NUCLEAR HYPERFINE STRUCTURE IN $\tilde{A} \leftarrow \bar{X}$ TRANSITIONS OF Cd-R (R=H,$CH_{3}$)

Abstract

Jet cooled, high resolution ($< 140$ MHz) spectra have been recorded for $\bar{A} ^{2}E_{1/2} \leftarrow \bar{X} ^{2}A_{1}$ transition of $CdCH_{3}$ and for both spin-orbit components of the $A ^{2}\Pi \leftarrow X,^{2}\Sigma^{+}$ transition of CdH. Hyperfine structure due to $^{111}Cd$ and $^{113}Cd$, both with $1 = 1/2$, is observed in both species. Additionally, CdH reveals hydrogen hyperfine splitting. The spectra from both species have been fit to a model that includes Fermi contact, electronic-nuclear dipolar and nuclear spinelectronic orbit interactions. The fitted parameters are compared to previous matrix ESR $studies^{1}$ of X CdH and provide further support for the $\tilde{A} \leftarrow \bar{X}$ transition being principally metal centered $(Cd 5p_{x,y} \leftarrow 5s)$ in both of these species.