Fourier transform microwave spectroscopy of jet-cooled ZrO2 produced by laser vaporization

The pure rotational spectrum of the asymmetric top ZrO2 has been collected using a Fourier transform microwave spectrometer that employed a laser ablation molecular beam source. Four rotational transitions for each of five (ZrO2)-O-16 isotopomers have been recorded. The rotational constants of the (ZrO2)-Zr-90-O-16 isotope were determined to be A = 19 881.352 MHz +/- 0.068 MHz, B = 7693.895 MHz +/- 0.021 MHz, and C = 5533.111 MHz +/- 0.036 MHz. The r(0) structure was determined to possess a Zr-O bond length of 1.7710 Angstrom +/- 0.0007 Angstrom, and an O-Zr-O bond angle of 108.11 degrees +/- 0.08 degrees. The electric dipole moment has been measured for the (ZrO2)-Zr-90-O-16 isotope and found to be mu(b) = 26.02x10(-30) C.m +/- 0.07x10(-30) C.m [7.80 Debye +/- 0.02 Debye]. The nuclear quadrupole hyperfine structure for the (ZrO2)-Zr-91-O-16 isotope has also been recorded and analyzed, yielding chi(aa) = 115.94 MHz +/- 0.16 MHz, chi(bb) = -37.55 MHz +/- 0.33 MHz, and chi(cc) = -78.39 MHz +/- 0.16 MHz. High-level density functional theory calculations yield a structure that agrees well with the values determined experimentally. Several new transitions assigned to (ZrO)-O-16 were also recorded in the course of this study, and these were analyzed to extract values of B-e, alpha(e), and gamma(e) for four isotopomers. (C) 1999 American Institute of Physics. [S0021-9606(99)01432-4].