There are significant contradictions in undergraduate organic chemistry textbooks as to the mechanism of nucleophilic substitution reactions at saturated secondary carbons. Some texts say that only the S[subscript N]2 mechanism operates, others say that solvolysis reactions go entirely by the S[subscript N]1 mechanism, while most texts say that…

Previous articles have dealt with the special problems arising when attempting to reduce reducible representations in continuous point groups. Current work, involving the programing of "projection operators" in connection with numerical computations, also shows the continuous groups to present special problems. These problems are…

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)

The generator set of a group is the subset of the set of elements of the group. The nature and use of generator sets is discussed, focusing on generator sets for the noncubic symmetry point groups containing one, two, and three symmetry elements. (JN)

Reports on a low-cost and unique molecular model set capable of generating a large number of structures for teaching and learning general chemistry. An important component of the kit is an 11-hole ball that gives tetrahedral, octahedral, trigonal, trigonal bipyramidal, and square planar symmetries. (WRM)

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)

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 symmetry elements of molecules, symmetry operations, and point groups. Gives ten examples of assigning a point group to a molecule. (MLH)

Discusses topics about the structure of the solid state that are suitable for introductory chemistry; included are unit cells and simple molecular structures. (MLH)

Discusses the chirality of the disulfide bond and its significance in the structure and activity of biomolecules. (SL)

Reviews problems encountered in unimolecular reaction theory. (SL)

Focuses on a recent approach to chirality that seeks to call attention to the fact that current usage of this term is often inconsistent with its proper relationship to molecular structure. (TW)

Provides definitions for 31 commonly used polymer science terms. (JM)

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…