No Access Submitted: 18 May 1998 Accepted: 14 August 1998 Published Online: 16 November 1998
J. Chem. Phys. 109, 8426 (1998); https://doi.org/10.1063/1.477505
more...View Affiliations
  • Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218
View Contributors
  • C. A. Fancher
  • H. L. de Clercq
  • O. C. Thomas
  • D. W. Robinson
  • K. H. Bowen
We have recorded, assigned, and analyzed the photoelectron spectrum of ZnO. The adiabatic electron affinity (E.A.a) of ZnO and the vibrational frequencies of both ZnO and ZnO were determined directly from the spectrum, with a Franck–Condon analysis of its vibrational profile providing additional refinements to these parameters along with structural information. As a result, we found that E.A.a(ZnO)=2.088±0.010 eV, ωe(ZnO)=805±40 cm−1, ωe(ZnO)=625±40 cm−1, and that re(ZnO)>re(ZnO) by 0.07 Å. Since our measured value of E.A.a(ZnO) is 0.63 eV larger than the literature value of E.A.(O), it was also evident, through a thermochemical cycle, that D0(ZnO)>D0(ZnO) by 0.63 eV. This, together with the literature value of D0(ZnO), gives a value for D0(ZnO) of 2.24 eV. Since the extra electron in ZnO is expected to occupy an antibonding orbital, the combination of D0(ZnO)>D0(ZnO), ωe(ZnO)<ωe(ZnO), and re(ZnO)>re(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 a 3Π state of ZnO dissociating to its ground-state atoms, while the X 1Σ+ state of ZnO formally dissociates to a higher energy atomic asymptote.
  1. 1. W. Hirschwald, in Current Topics in Materials Science, Vol. 6, edited by E. Kaldis (North Holland, Amsterdam, 1980), pp. 109–194. Google Scholar
  2. 2. M. S. Chandrasekharaiah, in The Characterization of High-Temperature Vapors, edited by J. L. Margrave (Wiley, New York, 1967), pp. 495–500. Google Scholar
  3. 3. S. Monticone, R. Tufeu, and A. V. Kanaev, J. Phys. Chem. B 102, 2854 (1998). Google ScholarCrossref
  4. 4. L. Brewerand D. F. Mastick, J. Chem. Phys. 19, 834 (1951). Google ScholarScitation
  5. 5. L. Brewer, Chem. Rev. 52, 1 (1953). Google ScholarCrossref
  6. 6. W. J. Mooreand E. L. Williams, J. Phys. Chem. 63, 1516 (1959). Google ScholarCrossref
  7. 7. W. J. Mooreand E. L. Williams, Discuss. Faraday Soc. 28, 86 (1959). Google ScholarCrossref
  8. 8. E. A. Secco, Can. J. Chem. 38, 596 (1960). Google ScholarCrossref
  9. 9. T. C. M. Pillay, J. Electrochem. Soc. 109, 76C, Abstract 134 (1962). Google ScholarCrossref
  10. 10. W. Hirschwald, F. Stolze, and I. N. Stranski, Z. Phys. Chem., Neue Folge 42, S, 96 (1964). Google ScholarCrossref
  11. 11. D. F. Anthropand A. W. Searcy, J. Phys. Chem. 68, 2335 (1964). Google ScholarCrossref
  12. 12. B. G. Wicke, J. Chem. Phys. 78, 6036 (1983). Google ScholarScitation
  13. 13. O. Gropen, U. Wahlgren, and L. Pettersson, Chem. Phys. 66, 459 (1982). Google ScholarCrossref
  14. 14. C. W. Bauschlicherand S. R. Langhoff, Chem. Phys. Lett. 126, 163 (1986). Google ScholarCrossref
  15. 15. M. Dolg, U. Wedig, H. Stoll, and H. Preuss, J. Chem. Phys. 86, 2123 (1987). Google ScholarScitation
  16. 16. E. G. Bakalbassis, M. A.-D. Stiakaki, A. C. Tsipis, C. A. Tsipis, Chem. Phys. 205, 389 (1996). Google ScholarCrossref
  17. 17. C. W. Bauschlicherand H. Partridge, J. Chem. Phys.109, 8430 (1998), following paper. Google ScholarScitation
  18. 18. D. E. Clemmer, N. F. Dalleska, and P. B. Armentrout, J. Chem. Phys. 95, 7263 (1991). Google ScholarScitation
  19. 19. L. R. Watson, T. L. Thiem, R. A. Dressler, R. H. Salter, and E. Murad, J. Phys. Chem. 97, 5577 (1993). Google ScholarCrossref
  20. 20. E. S. Prochaskaand L. Andrews, J. Chem. Phys. 72, 6782 (1980). Google ScholarScitation
  21. 21. J. V. Coe, J. T. Snodgrass, C. B. Freidhoff, K. M. McHugh, and K. H. Bowen, J. Chem. Phys. 84, 618 (1986). Google ScholarScitation
  22. 22. H. W. Sarkas, J. H. Hendricks, S. T. Arnold, V. L. Slager, and K. H. Bowen, J. Chem. Phys. 100, 3358 (1994). Google ScholarScitation
  23. 23. P. M. Dehmerand W. A. Chupka, J. Chem. Phys. 62, 4525 (1975). Google ScholarScitation
  24. 24. K. M. Ervin and W. C. Lineberger, in Advances in Gas Phase Ion Chemistry, Vol. I, edited by N. G. Adams and L. M. Babcock (JAI, Greenwich, 1992). Google Scholar
  25. 25. PESCAL Fortran program, written by K. M. Ervin and W. C. Lineberger. Google Scholar
  26. 26. “Because the reaction of Zn+(2S)+NO2(2A)→ZnO(1Σ+)+NO+(1Σ+) is spin-allowed, formation of the ZnO ground state at the threshold for reaction is expected” (P. B. Armentrout, private communication). Google Scholar
  1. © 1998 American Institute of Physics.