Dr. Hans Schanz
Assistant Professor, Organic Chemistry
- Diploma (Chemistry), Universitat Bayreuth, Germany (1995)
- Ph.D. (summa cum laude), Universitat Bayreuth, Germany (1997)
Dr. Hans-Jorg Schanz has received his Diploma (1995) and Ph.D. (1997) from the Universitat Bayreuth in Germany. His Ph.D. research project under the supervision of Prof. Bernd Wrackmeyer was focused on the synthesis and characterization of novel electron-deficient cages made from boron and carbon, so-called carboranes, based on a unique approach using the simultaneous hydroboration/condensation of unsaturated organoboranes. In 1998, he joined the research group of Prof. Steve Nolan at the University of New Orleans as postdoctoral researcher where he investigated the synthesis and catalytic activity of ruthenium-based olefin metathesis catalysts. Here he developed the first general synthetic protocol for the “2nd generation Grubbs-type” catalysts. In 1999, he joined the research group of Prof. Russell Grimes at the University of Virginia on a Feodor-Lynen fellowship sponsored by the Alexander-von-Humboldt Foundation as a postdoctoral associate, where he developed and investigated novel controlled cage-rearrangement reactions of metallacarboranes. The new cages served as model compounds for molecular wires. In his third postdoctoral stint in 2001, Dr. Schanz joined the research group of Prof. Declan Gilheany again at the University College Dublin in Ireland as a Marie-Curie fellow sponsored by the European Union. Here he investigated the stereoselective epoxidation of alkenes with manganese and chromium complexes. He developed a series of new catalysts as well as a combinatorial (high-throughput) approach to the catalyst evaluation. In 2003, he became an Assistant Professor at the University of Southern Mississippi where he developed a research program in “catalysis in alternative media” and “stimuli-responsive catalysis”. His developments yielded a commercial patent application partnered by BASF SE, the world’s largest chemical company, on the first effective emulsion ROMP process for DCPD. Furthermore, he developed the first reversible “on/off” switch for an olefin metathesis reaction and a highly active catalyst class for ring opening metathesis polymerization (ROMP) in aqueous media. In 2011, he joined the Chemistry Department at Georgia Southern University with a research focus on homogeneous catalysis and polymeric materials.
The research in Dr. Schanz’ group ranges from organic and organometallic synthesis to catalysis and material science. At the heart of most research efforts is the development of new homogenous catalysts which can be used, or improve existing processes, in the production of new materials or pharmaceuticals. The design of more capable and applicable catalysts is a highly important task to address the pressing demands of today’s world. Catalysis is at the beginning of many modern materials such as polymers, composites, nanomaterials, etc. which are widely used in light-weight construction, high-performance, environmental and energy applications, and even begin to be growingly used in the biomedical field. Catalysis is also an essential technology for the production of specialty chemicals, most notably fine chemicals and modern pharmaceuticals.
Olefin Metahesis. The redistribution reaction of C=C double bonds based on Ru-based olefin metathesis catalysts has revolutionized modern synthesis in material science and the pharmaceutical industry. For example, the classic problem of synthesizing large cyclic molecules of defined size (so-called macrocycles) via traditional organic synthesis has almost become a “trivial affair” using ring closing metathesis (RCM). Macrocylces hold a tremendous interest as therapeutic targets in the pharmaceutical industry. We are interested in developing catalysts which have a unique and reversibly changeable reactivity or solubility profile based the application of an external stimulus, such as heat, light or a chemical stimulus. There are several current multi-million dollar industries where the advancement of such technologies could generate new markets and applications. Following projects are of interest in our group.
- We have developed the first pH-responsive catalyst system that can be easily removed from the product stream by acidification and subsequent filtration. This is the most efficient removal technology to date for a homogenous olefin metathesis catalyst and could be applied in the pharmaceutical industry, where Ru-contamination in the product stream is a serious and (very noteworthy) costly issue. Currently, our protocol is not efficient enough to reduce the Ru-levels below the pharmaceutical standard. New catalyst designs or Ru-removal protocols are investigated.
- The production of polydicyclopentadiene (poly-DCPD) via ring opening metathesis polymerization (ROMP) is the “Alchemist’s Dream” of turning dirt into gold. DCPD is a waste product of the petrochemical industry, the polymer poly-DCPD is an extremely hard, light-weight and corrosion-resistant high-performance material that has a near-infinite number of applications. Only problem: How can it be produced safely? Once the catalyst and the DCPD are mixed, the highly exothermic reaction can easily get out of control (or the bomb goes off). The real problem is the mixing. We have developed catalysts which are non-reactive and hence, the monomer/catalyst mixture can be processed (e.g. by injection molding) until an external chemical trigger (stimulus) is applied. Then the reaction proceeds as normal. We try to expand the variety of catalysts suitable for this process optimizing key areas such as thermal stability, initiation efficiency and infinite storability.
- Catalysis in water is attractive for many obvious reasons. Water is cheap, vastly abundant, non-toxic and key ingredient to the area of Green Chemistry. The successful transfer of a “classical” organic transformation in organic solvents into an equally efficient transformation in water will have a great positive commercial and environmental impact. There is a very limited number of water-soluble olefin metathesis catalysts known to date. While many of them are not very efficient and active in water, most of them are extremely cumbersome to make and hence way too expensive on top of it. We already have made (to our best knowledge) the most active olefin metathesis catalyst for aqueous applications. Our target is the improvement on the stability of the catalyst.
New Polymeric Materials: The evolution of polymeric materials is the basis for many modern technologies. The structural diversity is based on the development of polymerization techniques with high functional group tolerance, the development of controlled polymerizations and the development and understanding of composites and nanomaterials. Following projects are of interest in our groups.
- We work on the development of a technology which allows us to produce biomolecules such as proteins or DNA with an artificial polymer backbone. These bio-inspired macromolecules then would be non-digestible. Therapies and drugs based on such designs could then be much more efficient and affordable.
- Another project focuses on the development of novel composites and hybrid materials. Of particular interest are composites made from natural materials (e.g. wood) and poly-DCPD combining impact resistance of the natural material with the material strength of the artificial polymer. Applications could range from scratch-resistant wood flooring to “light-weight” armor technology.
- Hydroamination as a polymerization technique is unprecedented thus far. The project targets to design effective catalysts and to use them to synthesize novel polyamine materials with potential applications in the biomedical field.
- CHEM 3341 Organic Chemistry I
- CHEM 3342 Organic Chemistry II
- “Elucidation of Structure”: A senior-level class about the determination of the structure of organic molecules by interpreting IR, UV/Vis, NMR spectroscopy and mass spectrometry analyses.
- Organometallic Chemistry
Selected Publications (undergraduate authors underlined)
- Dunbar, M.A., Balof, S.L., Roberts, A.N., Valente, E.J., Schanz, H.-J.: “pH-Responsive Ruthenium-Based Olefin Metathesis Catalysts: Controlled Ring Opening Metathesis Polymerization in Alcoholic and Aqueous Media upon Acid Addition” Organometallics2011, 30, 199-203.
- Hudson, D.M., Valente, E.J., Schachner, J., Limbach, M., Muller, K.B., Schanz, H.-J.: “A Ru-Vinylvinylidene Complex: Straightforward Synthesis of a Latent Olefin Metathesis Catalyst” Chem. Cat. Chem. 2011, 3, 297-301.
- Dunbar, M.A., Balof, S.L., LaBeaud, L.J., Yu, B., Lowe, A.B., Valente, E.J., Schanz, H.-J.: “Improved Molecular Weight Control in Ring Opening Metathesis Polymerization Reactions with Ru-Based Olefin Metathesis Catalysts Using N-Donors and Acid: A Kinetic and Mechanistic Investigation” Chem. Eur. J. 2009, 15, 12435-12446.
- Balof, S.L., Yu, B., Lowe, A.B., Ling, Y., Zhang, Y., Schanz, H.-J.: “Ru-Based Olefin Metathesis Catalysts Bearing pH-Responsive N-Heterocyclic Carbene (NHC) Ligands: Activity Control via Degree of Protonation” Eur. J. Inorg. Chem. 2009, 1717-1722.
Awards & Recognitions
- Aubrey Keith Lucas and Ella Ginn Lucas Endowment for Faculty Excellence Award, University of Southern Mississippi (2007)
- University Summer Faculty Research Award, University of Southern Mississippi (2004)
- Marie-Curie-Host-Development Fellowship Award, European Union (2001-2003)
- Feodor-Lynen Postdoctoral Fellowship, University of Virginia (1999-2000)
Last updated: 5/27/2014