CHEMISTRY EDUCATION: RESEARCH AND PRACTICE IN EUROPE 2002, Vol. 3, No. 2, pp. 119-127	Theme Issue 2 on Structural Concepts CONTRIBUTION FROM SCIENCE

Padeleimon KARAFILOGLOU
Aristotle University of Thessaloniki, Faculty of Chemistry

UNDERSTANDING DELOCALIZATION AND HYPERCONJUGATION IN TERMS OF (COVALENT AND IONIC) RESONANCE STRUCTURES

ABSTRACT: Electron transfer (from bonding to anti-bonding orbitals) effects, as delocalization and hyperconjugation, are translated into a language referring to resonance structures of covalent and ionic components of bonds. These effects are presented as examples destined to familiarize students with the translation of molecular orbital wave functions into the chemically meaningful language of resonance structures. 'Structural multiplication tables' are introduced as a pedagogical tool, allowing one to generate resonance structures in a pictorial manner. It is shown that the transfer of one electron from a bonding orbital, (donor), to an anti-bonding one, (acceptor), creates an odd (an unpaired) electron in region (i,j) and another odd electron in region (k,l); the coupling of these two odd electrons provides the necessary covalent component(s) of the new bond(s) between the donor and the acceptor. [Chem. Educ. Res. Pract. Eur., 2002, 3, 119-127]

KEY WORDS: delocalization; hyperconjugation; resonance structures; electron transfer; natural bond orbitals - Slater determinants

CORRESPONDENCE: Padeleimon KARAFILOGLOU , POB 135, Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; e-mail: karafilo@ccf.auth.gr

[About CERP] [Current Issue] [Past Issues] [Note on Safety]
[Reviewers of CERP] [New Call for Papers] [Guidelines for Submissions]
[Submission Form (PDF)][Help] [Home]