John J. Stezowski
Professor
Hamilton Hall 525
402.472.8570
jjs@unlserve.unl.edu
Faculty & Research | Faculty Directory | Recent Publications
Figure 1
Current Research
Single crystals, ab initio calculations, frontier orbitals, molecules at atomic resolution, bio-organic systems, molecular recognition, solid state dynamics.
A primary goal for chemists is to understand the interrelationships between structure and the chemical and physical properties of matter. The systems of interest cover a broad spectrum ranging from materials used in modern electronics, to a variety of biochemical processes. X-ray crystallography is arguably the most powerful tool available today to study these problems. It is most powerful when complemented by other structural techniques especially molecular modeling and NMR in both the solution and solid states.
Figure 2
The StezLab, Professor Stezowski's Group, has used single crystal studies to study a broad range of chemical systems. The most recent and continuing focus is on β-cyclodextrin supramolecular inclusion complexes. These studies are designed to reveal information on molecular and chiral recognition and/or photochemical reaction processes.
Figure 3
The figures presented here display three examples of these studies: Figure 1 is a supramolecular complex with two molecules of the peptide derivative N-acetyl-L-phenylalanine methyl ester included in a β-cyclodextrin hydrogen bonded dimer host system. Figure 2 displays Ab initio theoretical calculations on the guest molecules designed to further characterize the intermolecular interactions involved by depicting electrostatic potential diagrams calculated based on the crystal structure results. Figure 3 illustrates a study of chemical reactions in nanoscale reaction vessels (the inclusion complex) in which there is a crystal to crystal solid-state photochemical reaction.
A collaboration bringing solid state dynamics by temperature dependent NMR studies into the research program has been established with scientists at the College of William and Mary, Williamsburg, VA.
- X-ray Crystal Structure Determination
- Ab Iinitio Calculations
- Molecular recognition
- Frontier Orbitals
- Oder-Disorder in crystals
- High resolution crystallography
- Temperature dependent crystallography
- Supramolecular complexes
- Crysta-crystal solid state reactions
A graduate student or post doctoral associate in StezLab can expect to receive training in single crystal structure determination using unconventional as well as classical techniques, to use the results of crystal structure determinations to initiate ab initio calculations to study molecular recognition. Topics of interest are medicinally important organic compounds and supramolecular complexes that serve as reaction vessels in solid state chemical reactions or are suitable models for the study of molecular recognition.
