ERIC Number: EJ1243330
Record Type: Journal
Publication Date: 2020-Feb
Pages: 9
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: N/A
Graphical Representation of Hückel Molecular Orbitals
Journal of Chemical Education, v97 n2 p448-456 Feb 2020
In this paper, we develop a general but very simple mathematical foundation for the predefined coefficient graphical method of Hückel molecular orbital theory (HMO). We first present the general solution for the recurrence relation of the coefficients of Hückel molecular orbitals (MOs). Subsequently, for all the three unbranched hydrocarbons, i.e., open-chain, cyclic Hückel and Möbius polyenes, different boundary conditions are explored for obtaining the MOs and their energy levels. The analytic continuation of the recurrence relation, in which one extends the domain from integral to real, allows us to analyze the symmetric properties of Hückel MOs in an elegant fashion without even knowing the actual expressions. In fact, we can use the symmetric properties to derive the Hückel MOs of the unbranched hydrocarbons and some branched hydrocarbons such as naphthalene. Consequently, this work also provides a pedagogical alternative to present the HMO model for students in an advanced physical chemistry course. Finally, the graphical approach could be a good mnemonic device for students' comprehension of the HMO theory.
Descriptors: Chemistry, Molecular Structure, Energy, Mathematics, Computation, Advanced Courses, Mnemonics
Division of Chemical Education, Inc. and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A