THE ROTATIONAL SPECTRA AND HYPERFINE CONSTANTS OF ZrS AND ZrO.

(1) R.D. Suenram, F.J. Lovas, G.T. Fraser and K. Matsumura, J. Chem. Phys. 92, 4725-4733 (1990).Author Institution: Department of Chemistry, The University of British ColumbiaThe 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 $H_{2}S$ or $O_{2}$, respectively, in either argon or neon. For ZrS, this is the first measurement of the pure rotational spectrum of the $X^{1}\Sigma^{+}$ state. Rotational transitions in the ground vibrational state were observed for all five $Zr^{32}S$ isotopomers and for the $^{90}Zr^{34}S$ 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 $^{91}Zr^{32}S$ isotopomer nuclear hyperfine structure due to the zirconium nucleus was observed and values for $eQq(^{91}Zr)$ and $C_{T}(^{91}Zr)$ were determined. The microwave spectra of the three most abundant isotopomers of $Zr^{16}O$ 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 $Zr^{16}O$ isotopomers and three $Zr^{16}O$ isotopomers. In addition, the $v = 1 J = 1 - 0$ transition was measured for $^{90}Zr^{16}O$, allowing an accurate determination of $r_{c}. ^{91}Zr$ nuclear hyperfine structure was observed for $^{91}Zr^{16}O$ 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