ORGANIC-REACTIONS IN THE SOLID-STATE - ACCIDENT AND DESIGN

The factors that govern the nature and rate of thermally-stimulated and photochemical reactions in organic molecular crystals are reviewed. So far as thermal reactions are concerned, reference is made to the general kinetic patterns that prevail, to unusual dehydration and gas-solid reactions, and to certain single-crystal ⇆ single-crystal phase-transitions involving changes in the conformation of molecular cations. The particular advantages of using solvates and intercalates are also discussed. Radiation-induced reactions are reviewed within the framework of topochemistry and reference is made to temperature-independent polymerizations at cryogenic extremes, to (2+2) photopolymerizations at room temperature, to the reactions of derivatives of cinnamic acids, of poly-ynes (including diacetylenes), and of naphthaquinones. Recent progress in crystal engineering, assessing the role of structural imperfections, site-selective photochemistry, understanding the occurrence of stress-induced reactions, as well as in computing the structure of reactive crystals and the fine structure of imperfections, are also reviewed. Future prospects, especially those relating to the control of solid-state reactivity and the design of certain desired materials, are outlined. © 1979, Walter de Gruyter. All rights reserved.