5314027776

POSTER SESSION. H33

HIGH RESOLUTION STUDY OF THE B²£⁺- X²E⁺ (0,0,0 - 0,0,0) BAND OF YTTRIUM IMIDE (Y^I4NH, Y^ł5NH, AND Y^MND).

ZYGMUNT ,). JAKUBEK AND BENOIT SIMARD, Steacie In-stitute for Molccular Sciences, National Research Council of Canoda. Ot-tawu. ON, Canada KlA 0R6; HIDEAKI NIKI, Electncal and Electron-ics Engineermg, Fukui U mv er sity, Fukui-shi, Fukui 910, .lapan; WALTER J. BALFOUR. Department of Chemistry_t University of Yictona, Victoria, BC, Canada V8W 3V6.

Results of high rcsolution molecular bc&m studies of the B²£⁺— X²£⁺ (0,0,0 - 0.0.0) transition in yttrium imideare reportod. Threc isotopomers (Y^ł4NH, Y^,5NH. and Y^l4ND) are investigated. The YNH molecules are produced by laser ablation of yttrium motał in the presence of aminonia dilutcd in helium gas (1-2%). Molecules are cx<:itcd l>y a ring dye laser and laser induced fluori?sccnce is detected. The spectra are very complicated due to multiple porturbations in the upper State and nuclcar magnetic hyperfine structure in the ground State. The hyperfine structure arrises froin interaction of an unpaired o electron with the ^H ‘Y nucleus. Sorne of the perturbers are assigned to vibronic States originating froin the A' ²A and A²n electronic States and others are treated as effcctive perturbers. The spectra are deperturbed and accurate molccular constants for the B²£* (0.0.0) and X²E“ (0,0,0) States as well as sonie of the perturbers are obtained. The yttrium imide is found to have the linear Y-N-H structure in both the    and X²£⁺ States. The bond

lengths in the ground State are: rys = 0.18780 nm and rv// = 0.10022 nin. The hyperfine parameters are determined and coinpared wit h those of an isoclectronic molwulc, YO.