Shows how to make close-packed models from balloons and table tennis balls to illustrate structural features of clusters and organometallic cluster-compounds (which are of great interest in the study of chemical reactions). These models provide a very inexpensive and tactile illustration of the organization of matter for concrete operational…

Provides instructions for making, inexpensively from envelopes, two polyhedra that illustrate chemical geometries. The individual steps involved, supported by detailed diagrams, are included. (JN)

Discusses a successfully implemented laboratory experiment that compares the strengths and weaknesses of mechanical and computer models. The computer models used are available from the Quantum Chemistry Program Exchange (QCPE) at a modest price. (JN)

Describes the nature and capabilities of methods used to characterize protein and peptide structure, indicating that they have undergone changes which have improved the speed, reliability, and applicability of the process. Also indicates that high-performance liquid chromatography and gel electrophoresis have made purifying proteins and peptides a…

Describes the chemical structure of paper, including subatomic particles, atoms and molecules, and the forces that bond atoms into molecules, molecules into chains, chains into sheets, and sheets into layers. Acid is defined, and the deleterious role of acid in breaking the forces that bond atoms into molecules is detailed. (EJS)

Cartilage is a fundamental biological material that helps to shape the body and then helps to support it. Its fundamental properties of strength and resilience are explained in terms of the tissue's molecular structure. (JN)

Demonstrates the novelty and variety of the structue relationships in a class of cage molecules similar to cubane; syntheses for these substances are shown. (MLH)

Structural formulas give professional chemists information about physical and chemical properties of corresponding compounds. In chemistry education at secondary schools, structural formulas are introduced in the context of chemical bonding. Structural formulas are not introduced as representations of the properties of chemical compounds. This…

Recent investigations show that the ipso position competes effectively with unsubstituted positions in many aromatic substitution reactions, regardless of charge type of reaction. Selected examples available for nucleophilic, electrophilic, and free radical reactions are reviewed to suggest the range of ipso reactions. (JN)

Discusses a simple, effective way of teaching S and R configurations for chiral molecules containing asymmetric centers. The method involves converting wedge/spatial representations to Fischer projections and prioritizing groups according to the Cahn-Ingold-Prelog sequence rules. Two examples illustrating the method are included. (JN)

Discusses the relationship between molecular structure, intermolecular forces, and tensile strengths of a polymer and suggests that this is a logical way to introduce polymers into a general chemistry course. (Author/JN)

In representing conformational equilibria of compounds having only one chiral center, erroneous formulas showing different antipodes on the two sides of the equilibrium are rare. In contrast, with compounds having two or more chiral centers especially with saturated heterocycles, this erroneous representation occurs frequently in the chemical…

Describes a method for specifying R/S (clockwise/counterclockwise) configuration about a chiral center which does not require the use of a three-dimensional physical model, the mental visualization of the molecule, or the memorization of a recently reported arbitrary number system. (Author/JN)

Presents a procedure for evaluating the required integrals for undergraduate students attempting to understand the consequences of perturbation theory. (CS)