The quest for technologically useful materials with nanometer-sized features increasingly relies on synthetic innovations to assemble complex supramolecules. The difficulty in creating intricate structures from smaller molecular building blocks is organizing the pieces in specific pre-designed ways. The difficulty increases with complexity, but so do the rewards. Just as the secondary, tertiary, and quaternary elements of structure endow enzymes with enhanced functionality, so development of nanotechnology aims to harness the efficacy beyond the limits of primary covalent interactions. This area of research has recently spawned applications in catalysis, ion exchange, host-guest interactions, molecular magnets, nanoelectronics, and nanomachines.
We build supramolecules by linking inorganic units (atoms or clusters) with organic ligands. We are working to design, synthesize, and characterize coordination networks of arbitrary size, shape, and symmetry by exploiting mathematical constraints and chemical control. Besides encouraging undergraduate students to invent and execute rational synthetic schemes, this interdisciplinary research aims to advance the limits of self-assembly molecular processes.
At left is a hypthetical supramolecule built from 4 nickel(II) cations, 4 pyrazine molecules and 4 2,2'-bipyridine molecules.
Many inorganic coordination compounds are beautifully colored, and some change color with changing temperature. We want to design systems that can change from any color to any other color at a preset temperature. The study of these compounds involves spectroscopy, thermodynamics, and inorganic synthesis.
It is possible through advanced mathematical computations to obtain information about pure chemical compounds in solution without isolating the compounds themselves. This is a huge advantage to studying solution thermodynamics, which we employ in both of the previous research topics listed. We have written computer protocols which take spectrophotometric data of multiple solutions at equilibrium and solve for the molar absorbtivities of all the species in solution and the equilibrium reactions constants for the reactions between them.
Our research is currently funded by the NSF and the ACS Petroleum Research Fund.