Knowledge Bank

Laser excitation spectra of the $A\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}E\leftarrow X\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A1$ 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 $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CH3OH,13CH3OH,12CD3OD$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CD3OD$) in He as a precursor. High resolution spectra were recorded in the range $15870-15985cm-1$ and $16320-16500cm-1$(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 $A\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}E3/2\leftarrow X2A1$ and $A2E1/2\leftarrow X2A1$ of the origin band, and of a band with v'$\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}(Ca-[OCH3]stretch)=1$. Resolved J and K structures are observed. The analysis used an effective Hamiltonian given in the $literaturea$. The fits build on earlier work on the main $isotopomerb$, and include spectroscopic data for the $B\leftarrow X$ system given in the $literature.cd$ We obtain structural parameters for the calcium monomethoxide radical from the rotational constants obtained from the different isotopomers.