Polymorphism of Organic Materials

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This award to University of Wisconsin-Madison by the Solid State Materials Chemistry program in the Division of Materials Research is to investigate the polymorphism of organic materials. Polymorphism is the ability of the same molecule to crystallize in different structures with distinct properties, as the ability of carbon to crystallize as diamond, graphite, and C60. This project will synthesize novel polymorphs by cross-nucleation and will use polymorphs to understand an unusual mode of crystal growth from amorphous solids. The project builds on recent observations that rare crystal forms of chiral molecules may be discovered by seeding and that some polymorphs show fast, diffusionless crystal growth from the glassy state, while others do not. This project will study two broad fundamental questions in the crystallization of organic and pharmaceutical materials: (i) synthesis of solid solutions of enantiomers, with an enhanced excess of one enantiomer, and (ii) the crystallization of amorphous materials. The first project focuses on the seeding-induced crystal growth of chiral molecules. The second part of the project will be on the crystal growth of polymorph-forming molecules from supercooled liquids. Both projects seek to address fundamental mechanisms of crystal growth. Studying crystal polymorphs serve two missions of materials research: to synthesize new materials and to understand structure-property relations. It is anticipated that this research will impact several technological areas. The discovery and control of polymorphs is critical in developing drugs, pigments, explosives, and other materials. Better understanding of the crystallization of amorphous materials will advance the ability to develop amorphous drugs, silicon, metals, ceramics, and polymers. This research spans materials science and chemistry and will provide multidisciplinary educational opportunities for undergraduate and graduate students. The research will involve students from the Undergraduate Research Scholars program, which helps first- and second-year undergraduates to gain hands-on experience in research by working with the faculty and research staff at University of Wisconsin-Madison campus.