W0098

Reactive Crystals: Design and Discovery. Bruce M. Foxman, Department of Chemistry, Brandeis University, Waltham, MA 02254-9110 USA

How can we use our knowledge of molecular solid-state chemistry, crystal packing, and chemical reactivity to engineer new reactive materials? In recent years, we have designed several solid-state reactions by using structural analogies derived from the Cambridge Structural Database (three examples from organic and inorganic chemistry will be discussed). Following the initial design work, we developed two new series of metal salts and complexes with unique reactivity properties. Solid metal alkynoates and alkenoates undergo oligomerization and polymerization reactions when exposed to ⁶⁰Co _-rays. For example, irradiation of solid sodium trans-2-butenoate leads to a linear trimer, one of eight possible diastereomers, in high yield. Studies of crystalline metal complexes containing such unsaturated ligands provide new insight into solid-state reactivity. In addition to the use of hydrogen bonding and bilayer interactions as agents for the production of reactive phases, changes in metal ion within an isomorphous set of structures may have profound effects on reactivity. We will present recent results which serve to (a) demonstrate the influence of the metal on crystal and molecular structure as well as solid- state reactivity; (b) provide evidence for general reactivity patterns in metal salts of a wide variety of unsaturated carboxylic acids; (c) determine the influence of heavy atoms on the radiation chemistry of crystalline materials. The discussion will include a review of the expanding database of "engineering" reactive molecular crystals, with a view to enhancing previous approaches, as well as developing new strategies.