Tc. Smith et al., Determination of the electric dipole moment and excited state Fermi contact parameter of the GeCH radical, J CHEM PHYS, 115(11), 2001, pp. 5047-5052
The germanium methylidyne (GeCH) radical has been studied at high resolutio
n by laser-induced fluorescence spectroscopy in a skimmed molecular beam. T
he radical was produced in a pulsed discharge jet source using methyltrichl
orogermane as the precursor. Single rotational lines of the (A) over tilde
(2)Sigma (+)-(X) over tilde (2)Pi (3/2) component of the 0(0)(0) band at 14
070 cm(-1) were recorded with linewidths of 35 MHz, showing resolved proto
n magnetic hyperfine splittings. The observed hyperfine splittings of 12 ro
tational lines were satisfactorily modeled by varying a single upper state
Fermi contact parameter, giving b(F) = 163(2) MHz. Optical Stark measuremen
ts were performed on the (GeCH)-Ge-74 P-11(3/2)F' = 1 hyperfine transition
and the permanent electric dipole moments determined to be mu((X) over tild
e (2)Pi) = 0.122(2) D and mu((A) over tilde (2)Sigma (+)) = 1.29(2) D. Our
ab initio predictions of the dipole moments and excited state Fermi contact
parameter are in fair agreement with experiment. The magnitudes of the det
ermined parameters are discussed based on the molecular orbitals and compar
ed to similar measurements on SiCH. (C) 2001 American Institute of Physics.