7. Cyclopropyl Homoconjugation, Homoaromaticity and Homoantiaromaticity—Theoretical Aspects and Analysis

  1. Zvi Rappoport Professor
  1. Dieter Cremer1,
  2. Ronald F. Childs2 and
  3. Elfi Kraka1

Published Online: 6 JUL 2004

DOI: 10.1002/0470023481.ch7

Cyclopropyl Group, Volume 2

Cyclopropyl Group, Volume 2

How to Cite

Cremer, D., Childs, R. F. and Kraka, E. (2004) Cyclopropyl Homoconjugation, Homoaromaticity and Homoantiaromaticity—Theoretical Aspects and Analysis, in Cyclopropyl Group, Volume 2 (ed Z. Rappoport), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/0470023481.ch7

Editor Information

  1. The Hebrew University, Jerusalem, Israel

Author Information

  1. 1

    Department of Theoretical Chemistry, University of Göteborg, S-41296 Göteborg, Kemigården 3, Sweden

  2. 2

    Department of Chemistry, McMaster University, Hamilton, Ontario, Canada, L8S 4M1

Publication History

  1. Published Online: 6 JUL 2004
  2. Published Print: 15 DEC 1995

Book Series:

  1. PATAI'S Chemistry of Functional Groups

Book Series Editors:

  1. Saul Patai and
  2. Zvi Rappoport

ISBN Information

Print ISBN: 9780471940746

Online ISBN: 9780470023488

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Summary

This chapter contains sections titled:

  • Introduction

    • Models in Chemistry

    • Organization of the Chapter

  • Definition of Homoconjugation and Homoaromaticity—Basic Considerations

    • From Conjugation to Cyclopropyl Homoconjugation

      • Conjugation

      • Homoconjugation

    • From a Topological to a Chemical Definition of Homoconjugation

      • The Concept of Electron or Bond Delocalization

      • A Definition of Homoconjugation Based on the Concept of Bond (Electron) Delocalization

      • The Choice of Appropriate Reference Compounds

    • Homoaromaticity and Homoantiaromaticity

    • Homoconjugation and the Topology of the Potential Energy Surface: From Homoaromaticity to Frozen Transition States

  • Theoretical Aspects of Defining, Detecting and Describing Homoconjugation and Homoaromaticity

    • Winstein's Definition of Homoaromaticity

    • Description of Homoconjugative Interactions in Terms of Orbital Overlap

      • The Homotropenylium Cation as a Test Case

    • The PMO Description of Homoaromaticity

    • Description of a Homoconjugative Bond by Bond Orders and Other Interaction Indices

    • The Electron Density Based Definition of a Homoconjugative Bond

    • Description of Homoaromaticity in Terms of the Properties of the Electron Density Distribution

    • Energy-based Definitions of Homoaromaticity

      • Direct Calculation of Homoaromatic Stabilization Energies

      • Homoaromatic Stabilization Energies from Calculations with a Model Hamiltonian

      • Evaluation of Homoaromatic Stabilization Energies by Using Isodesmic Reactions

      • Evaluation of Homoaromatic Stabilization Energies by Using Homodesmotic Reactions

      • Homoconjugative Resonance Energies from Force Field Calculations

  • Ab initio Examinations of Homoconjugation

    • Basic Requirements

    • Investigation of the Homotropenylium Cation

      • Ab Initio Calculations of Geometry and Energy

      • Determination of the Equilibrium Geometry by the ab initio/Chemical Shift/NMR Method

    • Toward a General Definition of Homoaromaticity

      • Bond Homo(anti)aromaticity Caused by Cyclopropyl Homoconjugation

      • No-bond Homoaromaticity

      • General Remarks

  • Conclusions and Outlook

  • Acknowledgements

  • References