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

Abstract

The pure rotational spectrum of the asymmetric top ZrO 2 has been collected using a Fourier transform microwave spectrometer that employed a laser ablation molecular beam source. Four rotational transitions for each of five Zr 16 O 2 isotopomers have been recorded. The rotational constants of the 90 Zr 16 O 2 isotope were determined to be Aϭ19 881.352 MHzϮ0.068 MHz, B ϭ7693.895 MHzϮ0.021 MHz, and Cϭ5533.111 MHzϮ0.036 MHz. The r 0 structure was determined to possess a Zr-O bond length of 1.7710 ÅϮ0.0007 Å, and an O-Zr-O bond angle of 108.11°Ϯ0.08°. The electric dipole moment has been measured for the 90 Zr 16 O 2 isotope and found to be b ϭ26.02ϫ10 Ϫ30 C•mϮ0.07ϫ10 Ϫ30 C•m ͓7.80 DebyeϮ0.02 Debye͔. The nuclear quadrupole hyperfine structure for the 91 Zr 16 O 2 isotope has also been recorded and analyzed, yielding aa ϭ115.94 MHzϮ0.16 MHz, bb ϭϪ37.55 MHzϮ0.33 MHz, and cc ϭϪ78.39 MHz Ϯ0.16 MHz. High-level density functional theory calculations yield a structure that agrees well with the values determined experimentally. Several new transitions assigned to Zr 16 O were also recorded in the course of this study, and these were analyzed to extract values of B e , ␣ e , and ␥ e for four isotopomers.

The visible spectrum of zirconium dioxide, ZrO2

“…6 The ω 2 (287 ± 2 cm −1 ) is also consistent with the 290 cm −1 value estimated from the inertial defect. 4 As expected, ω 1 and ω 2 for theX 1 A 1 state of ZrO 2 are slightly less than ω 1 (968 ± 7 cm −1 ) and ω 2 Table IV. For theX 1 A 1 state, the computational methods overestimated the Zr-O bond length by up to 0.08 Å, while the O-Zr-O angle is rather insensitive to methodology and consistent with experiment.…”

“…R eq (X 1 A 1 )is the obtained experimental structure (1.771 Å and 108.11 • ). 4 Initially, R eq (Ã 1 B 2 ) was obtained from the ab initio predicted structure in Table IV ( …”

“…A simple self-consistent field ab initio calculation using an effective core potential supported the results. The ground state pure rotational spectra of all five isotopologues have been recorded and analyzed 4 from which a bond length, R Zr-O , of 1.7710 ± 0.0007 Å and a O-Zr-O bond angle, θ , of 108.11 ± 0.08 • were derived. In that same study the electric dipole moment, μ, was determined to be 7.80 ± 0.02 D and the harmonic bending frequency, ω 2 , was estimated as 290 cm −1 from the inertial defect.…”

A Critical Appraisal of the Experimental Data on the Molecular Structure and Spectra of Halides, Oxides, and Hydrides of the s-, d-, and f-Block Elements

“…One of these represents a major advance: the recording of the microwave spectrum of ZrO 2 giving a bond length of 1.7710 AE 0.0007 and a bond angle of 108.11 AE 0.088 for the ground-state molecule in the gas phase. [130] As the corresponding matrix-isolation experiment [87] gave an upper limit of 113 AE 58 for the bond angle while that calculated was 1128, the value of 1088 gives confidence in both the matrix data and the calculations on similar strongly bonded dioxides.…”

How a Quantum Chemical Topology Analysis Enables Prediction of Electron Density Transfers in Chemical Reactions. The Degenerated Cope Rearrangement of Semibullvalene

“…However, HfO 2 molecule shows the stretching bands in the region of 889 cm -1 (symmetric) and 820 cm -1 (asymmetric) which are in excellent agreement with the experimental values of 883 cm -1 and 814 cm -1 , respectively, reported by Lesarri et al 69 In addition, the calculated frequency for the bending mode of ZrO 2 of 304 cm -1 agrees well with the 290 cm -1 value determined from the inertial defect. 70 The most stable structures for the MO molecules (TiO( 3 ∆), ZrO( 1 Σ + ), and HfO ( 1 Σ + ))…”