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 Zr16O2 isotopomers have been recorded. The rotational constants of the 90Zr16O2 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 r0 structure was determined to possess a Zr–O bond length of 1.7710 ű0.0007 Å, and an O–Zr–O bond angle of 108.11°±0.08°. The electric dipole moment has been measured for the 90Zr16O2 isotope and found to be μb=26.02×10−30 C⋅m±0.07×10−30 C⋅m [7.80 Debye±0.02 Debye]. The nuclear quadrupole hyperfine structure for the 91Zr16O2 isotope has also been recorded and analyzed, yielding χaa=115.94 MHz±0.16 MHz, χbb=−37.55 MHz±0.33 MHz, and χcc=−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 Zr16O were also recorded in the course of this study, and these were analyzed to extract values of Be, αe, and γe for four isotopomers.