10min:

P. CROZET, A. J. ROSS, Laboratoire de Spectrométrie Ionique et Moléculaire (UMR 5579 CNRS), Bâtiment A. Kastler, Université Lyon I, Domaine Scientifique de la Doua, 69622 Villeurbanne Cedex, France; C. LINTON, M. J. DICK, Physics Department, University of New Brunswick, Fredericton, NB, Canada E3B 5A3; A. G. ADAM AND W. S. HOPKINS, Department of Chemistry, University of New Brunswick, Fredericton, NB, Canada E3B 6E2 .

Laser excitation spectra of the A ~²E X ²A₁ system of four isotopomers of calcium methoxide were recorded at the University of New Brunswick. The radicals were produced in a laser ablation source, using a 1.2 % mixture of methanol (¹²CH₃OH, ¹³CH₃OH, ¹²CD₃OD and ¹³CD₃OD) in He as a precursor. High resolution spectra were recorded in the range 15870~-~15985 cm^-1 and 16320~-~16500 cm^-1(F.W.H.M. 250 MHz) using a tunable, single-mode cw dye laser (CR 699 + autoscan), operating with DCM and Kiton red dyes.

The transitions were assigned to the two spin-orbit components A ~²E_3/2 X ~²A₁ and A ~²E_1/2 X ~²A₁ of the origin band, and of a band with v'₄(Ca-[OCH₃] stretch)~=~1. Resolved J and K structures are observed. The analysis used an effective Hamiltonian given in the literature. The fits build on earlier work on the main isotopomer, and include spectroscopic data for the B X system given in the literature. We obtain structural parameters for the calcium monomethoxide radical from the rotational constants obtained from the different isotopomers.