Abstract
The equilibrium conformations of trans- and cis-stilbene and the rotational barrier between the two isomers were calculated using the CNDO/2 method. The results for the equilibrium angles and distances are in good agreement with experimental data. However, according to the calculations the phenyl rings would have a nearly free rotation which is only limited by steric hindrance. This result obviously deviates from the current view. The results are discussed in relation to previous theoretical and experimental evidence.
Zusammenfassung
Die Gleichgewichtskonformation von trans- und cis-Stilben und die Rotationsbarriere zwischen zwei Isomeren wurde nach der CNDO/2-Methode berechnet. Die Ergebnisse in bezug auf die Geometrie stimmen mit experimentellen Daten gut überein, die Rotationsbarriere für die Drehung der Phenylringe dagegen ist praktisch Null.
Résumé
La méthode CNDO/2 a été employée pour calculer les conformations d'équilibre du trans- et du cis-stilbène ainsi que la barrière de rotation entre ces deux isomères. Angles d'équilibre et distances calculés sont en bon accord avec les données expérimentales. Cependant les calculs indiquent que les cycles phényles devraient posséder une rotation libre soumise seulement à l'empêchement stérique. Ce résultat s'écarte de l'opinion courante. Les résultats sont discutés en relation avec les données théoriques et expérimentales antérieures.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Pople, J. A., Santry, D. P., Segal, G. A.: J. chem. Physics 43, 129 (1965).
—, Segal, G. A.: J. chem. Physics 43, 136 (1965).
— —: J. chem. Physics 44, 3289 (1966).
Santry, D. P., Segal, G. A.: J. chem. Physics 47, 158 (1967).
—: J. Amer. chem. Soc. 90, 3309 (1968).
Robertson, J. M., Woodward, I.: Proc. Roy. Soc. (London) A162, 568 (1937).
Dewar, M. J. S.: The molecular orbital theory of organic chemistry. New York: McGraw-Hill Book Co. 1969.
Kistiakowsky, G. B., Smith, W. R.: J. Amer. chem. Soc. 56, 638 (1934).
Fischer, H., Kollmar, H.: Theoret. chim. Acta (Berl.) 13, 213 (1969).
Weiss, K., Warren, C, Wettermark, G.: To be published.
Tinland, B.: Theoret. chim. Acta (Berl.) 11, 452 (1968).
Dhar, J.: Indian J. Physics 7, 43 (1932).
Robertson, J. M.: Nature 191, 593 (1961).
Bastiansen, O.: Acta chem. scand. 3, 408 (1949).
—: Acta chem. scand. 4, 926 (1950).
—, Smedvik, L.: Acta chem. scand. 8, 1539 (1954).
Suzuki, H.: Electron absorption spectra and geometry of organic molecules. New York: Academic Press 1967.
Fremstad, D., Borgen, O.: Personal communication.
Fischer, G., Muszkat, K. A., Fischer, E.: J. chem. Soc. (London) (B) 1968, 1156.
Salem, L.: The molecular orbital theory of conjugated systems. New York: W. A. Benjamin, Inc. 1966.
Liberles, A.: Introduction to molecular orbital theory. New York: Holt, Rinehart and Winston, Inc. 1966.
Wheland, G. A.: Resonance in organic chemistry. New York: John Wiley and Sons, Inc. 1955.
Adrian, F. J.: J. chem. Physics 28, 608 (1958).
Fink, W. H., Allen, L. C.: J. chem. Physics 46, 2261, 2276 (1967).
— —: J. chem. Physics 47, 895 (1967).
Allen, L. C.: Chem. Physics Letters 2, 597 (1968).
Wyatt, R. E., Parr, R. G.: J. chem. Physics 43, 217 (1965).
Lowe, J. P., Parr, R. G.: J. chem. Physics 43, 2565 (1965).
Weiss, S., Leroi, G. F.: J. chem. Physics 48, 962 (1968).
Suzuki, H.: Bull. chem. Soc. Japan 33, 381 (1960).
Kanda, Y.: Mem. Fac. Sci. Kyushu. Univ. Ser. C1, 189 (1950).
Jaffé, H. H., Orchin, M.: Theory and applications of ultraviolet spectroscopy. New York: John Wiley and Sons, Inc. 1965.
Author information
Authors and Affiliations
Additional information
This work was supported by grant No 2741-4 from The Swedish Natural Science Research Council and grant No 69-927/U 697 from The Swedish Board for Technical Development.
Rights and permissions
About this article
Cite this article
Ljunggren, S., Wettermark, G. A CNDO/2 calculation on stilbene. Theoret. Chim. Acta 19, 326–334 (1970). https://doi.org/10.1007/BF00527693
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00527693