15min:

D. FORTHOMME, L. E. DOWNIE, A. D. GRANGER, A. G. ADAM, C. LINTON, D. TOKARYK, Centre for Laser, Atomic and Molecular Sciences, Physics and Chemistry Departments, University of New Brunswick, Fredericton, NB, Canada, E3B 5A3; W. S. HOPKINS, Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, U.K. OX1 3QZ.

High resolution laser induced fluorescence excitation spectra have been obtained of the origin bands of the A ~²E X ~²A₁ and B ~²A₁ X ~²A₁ transitions for two isotopologues, SrO¹²CH₃ and SrO¹³CH₃, of strontium monomethoxide. The molecules were produced by laser ablation of a strontium target rod followed by reaction with ¹²C - or ¹³C - substituted methanol seeded in helium, prior to expansion into vacuum to form a pulsed supersonic jet. The spectra were complex and more congested than those we previously reported for the isoelectronic calcium monomethoxide molecule. Rotational J assignments were established from common ground state combination differences. Definitive assignments of the K structure and of the F₁ F₂ spin rotation components of the B ~²A₁ state were, however, much harder to establish and could only be achieved using optical optical double resonance (OODR) population depletion spectroscopy. We will report the latest results and analysis and also show how, by employing OODR, we were able to resolve and quantify the very small spin rotation splitting in the ground X ~²A₁ state.