Current Projects

Research Areas: Organic chemistry, materials science, liquid crystals, molecular magnetism and electronics, synthesis of main group heterocycles, strained molecules, free radicals, quantum mechanical calculations.

Our research addresses basic and applied problems and concentrates in three major areas of advanced organic materials. We design, synthesize, and characterize materials for optoelectronic applications, nanoscale construction, molecular electronics, and radical-containing liquid crystals for studying molecular magnetism. The desired electronic effects in organic molecules are engineered using main group elements such as B, Si, N, P, and S. Each project involves extensive computer-aided design of molecular systems, synthesis and study of the new materials, and comparison of the experimental results with the theoretical predictions.

One of our group's major strengths is our considerable expertise in organic synthesis and in the properties of liquid crystals. We design new materials for display applications and also we use liquid crystallinity as the vehicle to study electronic and magnetic phenomena. We have also developed a good level of understanding of semi-empirical and ab initio computational methods which allow us to predict molecular properties and also to choose synthetic targets for study.

Liquid Crystalline Radicals

The centerpiece of our design of this class of unprecedented materials is the thioaminyl radical fragment which can be easily incorporated into aromatic rings and thus into the rigid cores of a variety of mesogenic molecules. The design is general and, in principle, allows for engineering of almost all types of liquid crystalline phases and the study of electronic and magnetic phenomena in semiordered media. The p-delocalization of the spin and typical strong core-core interactions are expected to promote intermolecular spin-spin interactions in the mesogenic state. Using these materials, we hope to test the theory that molecular organic magnetism may be achieved through partially oriented fluids.

Boron-containing Liquid Crystals

We are actively developing liquid crystalline materials with large positive dielectric anisotropies for applications in flat panel displays. The dielectric anisotropy is related to the distribution of dipole moments within the molecule and is essential for the electrooptical effect in liquid crystal displays in calculators, laptop computers, etc. An electron deficient boron atom and its highly polar bonds in tetra- and higher-coordinated boron compounds are at the heart of our design. We are pursuing the challenging synthesis of 1-borabicyclo[2.2.2]octane and its complexes with amines and pyridines. We are also exploring boron closo-clusters, such as p-carborane, as novel structural elements of liquid crystalline molecules. Our quantum-mechanical calculations suggest that some of these derivatives may also have very large dipole moments oriented along the long molecular axes.

Building Blocks for Molecular-scale Construction Sets

Nanotechnology and molecular electronics are rapidly growing interdisciplinary fields. However, there is a gap between the designs for nanodevices and available molecular building elements. Our goal is to fill this gap by providing rationally designed molecules, which would serve either as supportive elements, or as active components in molecular assembles. In our lab, we work on challenging ring systems with unique geometries. Incorporation of silicon atoms to some polycyclic systems allows us to systematically perturb the electronic molecular structure and to alter chemical reactivity. As a result, these systems make attractive spacers for the construction of a molecular diode, a molecular shift register, or for the study of electron transfer processes in general.

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