Research Interests of James D. Martin
Condensed Matter Inorganic Chemistry:
Structure, Properties, and Reaction Mechanisms
The ability to design materials tailored to exploit chemical and structure/property relationships is fundamentally important to the development of advanced materials. In the Martin group, we are particularly interested in novel materials for catalytic, sorption, optical, magnetic and electronic applications. Our research efforts are focused in four primary areas including crystal engineering, amorphous materials engineering, the reactivity of small molecules with crystalline solids, and understanding the mechanisms of crystal growth.
Exploiting fundamental principles of structure and bonding, we develop strategies to construct novel metal-halide materials, for example, metal halide analogs of zeolites. These frameworks are constructed with redox-active and strongly Lewis acidic metal centers to enhance their reactivity toward small molecules. Frameworks with unique luminescent electronic and magnetic properties are also designed.
Liquids and glasses have long been understood by scientists to be amorphous, meaning without structure. However, far from being without structure, our research involving calorimetry, NMR spectroscopy, and synchrotron and neutron diffraction is demonstrating that it is possible to design specific structures in amorphous materials over nanometer length scales. Application of principles of crystal engineering to the understanding and control of glass and liquid structure is creating the entirely new field of Amorphous Materials Engineering, including the creation of some of the most metal-rich liquid crystal phases known.
The reactivity of small molecules with crystalline solids is critically important for molecular separations and catalysis. We have developed crystalline materials that demonstrate a remarkable capacity for the sorption of olefins, carbonyls and aromatics, and also provide for their separation from saturated organics. Current research efforts seek to understand the fundamental reaction mechanisms of how small molecules react with crystalline solids. Using time resolved synchrotron diffraction and spectroscopic experiments, we have uncovered remarkable sorptive reconstruction mechanisms that provide insight for the creation of novel catalysts.
The mechanism by which crystals grow from their melts is of great importance to everything from an understanding of how ice clouds form in the atmosphere to the growth of pure crystalline materials for electronic and optical applications. Nevertheless, little is known regarding the atomic-level mechanisms by which crystals grow. Exploiting knowledge gained from our studies of liquids and crystals, we have developed systems in which we can separate nucleation and growth components of crystallization reactions. Working under conditions where nucleation is slow and growth is fast, we are able to achieve rapid single crystal growth. Our ability to independently measure the rates of crystal nucleation and growth is giving a new perspective on classic theories of crystal nucleation and growth.