Knowledge Bank

An intense pulsed supersonic moleculer beam sample of $CaCH3$ was produced using a laser ablation/reaction source. The high resolution (50 MHz FWHM) laser induced fluorescence spectrum of the ($K\prime =1-K0=0)A~2E-X~2A1$ band system (origin = $14743cm-1$) was recorded and fitted to produce an improved set of spectroscopic parameters. The resultant parameters were in agreement with those obtained in a previous Doppler limited $studya$. A number of the transitions involving the lowest $J$ levels were also recorded in the presence of variable static electric field. The Stark shifts and splittings were fitted to obtain dipole moments of 2.62(3) D and 1.69(1) D for the $X~2A1$ and $A¯2E$ states, respectively. The dipole moments were predicted using an electrostatic polarizability $modelb,c$ that had successfully predicted the dipole moments of CaCCH . The predicted values, 1.78 D $X¯2A1$ and 1.20 D $A¯2E$, are in reasonable agreement with experiment.