsilon = 7-18) and (2)(3) Pi(1u)(upsilon = upsilon(0) - upsilon(0) + 6) levels were determined. Line splittings were observed for the transitions to the C-1 Pi(u)(upsilon = 13 and 14,Jf) levels which were identified as hyperfine splittings originating from additional interaction with the state. Remarkable line broadenings were observed in the transitions to the C-1 Pi(u)(upsilon > 15,Je and f) levels, and were identified as originating from the predissociation through the dissociative (2)(3) Sigma(u)(+) state. The repulsive potential curve of the (2)(3) Sigma(u)(+) State was estimated to cross that of the C-1 Pi(u) state around the outer turning point of the C-1 Pi(u)(upsilon = 16 or 17) level.
Keywords:POLARIZATION SPECTROSCOPY;CS2