Presented are representative examples of the spectra and the analyses for a linear molecule (HC1), a symmetric top molecule (NH3), and an asymmetric top (H2O). Any combination of these projects could be incorporated in a physical chemistry or molecular spectroscopy laboratory. (RH)

Provides answers to these two questions: (1) What can be said about molecular structure? and (2) What are the foundations of theoretical chemistry? Indicates that students can be encouraged to think critically about primitive concepts of their subject (such as bonds and molecules) rather than passively accept them as truth. (JN)

Describes four principles essential to understanding the properties of biological molecules. Also uses classroom examples to aid in a discussion of instructional strategies for teaching these principles. (ZWH)

Explores the extent to which, in polycyclic hydrocarbons, the total pi electron population tends to form small (4n plus 2) groups and avoid the formation of 4n groups. Also discusses the relation of this trend to resonance energy stabilizations. (JN)

Describes steps (using monochiral and multichiral molecules) to enable students to arrive with relative ease at correct stereochemical relationships. The approach assumes familiarity with Fischer projection formulas and assignment of R and S absolute configurations. (JN)

Discussed and described are several types of chemical bonds: (1) ionic bonds; (2) covalent bonds; (3) hydrogen bonds; (4) bonds in the solid state; and (5) variation in bond strengths. (RH)

Shows how the structure-energy principle can be presented in organic chemistry (without having to resort to quantum mechanics) by use of Benson's Additive Rules. Examples of the application to several major classes of organic compounds are given.

Explores the question "Why are so many stationary states allowed by traditional quantum mechanics not realized in nature?" through discussion of classical observables and superselection rules. Three examples are given that can be used in introductory courses (including the fermion/boson property and the mass of a "nonrelativistic" particle). (JN)

Presents procedures for obtaining and examples of delta plots (a way of illustrating electron density changes associated with electronic excitation). These plots are pedagogically useful for visualizing simple and complex transitions and provide a way of "seeing" the origin of highest occupied molecular orbital (HOMO)-dictated carbonyl…

Describes software which demonstrates some features of three-dimensional protein structure on microcomputers. The program only displays the polypeptide backbone drawn through the alpha-carbon positions and is therefore much less sophisticated, but it has been used successfully during lectures on protein structure and as an adjunct to slides and…

Advantages of representing ternary and quaternary composition diagrams by means of rectangular coordinates were pointed out in a previous paper (EJ 288 693). A further advantage of that approach is that analytic geometry, based on rectangular coordinates, is directly applicable as demonstrated by the examples presented. (JN)

Discusses model studies aimed at elucidating various ways in which molecular oxygen interacts with metalloproteins. The focus is on the chemistry of iron(II) porphyrins and their adducts with nitrogenous bases, carbon monoxide, and dioxygen, which are most relevant to the functional proteries of the heme proteins, hemoglobin, and myoglobin. (JN)

Several chemical concepts can be visualized by using deformation density maps. They often present convincing experimental confirmation and they should be incorporated into the chemistry curriculum dealing with bonding and molecular structure. Examples of the maps and quantitative information derived from research studies are presented. (JN)

Compares linear-nonlinear and planar-nonplanar geometry through the valence-shell electron pairs repulsion (V.S.E.P.R.), Mulliken-Walsh, and electrostatic force theories. Indicates that although the V.S.E.P.R. theory has more advantages for elementary courses, an explanation of the best features of the different theories offers students a better…

Assigning "R" or "S" descriptors to chiral centers by inspection of a stereoformula often results in mistakes, especially when three-dimensional representations (with solid and dashed bonds for substituents pointing to front or rear) are used. Therefore, a method is presented that can be applied to all three-dimensional…