Contact

Areas of Research
Projects
Collection of Figures
References

Molecular Modeling

Areas of Research

• Oxygen activation, oxidation catalysis, biomimetic nonheme iron chemistry Peter Comba, Marion Kerscher, Bodo Martin, Julie Lefebvre, Steffen Wunderlich, Martin Maurer, Sebastian Wiesner, Prabha Vadivelu, Amsaveni Muruganantham
• New rigid ligands, radiopharmaceutical chemistry, molecular sensors Peter Comba, Marion Kerscher, Christina Haaf, Lena Daumann Copper
• Coordination chemistry of cyclic peptides, structures in solution, EPR spectroscopy, CO2 fixation Peter Comba, Nina Dovalil
• Purple acid phosphatase model chemistry, EPR spectroscopy Peter Comba, Bodo Martin, Marta Zajaczkowski
• Single-molecule magnetism Peter Comba, Bodo Martin, Mihail Atanasov, Sascha Hausberg, Christoph Busche, Stefan Helmle
• Reinforced macrocyclic ligands Marion Kerscher Molecular mechanics program and force field development Bodo Martin

 

Projects

Our group is interested in classical transition metal coordination chemistry as well as theoretical inorganic chemistry and molecular modeling. The basis of all our projects is to distort the coordination geometries to yield compounds with specific electronic properties, reactivities and thermodynamic properties.

The experimental work (ligand synthesis, preparative coordination chemistry, structural studies, spectroscopy, magnetism, electrochemistry and investigation of stabilities and reactivities) is supported by theoretical studies (force field calculations, ligand field calculations, spectra simulations, DFT and various combined approaches), aiming at understanding molecular structures and properties in order to correlate (interpretation) and predict them (design).

One of the central questions in our projects is how ligands can enforce a specific structure and how this may lead to specific molecular properties. Important features in the continuum including an optimum fit between the ligand and the metal center and an extreme misfit, are the entatic state principle, preorganization and complementarity. The combined experimental-computational ap­proach is also the basis of the DFG-funded graduate college 850 (modeling of molecular properties, http://www.molmod.uni-hd.de/)

 

Collection of Figures

Fig. 1 Mechanism of the catalytic dihydroxylation (right) and epoxidation (left) of olefins by a tetradentate bispidine ligand oxo-iron(IV) complex.

Fig. 2 The 64Cu complex of the bombesin derivative of a tetradentate bispidine ligand has been developed for tumor diagnostics.

Fig. 3 Structure of the carbonate-bridged dicopper(II) com­plex of the cyclic peptide ascidiacyclamide.

Fig. 4 Computed anisotropy gap of dinuclear (CN)5FeIII­CN-NiIIL complexes as a function of the Jahn-Teller induced trigonal distortion of the hexacyanoferrate(III) subunit.

 

References

[2] Comba, P.; Kuwata, S.; G. Linti, H. Pritzkow, Tarnai, M.; Wadepohl, H. J. Chem. Soc.,
Chem. Commun., 2006, 2074-2076 ’Oxidative N­dealkylation in cobalt-bispidine-H2O2 systems

[3] Atanasov, M.; Comba, P.; Martin, B.; Müller, V.; Rajaraman, G.; Rohwer, H.; Wunderlich, S. , J. Comput. Chem., 2006, 27, 1263. ’DFT models for copper(II) bispidine complexes: Structures, stabilities, isomerism, spin distribution and spec­troscopy.’

[4] Bautz, J.; Bukowski, M. R.; Stubna, A.; Kerscher, M.; Lienke, A.; Comba, P.; Mnck, E.; Que Jr., L. Angew. Chem., 2006, 118, 5810; Angew. Chem. Int. Ed. 2006, 45, 5681. ’Aqueous oxo­iron(IV) formation at pH 2-6 from a nonheme iron(II) complex and H2O2.’

[5] Born, K.; Comba, P.; Daubinet, A.; Fuchs, A.; Wadepohl, H. J. Biol. Inorg. Chem., 2007, 12, 36.
’Catecholase activity of dicopper(II) bispidine complexes: stabilities and structures of intermediates, kinetics and reaction mechanism.’

[6] Bautz, J.; Comba, P.; Lopez de Laorden, C.; Menzel, M.; Rajaraman, G. Angew. Chem., 2007, 46, 8067. ’Biomimetic high-valent non-heme iron(IV) oxidants for the cis-dihydroxylation and epoxidation of olefins.’

[7] Atanasov, M.; Comba, P.; Daul, C. A. Inorg. Chem. 2008, 47, 2449. ’A combined ligand field and density functional theory analysis of the magnetic anisotropy in oligonuclear complexes based on FeIII-CN-MII exchange-coupled pairs.’

[8] Comba, P.; Gahan, L. R.; Haberhauer, G.; Hanson, G. A.; Noble, C. J.; Seibold, B.; van den Brenk, A. L. Chem. Eur. J. 2008, 14, 4393. ’Copper(II) coordination chemistry of Westiellamide and its imidazole-, oxazole-and thiazol analogues.’

[9] Comba, P.; Lang, C.; Lopez de Laorden, C.; Muruganantham, A.; Rajaraman, G.; Wadepohl, H.; Zajaczkowski, M. Chem. Eur. J. 2008, 14, 5313. ’The mechanism of the bispidinecopper-catalized aziridination of styrene. A combined theoretical and experimental study.’

[10] Comba, P.; Kerscher, M.; Lawrance, G. A.; Martin, B.; Wadepohl, H.; Wunderlich, S. Angew. Chem. Int. Ed. 2008, 47, 4743. ’Stable five-and six-coordinate cobalt(III) complexes with a pentadentate bispidine ligand.’