סמינר כימיה אורגנית ואי-אורגנית
מרצה: Professor Peter Comba
מיקום: חדר סמינרים פקולטי
New reaction channels with nonheme iron oxidation catalysts
Universität Heidelberg, Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing (IWR), Im Neuenheimer Feld 270, 69120 Heidelberg, Germany http://www.uni-heidelberg.de/comba-group
Bispidine ligands are extremely rigid, easy to synthesize and available in a large variety. They enforce coordination geometries derived from cis-octahedral, and the two vacant coordination sites with the tetradentate ligand systems are sterically and electronically distinct; with the isomeric pentadentate ligands, the site of the oxo group is enforced by the ligand (see Figure). Coligands coordinated trans to N3 generally have strong and short bonds, those trans to N7 are more labile. Reasons are thoroughly analyzed on the basis of computational work as well as experimental structural data, thermodynamics, spectroscopy and reactivities. Implications with respect to the mechanism of formation and decay and the structure and spin state of high valent iron oxidants are analyzed, and possibilities to tune the spin state, structure and reactivity of high valent iron complexes are discussed.1-3
Examples that will be discussed are the halogenation of alkanes (the modeling of halogenase activity), the electronics of the FeIV=O bond (spin state of iron and radical character of the oxo group) as well as a novel environmentally important reaction, the anaerobic formation of methane from methionine and from acetic acid.
1 Comba, P.; Kerscher, M.; Schiek, W. Progr. Inorg. Chem., 2007, 55, 613-704.
2 Comba, P.; Kerscher, M.; Krause, T.; Schöler, H. F. Env. Chem. 2015, 12, 381-395.
3 Comba, P.; Kerscher, M.; Rück, K.; Starke, M. Dalton (Perspective). 2018, 47, 9202-9220.