Hyperfine structure in the electronic spectra of the CdH and CdCH3 radicals

Abstract

Magnetic hyperfine interactions in the ground and first excited states of CdH and CdCH3 were studied using high resolution electronic spectroscopy. Hyperfine splittings associated with the H nucleus were observed in the X state of CdH; hyperfine splittings associated with 111Cd and 113Cd were observed in both the ground and first excited states of CdH and CdCH3. The hyperfine parameters of CdH were found to be similar to the corresponding parameters of CdCH3. Comparison of the ground state molecular hyperfine constants with values determined in an Ar matrix electron paramagnetic resonance (EPR) study [L. B. Knight, Jr. and W. Weltner, Jr., J. Chem. Phys. 55, 2061 (1971)] indicates clearly a shift of unpaired electron spin density towards Cd, in the matrix. The excited state molecular hyperfine constants indicate that the unpaired electron essentially resides in a Cd 5pπ orbital.

The isotopic dependence of the spin–rotation interaction: the rotational spectrum of cadmium hydride in its X2Σ+ state

“…In Table 3, we compare our hyperfine parameters with those determined in the earlier gas-phase work of Tan et al [6]. Our values agree well with the earlier results, but are about an order of magnitude more accurate.…”

“…They resolved the fine structure, but did not observe any hyperfine splittings. Tan et al [6] recorded high-resolution spectra of the A 2 P-X 2 R þ (0,0) band around 440 nm. They determined values for the spin-rotation and hyperfine parameters of the two states.…”

Multi-isotopologue analyses of new vibration–rotation and pure rotation spectra of ZnH and CdH

“…These calculations further confirmed the experimental assignments of the A 2 P, B 2 R + , and C 2 R + states [33][34][35]. Hyperfine structure, K-doubling and lifetimes of ZnH and CdH have been measured by laser-induced fluorescence spectroscopy [36,37] and by matrix-isolation electron spin resonance (MI-ESR) techniques [38][39][40]. Low resolution infrared absorption spectra of ZnH, ZnD, CdH, and CdD trapped in solid argon, neon, and hydrogen matrices have also been recorded [41,42].…”

Vibronic spectroscopy of unsaturated transition metal complexes: CrC2H, CrCH3, and NiCH3

“…These include the transition metal methylidynes TiCH, 23 VCH, 24 NbCH, 25 TaCH, 26 and WCH, 27 the dicarbide YC 2 , 28,29 the acetylide YbCCH, 30 and the cyanides CuCN 31 and NiCN. 32 Spectroscopic studies of filled ͑or empty͒ d-subshell organometallic radicals such as MgCH 3 , 33 CaCH 3 , 34 -36 SrCH 3 , 34,37 BaCH 3 , 38 ZnCH 3 , 39,40 CdCH 3 , 39,41,42 MgCCH, 43,44 CaCCH, [45][46][47] SrCCH, 45,48 NaCH, 49 KCH, 49 and CaC 5 H 5 50 have been very successful and abundant, but these molecules generally lack the connection to catalytic chemistry that is a primary motivation for the study of transition metal organometallic radicals.…”