Journal of Physical Chemistry A, Vol.110, No.19, 6256-6260, 2006
Study on the photodissociation spectra of CS2+ via (B)over-tilde(2)Sigma(+)(u) and (C)over-tilde(2)Sigma(+)(g) electronic states
The photodissociation spectra of CS2+ ions via B-2 Sigma(+)(u) and C-2 Sigma(+)(g) electronic states have been studied by using two-photon excitation, where the parent CS2+ ions were prepared by [3 + 1] REMPI (resonance-enhanced multiphoton ionization) at 483.2 nm from the jet-cooled CS2 molecules. The [1 + 1] photodissociation spectrum of CS2+ via the B-2 Sigma(+)(u)(v(1)v(2)0) <- (XIIg,3/2)-I-2(000) transition was obtained by scanning the dissociation laser in the wavelength range of 270-285 nm and detecting the signal of both S+ and CS+. The [1 + 1] photodissociation spectra of CS2+ were obtained by fixing the first dissociation laser at 281.94 or 277.15 nm to excite the B-2 Sigma(u)(+) (000 or 100) <- (XIIg,3/2)-I-2(000) transitions and scanning the second dissociation laser in the range of 606-763 nm to excite C-2 Sigma(+)(g)(v(1)v(2)0) <- B-2 Sigma(+)(u)(000,100) transitions. New spectroscopic constants of v(1) = 666.2 +/- 2.5 cm(-1), v(2) = 363.2 +/- 1.9 cm(-1), chi(11) = -5.5 +/- 0.1 cm(-1), chi(22) = 1.6 +/- 0.1 cm(-1), chi(12) = -8.6 +/- 0.2 cm(-1), and k(122) = 44.9 +/- 2.5 cm(-1) (Fermi resonance constant) for the C-2 Sigma(+)(g) state are deduced from the [1 + 1] photodissociation spectra. On the basis of the [1 + 1] and [1 + 1] photodissociation spectra, the wavelength and level dependence of the product branching ratios CS+/S+ has been found and the dissociation dynamics of CS2+ ions via B-2 Sigma(+)(u) and C-2 Sigma(+)(g) electronic states are discussed.