Hückel Theory I and II©
James M. LoBue Department of Chemistry Georgia Southern University P. O. Box 8064 Statesboro, GA 30460 United States mail to: jlobue@gasou.edu
Abstract
The focus of Huckel theory in the chemistry curriculum is usually the determination of the orbitals and energy levels of a conjugated system. Students are then able to learn the basic analysis of a simple orbital problem. Using the linear algebra functions available in Mathcad, it is now possible to describe, almost completely, the process that results in orbitals and levels. All that is lacking is an exploration of the algorithm for matrix diagonalization. The Huckel I and II Mathcad documents provide a review of, or perhaps an introduction to the Heisenberg formulation of quantum mechanics. Therefore, these pages are geared toward the advanced undergraduate, the beginning graduate student, or even the talented junior chemistry major. Described in Huckel I is an introduction to the method of generating Huckel Theory results along with an introduction to applications like HOMO-LUMO transition energy and the prediction of nucleophilic and electrophilic substitution. Huckel II treats more sophisticated topics like the generation of partial charges, bond orders, and the determination of aromatic character. Since these topics have ab-initio analogs, Huckel I and II provide a "hands-on" introduction to important aspects of computational chemistry as well. The development found in Huckel I and II could easily be extended to molecules with heteroatoms and it is expected that other workers will find further extensions.
Commentary
Editor's Commentary
Keywords
Audiences: Upper-Division Undergraduate Pedagogies: Computer-Based Learning Domains: Physical Chemistry Topics: Mathematics / Symbolic Mathematics, MO Theory, Quantum Chemistry, Theoretical Chemistry
Documents
File Name Description Software Type Software Version HucI_8.mcd Mathcad 8 Computational Document. Mathcad 8 HucI_2001.mcd Mathcad 2001 Computational Document. Mathcad 2001 HucII_8.mcd Mathcad 8 Computational Document. Mathcad 8 HucII_2001.mcd Mathcad 2001 Computational Document. Mathcad 2001 HucI_2001.PDF Read-Only Document HucII_2001.PDF Read-Only Document JCE Subscribers only: name and password or institutional IP number access required.
Citations
LoBue, J. M. J. Chem. Educ. 2002, 79, 1378.
Comments to: James LoBue at jlobue@gasou.edu
©Copyright 2002 Journal of Chemical Education