Author Institution: Department of Physics, The Ohio State University, Columbus Ohio, 43210-1106, USA; Department of Physics and Centre for Laser, Atomic, and; Molecular Sciences, University of New Brunswick, P.O. Box 4400; Fredericton NB E3B 5A3, Canada; Canadian Light Source, Inc., University of Saskatchewan; Saskatoon, SK, Canada

The 000 bands of the A2E–X2A1 and B2A1–X2A1 electronic transitions of SrO12CH3 and the B2A1–X2A1 transition of SrO13CH3 have been recorded at high resolution using a laser ablation jet source. The optical–optical double resonance population depletion technique was used to facilitate the assignment of the spectra. Rotational levels with K=0, ±1 in the X2A1 and B2A1 states and K=0, 1 and 2 in the A2E state have all been characterised. A perturbation affecting the B2A1 state caused a reversal of the ordering of the spin-rotation components, F1 and F2, in the SrO12CH3 isotopologue. This required the introduction of a modified rotational constant Bmod, affecting only the K=1, F2 component of the B2A1 state, in order to model the SrO12CH3 data in a global fit of the A2E–X2A1 and B2A1–X2A1 transitions.

Author Institution: Centre for Laser, Atomic, and Molecular Sciences and Physics Department, 8 Bailey Dr., University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada E3B 5A3; Centre for Laser, Atomic, and Molecular Sciences and Chemistry Department, 30 Dineen Dr., University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada E3B 5A3

The 000 band of the A˜2Π-X˜2Σ+ transition of MgC4H has been recorded at high resolution using laser-induced fluorescence. The molecules were produced using an ablation source by the reaction of magnesium and ∼10% acetylene seeded in helium. The rotationally-resolved high-resolution data were fitted to obtain rotational and fine structure parameters for both states. The centrifugal distortion, upper state Λ-doubling and ground state spin-rotation splitting parameters were all found to be negligible and the reasons for this are investigated and discussed. The 301 band heads of the A˜2Π-X˜2Σ+ transition of MgC6H were obtained but the rotational structure was not resolved.