HYPERFINE-STRUCTURE IN THE ELECTRONIC-SPECTRA OF THE CDH AND CDCH3 RADICALS

Magnetic hyperfine interactions in the ground and first excited states of CdH and CdCH3 were studied using high resolution electronic spectr oscopy. Hyperfine splittings associated with the H nucleus were observ ed in the X state of CdH; hyperfine splittings associated with Cd-111 and Cd-113 were observed in both the ground and first excited states o f CdH and CdCH3. The hyperfine parameters of CdH were found to be simi lar to the corresponding parameters of CdCH3. Comparison of the ground state molecular hyperfine constants with values determined in an Ar m atrix electron paramagnetic resonance (EPR) study [L. B. Knight, Jr. a nd UT. -Weltner, Jr., J. Chem. Phys. 55, 2061 (1971)] indicates clearl y a shift of unpaired electron spin density towards Cd, in the matrix. The excited state molecular hyperfine constants indicate that the unp aired electron essentially resides in a Cd 5p pi orbital.