Knowledge Bank

Excitation spectra of the new molecules YOH and YOD have been recorded in the 500-625 nm wavelength region by laser-induced fluorescence, following reaction of laser-ablated yttrium with $H2O$ or $D2O$ under supersonic jet-cooled molecular beam conditions. Rotational analyses of $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +-X¯1\Sigma +$ bands near 540 nm at high resolution gave the following substitution structure for the ground state: [ \tilde{X}\Sigma^{-}: r(Y-O) = 1.948; {\textrm{\AA}};; r(O-H) = 0.92_{1} ;\textrm{\AA}. ] Wavelength-resolved fluorescence spectra have given the ground state vibrational frequencies [ YOH (YOD): \nu^{2},; bend = 314 (247);cm^{-1}; \nu^{3},; YO;stretch = 674 (654)cm^{-1} ] No evidence for the $\nu 1$ (OH stretch) mode was observed. Very complicated weak structure at the long wavelength end may possibly correspond to a singlet-triplet transition.