Zinc oxide and its anion: A negative ion photoelectron spectroscopic study

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.477505· OSTI ID:663695

Fancher, C A; de Clercq, H L; Thomas, O C; Robinson, D W; Bowen, K H ^[1]

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1. Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

We have recorded, assigned, and analyzed the photoelectron spectrum of ZnO{sup {minus}}. The adiabatic electron affinity (E.A.{sub a}) of ZnO and the vibrational frequencies of both ZnO and ZnO{sup {minus}} were determined directly from the spectrum, with a Franck{endash}Condon analysis of its vibrational profile providing additional refinements to these parameters along with structural information. As a result, we found that E.A.{sub a}(ZnO)=2.088{plus_minus}0.010thinspeV, {omega}{sub e}(ZnO)=805{plus_minus}40thinspcm{sup {minus}1}, {omega}{sub e}(ZnO{sup {minus}})=625{plus_minus}40thinspcm{sup {minus}1}, and that r{sub e}(ZnO{sup {minus}}){gt}r{sub e}(ZnO) by 0.07 {Angstrom}. Since our measured value of E.A.{sub a}(ZnO) is 0.63 eV larger than the literature value of E.A.(O), it was also evident, through a thermochemical cycle, that D{sub 0}(ZnO{sup {minus}}){gt}D{sub 0}(ZnO) by 0.63 eV. This, together with the literature value of D{sub 0}(ZnO), gives a value for D{sub 0}(ZnO{sup {minus}}) of 2.24 eV. Since the extra electron in ZnO{sup {minus}} is expected to occupy an antibonding orbital, the combination of D{sub 0}(ZnO{sup {minus}}){gt}D{sub 0}(ZnO), {omega}{sub e}(ZnO{sup {minus}}){lt}{omega}{sub e}(ZnO), and r{sub e}(ZnO{sup {minus}}){gt}r{sub e}(ZnO) was initially puzzling. An explanation was provided by the calculations of Bauschlicher and Partridge, which are presented in the accompanying paper. Their work showed that our experimental findings can be understood in terms of the athinsp{sup 3}{Pi} state of ZnO dissociating to its ground-state atoms, while the Xthinsp{sup 1}{Sigma}{sup +} state of ZnO formally dissociates to a higher energy atomic asymptote. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 663695
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 19 Vol. 109; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AFFINITY
ANIONS
BOND LENGTHS
ELECTRONEGATIVITY
FRANCK-CONDON PRINCIPLE
MOLECULAR IONS
MOLECULAR STRUCTURE
PHOTOELECTRON SPECTROSCOPY
VIBRATIONAL STATES
ZINC COMPOUNDS
ZINC OXIDES