The Even-Odd Rule on Single Covalent-Bonded Structural Formulas as a Modification of Classical Structural Formulas of Multiple-Bonded Ions and Molecules
Geoffroy Auvert
CEA-Leti, Grenoble, France.
DOI: 10.4236/ojpc.2014.44020   PDF    HTML   XML   3,437 Downloads   4,320 Views   Citations


In organic chemistry, as defined by Abegg, Kossel, Lewis and Langmuir, compounds are normally represented using structural formulas called Lewis structures. In these structures, the octet rule is used to define the number of covalent bonds that each atom forms with its neighbors and multiple bonds are frequent. Lewis’ octet rule has unfortunately shown limitations very early when applied to non-organic compounds: most of them remain incompatible with the “rule of eight” and location of charges is uncertain. In an attempt to unify structural formulas of octet and non-octet molecules or single-charge ions, an even-odd rule was recently proposed, together with a procedure to locate charge precisely. This even-odd rule has introduced a charge-dependent effective-valence number calculated for each atom. With this number and the number of covalent bonds of each element, two even numbers are calculated. These numbers are both used to understand and draw structuralformulas of single-covalent-bonded compounds. In the present paper, a procedure is proposed to adjust structural formulas of compounds that are commonly represented with multiple bonds. In order to keep them compatible with the even-odd rule, they will be represented using only single covalent bonds. The procedure will then describe the consequences of bond simplification on charges locations. The newly obtained representations are compared to their conventional structural formulas, i.e. single-bond representation vs. multiple-bond structures. Throughout the comparison process, charges are precisely located and assigned to specific atoms. After discussion of particular cases of compounds, the paper finally concludes that a rule limiting representations of multiplecovalent bonds to single covalent bonds, seems to be suitable for numerous known compounds.

Share and Cite:

Auvert, G. (2014) The Even-Odd Rule on Single Covalent-Bonded Structural Formulas as a Modification of Classical Structural Formulas of Multiple-Bonded Ions and Molecules. Open Journal of Physical Chemistry, 4, 173-184. doi: 10.4236/ojpc.2014.44020.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Couper, A.S. (1858) Sur une nouvelle théorie chimique. Annales de chimie et de physique, 53, 488-489.
[2] Loschmidt, J. (1861) Chemische Studien. Carl Gerold’s Sohn, Vienna.
[3] Abegg, R. (1904) Die Valenz und das periodische System. Zeitschrift für anorganische Chemie, 39, 330-380.
[4] Lewis, G.N. (1916) The Atom and the Molecule. Journal of the American Chemical Society, 38, 762-785.
[5] Langmuir, I. (1919) The Arrangement of Electrons in Atoms and Molecules. Journal of the American Chemical Society, 41, 868-934.
[6] Musher, J.I. (1969) The Chemistry of Hypervalent Molecules. Angewandte Chemie Internationale Edition, 8, 54-68.
[7] Gillespie, R.J. and Popelier, P.L.A. (2001) Chemical Bonding and Molecular Geometry. Oxford University Press, Oxford.
[8] Auvert, G. (2014) Improvement of the Lewis-Abegg-Octet Rule Using an “Even-Odd” Rule in Chemical Structural Formulas: Application to Hypo and Hypervalences of Stable Uncharged Gaseous Single-Bonded Molecules with Main Group Elements. Open Journal of Physical Chemistry, 4, 60-66.
[9] Auvert, G. (2014) Chemical Structural Formulas of Single-Bonded Ions Using the “Even-Odd” Rule Encompassing Lewis’s Octet Rule: Application to Position of Single-Charge and Electron-Pairs in Hypo- and Hyper-Valent Ions with Main Group Elements. Open Journal of Physical Chemistry, 4, 67-72.
[13] Greenwood, N.N. and Earnshaw, A. (1998) Chemistry of the Elements. 2nd Edition, Butterworth-Heinemann.
[14] Kekulé, A. (1865) Sur la constitution des substances aromatiques. Bulletin de la Société Chimique de Paris, 3-2, 98-110.
[15] Wurtz, C.A. (1872) Sur un aldéhyde-alcool. Compte Rendu de l’Académie des sciences, 74, 1361.
[16] Dowd, P. (1972) Trimethylenemethane. Accounts of Chemical Research, 5-7, 242-248.
[17] Tschitschibabin, A.E. (1907) über einige phenylierte Derivate des p, p-Ditolyls. Berichte der Deutschen Chemischen Gesellschaft, 40-2, 1810-1819.
[18] Pauling, L. (1946) Resonance. Oregon State University Libraries Special Collections.
[19] Pauling, L. (1960) The Concept of Resonance. The Nature of the Chemical Bond—An Introduction to Modern Structural Chemistry. 3rd Edition, Cornell University Press, Ithaca, 10-13.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.