High-resolution Fourier transform emission spectroscopy of the (A)over-tilde2Πi-(X)over-tilde2Πi band of the OCS+ ion

High resolution Fourier transform emission spectroscopy of the (A) over tilde (2)Pi(i)-(X) over tilde (2)Pi(i) band of the OCS+ ion was performed in the UV region to observe the nu(1) (CO stretch) progression bands (upsilon(1) = 0 -> 2-5) for both the Omega = 3 = 2 and 1/2 spin components. Accurate molecular constants including the rotational constants, B-0 = 0.194 765(13) and 0.187 106(13) cm(-1), and the spin-orbit interaction constants, A(0) = 381.0(56) and -126.5(56) cm(-1), were determined for the (X) over tilde (2)Pi and (A) over tilde (2)Pi states, respectively, by the simultaneous analysis of the observed progression bands. The CO bond length (r(CO) = 1.2810 angstrom) for the (A) over tilde (2)Pi state, derived from the rotational constant B-0 and Franck-Condon factors, is longer by 0.1756 angstrom than that (1.1054 angstrom) for the (X) over tilde (2)Pi state, while the CS bond length for the (A) over tilde (2)Pi state is shorter by 0.0905 angstrom than that for the (X) over tilde (2)Pi state. Pure rotational transition frequencies in the ground (X) over tilde (2)Pi state are predicted, as well as transition frequencies of the nu(1) fundamental band, with the present molecular constants. Published by AIP Publishing.