15min:

SARA A. BEATON AND MICHAEL C. L. GERRY, Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1 .

The pure rotational spectra of ZrS and ZrO have been recorded using cavity Fourier transform microwave spectroscopy in the frequency range 9-26 GHz. The molecules were generated by laser ablation of a solid Zr rod with 0.05% of H₂S or O₂, respectively, in either argon or neon.

For ZrS, this is the first measurement of the pure rotational spectrum of the X¹⁺ state. Rotational transitions in the ground vibrational state were observed for all five Zr³²S isotopomers and for the ⁹⁰Zr³⁴S isotopomer in natural abundance. Transitions in the first excited vibrational state were measured for the 3 most abundant isotopomers and a value for the equilibrium bond length calculated. For the ⁹¹Zr³²S isotopomer nuclear hyperfine structure due to the zirconium nucleus was observed and values for eQq(⁹¹Zr) and C _I(⁹¹Zr) were determined.

The microwave spectra of the three most abundant isotopomers of Zr¹⁶O had been observed previously (1). The new results from the present work are the observations of the J=1-0 transitions for the remaining two Zr¹⁶O isotopomers and three Zr¹⁸O isotopomers. In addition, the v=1 J=1-0 transition was measured for ⁹⁰Zr¹⁶O, allowing an accurate determination of r_e. ⁹¹Zr nuclear hyperfine structure was observed for ⁹¹Zr¹⁶O and values of the hyperfine constants were determined. The hyperfine parameters for the two molecules are interpreted in terms of the electronic structure and chemical bonding.