Solid-State Reactions of Molecular Crystals

Brandeis University, Waltham MA

Investigators

Abstract

The objectives of the proposed research focus on the design, discovery and characterization of new solid-state reactions. First, expansion of an initial set of target molecules to include groups with terminal double bonds as well as cationic metal complexes with neutral unsaturated ligands will both (a) promote the discovery of new processes, and (b) aid in the efficient selection of those materials likely to produce stereoregular products. Crystallographic studies, as well as full product characterization, will develop understanding of the geometrical and chemical mechanism associated with each process. Second, when single crystals are not available, structures will be determined by powder diffraction techniques. In addition to studies of new materials, powder X-ray structure determination of extant solid-state polymerization systems, such as potassium acrylate, will provide significant new information for a structure-reactivity database. Third, analysis of the diffuse X-ray scattering observed during the course of a solid-state reaction will provide new information on the disorder observed to occur at intermediate stages of solid-state reactions. Fourth, a series of molecular solids ranging from cinnamic acids to metal complexes will be irradiated in the low-energy "tail" of the absorption band of the corresponding chromophore. This avenue of research promises to produce single crystals of dimers, oligomers and polymers. Finally, newly-synthesized metal salts of acetylenedicarboxylic acid promise to be excellent prospects for new applications involving radiation dosimetry. %%% Solid state reactions offer exceptional opportunities for chemospecific and stereo specific synthesis leading to the production of new oligomers and polymers, and the discovery of novel applications for new materials in technological areas such as dosimetry and solid phase peptide synthesis are viewed as high priorities in industry.