THE MILLIMETER-WAVE SPECTRUM OF THE MGOH RADICAL (X2-SIGMA+)

The pure rotational spectrum of the ground electronic state (X 2-SIGMA+) of the MgOH radical has been observed using millimeter/sub-millimeter direct absorption spectroscopy, as well as that of MgOD, and the less abundant magnesium isotopically-substituted species (MgOH)-Mg-25 and (MgOH)-Mg-26. The free radicals were created in a Broida-type oven by the reaction of metal vapor with hydrogen peroxide. The spin-rotation splitting was readily observed in these data; however, the hyperfine structure was only resolved for (MgOH)-Mg-25. The rotational and spin-rotation constants of the radicals have been determined from a non-linear least-squares fit using a 2-SIGMA Hamiltonian. The Mg-25 hyperfine constants are also estimated.