GROUPS OF ORGANIC-MOLECULES THAT OPERATE COLLECTIVELY

A "chemical system" is defined as an assemblage of molecules that collectively does something interesting or useful. The key word here is "collectively", a word that implies an interdependency and a group behavior that can be quite different from that of individual molecules. Batteries, computer chips, concrete, mayonnaise, shampoo, paint, liquid crystal displays, composites, and viruses are all examples of commonly encountered systems. A host-guest or "supramolecular" complex, on the other hand, would not be considered a system (as defined here), because only two species are involved. A chemical system is multimolecular, a collection of molecules interlocked in a tangle of dependencies. The review delves into a variety of chemical systems investigated by the author, including micelles, water pools, films, vesicles, and polymers. All of them can be categorized as "self-assembling" or "self-organizing" in the sense that defined structures arise spontaneously owing to noncovalent forces among the component molecules. Such chemical systems are useful for many purposes, including decontamination of environmentally dangerous substances, drug delivery, and separation of organic compounds.