faculty

Assistant Professor of Chemistry
PhD., Columbia University, New-York;
Postdoctoral, University of California, Berkeley

Theoretical and Computational Chemistry

Phone: 734 647-4495
E-mail: bdunietz@umich.edu

Dunietz Research Group

The understanding of complex systems gained by experimental measurements can be complemented by theoretical models. Computational quantum chemistry (QC) has the ability to provide microscopic insight which is difficult to obtain by other tools. However, the extension of current methodology for such purposes is still far from trivial. The research we plan to undertake, will further enhance the use of QC methodology for complex systems. New methodological extensions required for the study of systems relevant for material science and biology will be suggested and implemented. Focus is provided to investigate processes involved with excited state dynamics of such extended systems.

Biological systems serve as one obvious category of complex systems. Specificly, we are interested in reactions related to photochemistry. Time Dependent DFT (TDDFT) emerges as a highly appropriate method for studying excited states. Recently, TDDFT technology has provided microscopic insight on the relevant excited states of the heme-CO ligand photodissociation process. Other interesting photochemistry reactions will be investigated.

Another category of complex systems that will be considered are related to material science. A major challenge for surface science research is to identify the surface properties which are crucial for catalysis. Electrochemistry is characterized by an additional complexity due to the liquid-solid interface. Microscopic description of the reaction mechanism can be gained by computational tools employing relatively simple models. A recent example is the investigation of the CO electrooxidation process, a well studied model reaction with importance for fuel cell technology. Study of other surface mediated reactions is planned.

A related research effort will be provided to study systems of relevance for molecular electronics. The fundamental unit in molecular electronics consists of a "molecular wire'' (MW) connecting two leads. Upon applying a potential bias on the leads, charge is transferred through the connecting molecule. Even though the idea of MW is ``old'' only recently relevant systems have been treated experimentally. With the success of experiments to measure charge transfer through MWs the need for accurate theoretical models describing these systems has been highlighted. Research in the group will be aimed to devise new methodologies for studying current-voltage relations in molecular junctions as well as applying these methodologies to interesting systems.

Finally, research to extend and improve current QC methodology for investigations of open shell systems is planned. The need for devising low cost and yet qualitative treatments of open shell systems is a well accepted notion. The scheduled research involves method development related to localized perturbation theory and the definition of a family of methods based on the coupled cluster ansatz. The aim is to devise a qualitative reference function, which may be used for higher order corrections

REPRESENTATIVE PUBLICATIONS

1. Wang, J. , Sweeder, R.D., Gottfried, A.C., Kampf, J.W., Dunietz, B.D. and Banaszak~Holl, M.M. 'Aromatic activation of nitrogen and sulfur analogues phenone via Germylene cycloaddition.' Org. Metal., Submitted
2. Prociuk, A., Chen, Y. and Dunietz, B.D. 'Spin-dependent electronic transport through a porphyrin ligated by Fe(II) - an ab-initio study.' Phys. Rev. B., submitted.
3. Dunietz, B.D., Minchul, Y. and Head-Gordon, M. 'Structures of intermediates in cyclohexane dehydrogenation   by surface catalysis - an ab-initio study .' Surface Science , submitted in 05
4. Buda, C., Caskey, S.R., Johnson, M.J.A. and Dunietz, B.D. 'Metathesis-enabled formation of a terminal Ru Carbide complex: A computational study.' Org. Metal ., submitted.
5. Buda, C. and Dunietz, B.D. Hydrogen physisoprtion on the organic linker in metal organic framworks - an ab-initio computational study. J. Phys. Chem. B., accepted.
6. Ugalde, J.M., Dunietz, B., Dreuw, A., Head-Gordon, M. and Boyd, R.J. 'The spin dependence of spatial size of Fe(II) and of the structure of Fe(II)-porphyrins.' J. Phys. Chem. A ., 108 , (2004), 4653--4657.