15min:

MATTHEW P. BUCCHINO, Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721; AND LUCY M. ZIURYS, Department of Chemistry and Biochemistry, Department of Astronomy, and Steward Observatory, University of Arizona, Tucson, Arizona 85721.

Sub-millimeter spectra of CaH (X^{2 +}), MgH (X^{2 +}), and ZnH (X^{2 +}) have been measured in the sub-mm/THz regime (500-805 GHz) using direct-absorption methods. All species were produced by the reaction of metal vapor with H₂ under DC discharge in a Broida-type oven. Because of efficient molecule production, spectra of ²⁶MgH, ⁶⁶ZnH, ⁶⁸ZnH and ⁷⁰ZnH could be recorded in their natural abundance as well, with high signal-to-noise. Additionally, the N = 0 1 and N = 1 2 transitions of ²⁵MgH and ⁶⁷ZnH were measured. Fermi contact, dipolar, and quadrupole constants for the ²⁵Mg and ⁶⁷Zn nuclei have been accurately determined for the first time in the gas phase, and are in good agreement with previous ESR studies. The hyperfine constants suggest a substantial amount of covalent character is present in metal hydrides.