Chemical Education Today
Book & Media Reviews
Lewis Acid/Base Reaction Chemistry by Mark R. Leach Meta-Synthesis.Com: Brighton, UK, 1999. 95 pp. Figures, tables, wall chart, and CD-ROM tutorials. ISBN 0953696006. $45 (paper), reviewed by John C. Cochran
Lewis Acid/Base Reaction Chemistry is the first in a series of short primers to be written by Professor Leach and to be published by Meta-Synthesis.Com. The series is called Patterns in Reaction Chemistry and the forthcoming volumes will cover reactions in the areas of redox chemistry, photochemistry, radical chemistry, and diradical chemistry. The approach to the material is based on a series of tutorials found on a CD-ROM. Students are encouraged to study the tutorials and are then referred to the reaction matrix in the text. A large wall chart displays the matrix and provides a look at the big picture. Lewis acid/base chemistry is shown to be the product of six types of frontier molecular orbital Lewis acids and four types of frontier molecular orbital Lewis bases. The Lewis acid types are (i) the proton Lewis acid, (ii) s-LUMO Lewis acids, (iii) onium ion Lewis acids, (iv) lobe-LUMO Lewis acids, (v) π-LUMO Lewis acids, and (vi) heavy metal Lewis acids. The Lewis base types are (i) s-HOMO Lewis bases, (ii) complex anion Lewis bases, (iii) lobe-HOMO Lewis bases, and (iv) π -HOMO Lewis Bases. Each of these species is described with respect to its frontier molecular orbital topology, charge, Pearson hard/soft character, and chemistry. The cross products of these acids and bases result in 24 types of complexes. For example, when the benzyl cation, a π-LUMO Lewis acid, combines with the hydride ion, an s-HOMO Lewis base, the product, toluene, is considered a Lewis acid/base complex in which the π system has been partially reduced. In another example, the products of s-LUMO Lewis acids and s-HOMO Lewis bases, the metal hydrides, show trends of properties (basicity, in this case) in a congeneric series down the metal groups. Four addition types of complexes are considered. These are hydrogen bond complexes, anion bridge bond complexes, van der Waals attraction complexes, and molecular shape recognition complexes. Finally, ambidentate Lewis acid/base reactivity is considered. It is difficult to do justice to the amount of chemical information contained on the accompanying CD. The CD is divided into two sections: Tutorials and The Database. The tutorials include first a recap of the Lewis acid/base interaction matrix, described above, tutorials that define in detail reaction chemistry and electronic theory. These tutorials begin at a
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level for which very little background is necessary and progress to a rather sophisticated discussion of reactions and theory. The former tutorial summarizes all aspects of material reaction chemistry from chemical species to chemical reactions, and mechanisms to reaction types. A second part of this tutorial summarizes the intellectual realm. The topics include physical theory, analytical methodology, and the chemical literature. The electronic theory portion of this tutorial begins with Lewis octet theory and ends with frontier molecular orbital theory. The next tutorials apply the electronic theory to the five reaction chemistries that constitute the Patterns in Reaction Chemistry series. For instance, photochemistry includes a discussion of the electromagnetic radiation spectrum. These discussions lead to a label of the reaction chemistries as paradigms. The database on the CD is divided into two sections: Species and Reactions. Each section can be easily searched to obtain a specific compound or class of compounds and specific reaction or type of reaction. The Species section contains well over 2000 entries of both real chemical entities and generic chemical species. Each entry has a screen with structure and useful physical data; and data for most compounds include reactions of formation or reactions of utilization. A few 1H NMR, 13C NMR, IR, and mass spectra are also shown. One can search for a compound or generic structure using several sorting menus. This reagent database serves as a mini chemical handbook. The second part of the Database contains more than 1400 chemical reactions, which include starting reagents and products. Each reaction has a reaction data page that defines the reaction as a member of one of the 24 reaction types in the Lewis acid/base matrix. The data page also lists reaction temperatures and equilibrium constants and leads to an information page that gives a somewhat detailed account of the mechanism of the reaction. This section of the Database can also be searched for types of mechanisms and by collections of common reaction sequences. In summary, this monograph and its accompanying CD provide a unique approach to the organization of reaction chemistry. This approach sweeps aside the boundary between organic and inorganic reactions. The question remains of who would benefit by using this book and CD. I think that an undergraduate preparing for graduate school would find this pedagogy useful to integrate the vast amount of reaction chemistry accumulated during the undergraduate years. When the remaining books in the series become available, the set would make a good source for a capstone undergraduate course. John C. Cochran is in the Department of Chemistry, Colgate University, Hamilton, NY 13346;
[email protected].
Journal of Chemical Education • Vol. 78 No. 2 February 2001 • JChemEd.chem.wisc.edu
