σ-Homoconjugation in cyclically preoriented N4-(radical) cations - N···N bond lengths > 2 Å

Angewandte Chemie - International Edition

Volumn 39, Issue 8, 2000, Pages 1455-1458

  Exner, Kai ^a   Großmann, Birgit ^a   Gescheidt, Georg ^b   Heinze, Jürgen ^a   Keller, Manfred ^a   Bally, Thomas ^c   Bednarek, Pavel ^c   Prinzbach, Horst ^a  

^a UNIVERSITY OF FREIBURG   (Germany)

^b UNIVERSITY OF BASEL   (Switzerland)

^c UNIVERSITY OF FRIBOURG   (Switzerland)

Author keywords

Cations; EPR spectroscopy; Homoconjugation; Polycycles; Radicals

Indexed keywords

CATION;

ARTICLE; CHEMICAL BINDING; CONJUGATION; ELECTRON TRANSPORT; MOLECULAR INTERACTION; SYNTHESIS;

EID: 0040784287     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(20000417)39:8<1455::AID-ANIE1455>3.0.CO;2-W     Document Type: Article

References (30)

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2. For reviews on homoconjugation (homoaromaticity) in carbanions, see: L. A. Paquette, Angew. Chem. 1978, 190, 114-125; Angew. Chem. Int. Ed. Engl. 1978, 17, 106-117; G. R. Stevenson in Molecular Structure and Energetics (Eds.: J. F. Liebman, A. Greenberg), VCH, New York, 1986, p. 57; Aromaticity and Antiaromaticity (Eds.: V. I. Minkin, M. N. Glukhovtsev, B. Y. Simkin), Wiley, New York, 1994, p. 243; P. von R. Schleyer, H. Jiao, Pure Appl. Chem. 1996, 68, 209- 218. For examples of "aromaticity" in inorganic rings, see: P. von R. Schleyer, H. Jiao, N. J. R. van Eikema Hommes, V. G. Malkin, O. L. Malkina, J. Am. Chem. Soc. 1997, 119, 12669-12670.
3. For reviews on homoconjugation (homoaromaticity) in carbanions, see: L. A. Paquette, Angew. Chem. 1978, 190, 114-125; Angew. Chem. Int. Ed. Engl. 1978, 17, 106-117; G. R. Stevenson in Molecular Structure and Energetics (Eds.: J. F. Liebman, A. Greenberg), VCH, New York, 1986, p. 57; Aromaticity and Antiaromaticity (Eds.: V. I. Minkin, M. N. Glukhovtsev, B. Y. Simkin), Wiley, New York, 1994, p. 243; P. von R. Schleyer, H. Jiao, Pure Appl. Chem. 1996, 68, 209- 218. For examples of "aromaticity" in inorganic rings, see: P. von R. Schleyer, H. Jiao, N. J. R. van Eikema Hommes, V. G. Malkin, O. L. Malkina, J. Am. Chem. Soc. 1997, 119, 12669-12670.
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5. For reviews on homoconjugation (homoaromaticity) in carbanions, see: L. A. Paquette, Angew. Chem. 1978, 190, 114-125; Angew. Chem. Int. Ed. Engl. 1978, 17, 106-117; G. R. Stevenson in Molecular Structure and Energetics (Eds.: J. F. Liebman, A. Greenberg), VCH, New York, 1986, p. 57; Aromaticity and Antiaromaticity (Eds.: V. I. Minkin, M. N. Glukhovtsev, B. Y. Simkin), Wiley, New York, 1994, p. 243; P. von R. Schleyer, H. Jiao, Pure Appl. Chem. 1996, 68, 209-218. For examples of "aromaticity" in inorganic rings, see: P. von R. Schleyer, H. Jiao, N. J. R. van Eikema Hommes, V. G. Malkin, O. L. Malkina, J. Am. Chem. Soc. 1997, 119, 12669-12670.
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14. Preliminary communication, see: K. Exner, D. Hunkler, G. Gescheidt, H. Prinzbach, Angew. Chem. 1998, 110, 2013-2016; Angew. Chem. Int. Ed. 1998, 37, 1910-1913.
15. K. Exner, Dissertation, University of Freiburg (Germany), 1998.
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18. K. Exner, G. Fischer, N. Bahr, E. Beckmann, M. Lugan, F. Yang, G. Rihs, M. Keller, D. Hunkler, L. Knothe, H. Prinzbach, Eur. J. Org. Chem. 2000, 763-785, and references therein.
19. 12.16]heptadecane.
20. 1), Crystallographic data (excluding structure factors) for the structure reported in this paper have heen deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-137669. Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: (+44) 1223-336-033; e-mail: deposit@ccdc.cam.ac.uk).
21. For geometry optimization:Gaussian 94, Revision E.2. Gaussian Inc., Pittsburgh, PA, 1995. For TD DFT-calculations:Gaussian 98, Revision A.6. Gaussian Inc., Pittsburgh, PA, 1998.
22. For geometry optimization:Gaussian 94, Revision E.2. Gaussian Inc., Pittsburgh, PA, 1995. For TD DFT-calculations:Gaussian 98, Revision A.6. Gaussian Inc., Pittsburgh, PA, 1998.
23. R. F. W. Bader, Atoms in Molecules - A Quantum Theory, Vol. 22, The International Series on Monographs in Chemistry, Calderon Press, Oxford, 1995. For the analysis EXTREME of the AIMPAC-program packet was used.
24. Compare the approximately 2 Å bond length in silaethene - amine adducts: N. Wiberg, K.-S. Joo, K. Polborn, Chem. Ber. 1993, 126, 67-69.
25. For the oxidation of hydrazines in related structures, see: S. Nelsen in Studies of Organic Molecules, Vol. 3 (Eds.: J. F. Liebmann, A. Greenberg), VCH, Weinheim, 1986, pp. 1-56, and references therein; S. Hünig, F. Prokschy, Chem. Ber. 1984, 117, 2099-2111.
26. For the oxidation of hydrazines in related structures, see: S. Nelsen in Studies of Organic Molecules, Vol. 3 (Eds.: J. F. Liebmann, A. Greenberg), VCH, Weinheim, 1986, pp. 1-56, and references therein; S. Hünig, F. Prokschy, Chem. Ber. 1984, 117, 2099-2111.
27. The SOMO and SOMO-1 of the radical cation 5 corespond to the HOMO and HOMO-1 of neutral 2. The HOMO of 2 is described as the antibonding combination of the four nonhonding electron pairs at the nitrogen atoms.
28. An additional wave is observed at about 0.01 V in the backsweep, which disappears at faster scan rates. The nature of the corresponding novel 4N/7e radical cation will be reported separately. K. Exner, B. Großmann, G. Gescheidt, J. Heinze, M. Keller, T. Bally, P. Bednarek, H. Prinzbach, unpublished results.
29. T. Bally, B. Albrecht, S. Matzinger, M. G. Sastry; the program can be obtained from T. Bally (Thomas.Bally@unifr.ch).
30. R. E. Stratmenn, G. E. Scuseria, M. J. Frisch, J. Chem. Phys. 1998, 109, 8218-8224.