Prof. Kraig A. Wheeler - Department of Chemistry

Molecular Topology, Crystal Engineering, Functional Materials, Intermolecular Forces (e.g., Hydrogen Bonds), X-Ray Crystallography, Molecular Recognition Processes, Supramolecular and Structural Chemistry

One remaining Holy Grail in Science is the prediction of material structure based solely on chemical composition. Since the physical properties of materials e.g. color, magnetism, solubility, molecular recognition behavior etc., originate from the organization of the fundamental building blocks (atoms and molecules), an intimate understanding of the forces that determine material structure is of great importance. Data from single-crystals (materials with three-dimensional periodicity) has provided a natural starting point for many investigations in this area. Serious thought has been given to this area and efforts to engineer molecular alignment (and other materials) remain the focus of many investigations. Unfortunately, predictions of crystal structures from knowledge of chemical composition of the fundamental components are far from being realized by intuition, by design, or by other physical principles. The difficulty with controlling molecular assemblies stems from an insufficient assignment of all crystal-packing contributors and a lack of understanding of the specificity of recognized intra- and intermolecular interactions. Ongoing projects in Dr. Wheeler's laboratory seek to control and predict the self-assembly of molecules into extended networks. Program objectives include:

Exploiting molecular shape as a design tool for the construction of predictable structural aggregates;
Constructing crystalline architectures with functional properties (e.g. nanoporous and NLO materials);
Exploring the hydrogen bond specificity of chemical systems with multiple acceptor and donor groups; and
Investigating the interplay of strong and weak crystal cohesion forces.

J.R. Bowers, G.W. Hopkins, G.P.A Yap, K.A. Wheeler "Structural consequences of strong and weak interactions to binary benzoic acid/bipyridine supramolecular assemblies," Crystal Growth and Design 2005, 5, 727-736.

A. Sniady, K.A. Wheeler, R. Dembinski. "5-Endo-dig electrophilic cyclization of 1,4-disubstituted but-3-yn-1-ones: regiocontrolled synthesis of 2,5-disubstituted 3-bromo- and 3-iodofurans," Organic Letters (Communication) 2005, 7, 1769-1772.

M. Hendi, P. Hooter, V. Lynch, R.E. Davis, K.A. Wheeler "Structural studies of enantiomers, racemates, and quasiracemates. N-(4-methylbenzoyl)methylbenzylamine and N-(4-nitro-benzoyl)methylbenzylamine," Crystal Growth and Design 2004, 4, 95-101.

K.A. Wheeler, B. Harrington, M. Zapp, E. Casey "Competitive N-H···O=C and N-H···S=C hydrogen bonding in alanine dithiocarbamates," Crystal Engineering Communications 2003, 5, 337-342.

P. Ayyappan, O.R. Evans, Y. Cui, K.A. Wheeler, W. Lin "Nonlinear optically active polymeric coordination networks based on metal m-pyridylphosphonates," Inorganic Chemistry 2002, 41, 4978-4980.

S. Fomulu, M. Hendi, R.E. Davis, K.A. Wheeler "Structural studies of enantiomers, racemates, and quasiracemates. N-(2-chlorobenzoyl)methylbenzylamine and N-(2-bromo-benzoyl)methylbenzylamine structural studies of enantiomers, racemates, and quasiracemates," Crystal Growth and Design 2002, 2, 637-644.

S. Fomulu, M. Hendi, R.E. Davis, K.A. Wheeler "Structural studies of enantiomers, racemates, and quasiracemates. 2-(2,4,5-trichloroanilino)propanoic acid and 2-(2,4,5-trichloro-phenoxy)propanoic acid," Crystal Growth and Design 2002, 2, 645-651.

P. Ayyappan, O.R. Evans, B.M Foxman, K.A. Wheeler, T.H. Warren, W. Lin "New open frameworks based on pyridylphosphonates," Inorganic Chemistry 2001, 40, 5954-5961.