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Theoretica chimica acta

, Volume 84, Issue 1–2, pp 125–133 | Cite as

Heavy-atom tunneling in cyclobutadiene:Ab initio calculation of the intensities ofa g Raman lines

  • P. Čársky
  • J. Michl
Article

Summary

GVB/[5s3p1d/3s1p] calculations were performed on the polarizability surface α(Я1, Я2, Я3) of cyclobutadiene. The threea g coordinates refer to automerization (Я1), symmetric CC stretch (Я2), and symmetric CCH bend (Я3). This surface was used together with the previously obtained variational vibrational wave functions for the calculation of Raman intensities. The calculation predicts comparable intensities for the two split components of the automerization Raman line in an isolated molecule and disagrees with observations on matrix-isolated cyclobutadiene. The disagreement is attributed to the asymmetry of the double-well potential imposed by the effect of the Ar matrix.

Key words

Raman intensities Tunneling Cyclobutadiene Ab initio calculations of polarizabilities Variational calculation of vibrational levels 

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References

  1. 1.
    Arnold BR, Radziszewski JG, Campion A, Perry SS, Michl J (1991) J Amer Chem Soc 113:692Google Scholar
  2. 2.
    Čársky P, Špirko V, Hess BA Jr, Schaad LJ (1990) J Chem Phys 92:6069Google Scholar
  3. 3.
    Čársky P, Downing JW, Michl J (1991) Int J Quantum Chem 40:415Google Scholar
  4. 4.
    Arnold BR, Michl J (1990) Spectroscopy of cyclobutadiene. In: Platz MS (ed) Kinetics and spectroscopy of carbenes and biradicals. Plenum, NY, p 1–35Google Scholar
  5. 5.
    Maier G (1988) Angew Chem Internat Ed Engl 27:309Google Scholar
  6. 6.
    Yamaguchi Y, Frisch MJ, Lee TJ, Schaefer HF III, Binkley JS (1986) Theor Chim Acta 69:337Google Scholar
  7. 7.
    For references see Jørgensen P, Simons J (eds) (1986) Geometrical derivatives of energy surfaces and molecular properties. Reidel, Dordrecht, The NetherlandsGoogle Scholar
  8. 8.
    Sadlej J (1988) Collect Czech Chem Commun 53:1995Google Scholar
  9. 9.
    Ozkabak AG, Thakur SN, Goodman L (1991) Int J Quantum Chem 39:411Google Scholar
  10. 10.
    Hougen JT, Bunker PR, Johns JWS (1970) J Mol Spectrosc 34:136Google Scholar
  11. 11.
    Leclercq JM, Sandorfy C (1983) J Raman Spectrosc 14:358Google Scholar
  12. 12.
    Kofranek M, Karpfen A, Lischka H (1992) Chem Phys Lett (in press)Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • P. Čársky
    • 1
  • J. Michl
    • 2
  1. 1.J. Heyrovský Institute of Physical Chemistry and ElectrochemistryCzechoslovak Academy of SciencesPrague 8Czechoslovakia
  2. 2.Department of Chemistry and BiochemistryUniversity of Colorado at BoulderBoulderUSA

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