ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P25. New Model Systems for Binuclear Nonheme Iron-Oxo Proteins
B. Burger a , S. Wöckel a , M. Jarenmark b , S. Dechert a , E. Nordlander b , F. Meyer a
a Institute for Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077, Göttingen, Germany
e-mail: boris.burger@chemie.uni-goettingen.de
b Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00, Lund, Sweden
Binuclear nonheme Iron-oxo proteins are widespread in nature and possess a variety of biochemical functions
[1]. Most of the carboxylate-bridged diiron active centers of those proteins can actually react with, and activate
dioxygen. Certain organisms use that in, e. g., dioxygen carrier proteins like Hr, others make use of it to perform
impressive oxygenation reactions of biological substrates [2]. The interest to develop model systems for those
diiron-proteins is of course enormous [3], but there is still need to design suitable ligands to reach functionality.
Therefore nature is the best archetype.
The active center of, e. g., the enzyme Methane Monooxygenase in its reduced state is a diferrous core ligated by
histidine and carboxylic residues from surrounding amino acids. Moreover, most of the diiron active centers
have a ligation that is comprised by only histidine- and carboxylic residues of glutamate or aspartate, so they
exhibit Nitrogen and Oxygen donor atoms in the ligand sphere [1].
The actual work presents some newly developed Pyrazole-based ligands, which have the potential to mimic the
natural ligation of the carboxylate-bridged diiron active centers. Therefore we have designed different sidearms
for the Pyrazole, which comprise either Imidazole- or aliphatic Nitrogen donor atoms as well as a carboxylic
residue. Here we present some of the initial results on the way to functional biomimetic diiron-oxo complexes.
References:
[1] D. M. Kurtz Jr., J. Biol. Inorg. Chem. 1997, 2, 159.
[2] A. L. Feig, S. J. Lippard, Chem. Rev. 1994, 94, 759.
[3] E. Y. Tshuva, S. J. Lippard, Chem. Rev. 2004, 104, 987.
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