Departmental Seminar
Department of Chemistry
Ben-Gurion University of the Negev
Monday, November 25, 2013
Time 00:11
Bldg. 51 Room 15
Prof. Karsten Meyer
Department of Chemistry and Pharmacy, Inorganic Chemistry
Friedrich-Alexander-University Erlangen-Nuremberg
Erlangen – Nuremberg, Germany
"Small Molecule Activation at Reactive Metal Complexes:
From Nuclear Fuels to CO2 Activation at Uranium Complexes –
Chemistry Between Phobia & Enthusiasm"
Ingrid Castro-Rodriguez, Hidetaka Nakai, Suzanne C. Bart, Oanh P. Lam, Stephan J. Zuend,
Hajime Kameo, Henry S. LaPierre, Dominik Halter, Frank W. Heinemann and Karsten Meyer
Uranium and, its in traces existing heavier neighbor, plutonium, are the heaviest naturally occurring elements, and they share one
common thing with each other: they undeniably have the worst reputation of all elements of the periodic table. Negative
connotations through news on warlords and nuclear reactor catastrophes fuel the fear to handle and manipulate the element
uranium; even within the scientific community. However, human life on earth would not exist, and
the exploration of the far universe would not be possible without natural radioactivity. In this lecture,
a general introduction is given on how radioactivity of naturally abundant and man-made elements, in
e.g. plutonium-powered heart pacemakers and satellites, impact our modern life. A brief tour through
basic inorganic chemistry shows how pitchblende is transformed into modern nuclear fuels, how
organometallic chemists have discovered the element for basic chemical research, and how this field
has sparked new discoveries of current interest ever since. In our efforts to activate small molecules of
industrial and biological concern, we have turned our attention to coordinatively unsaturated, reactive
uranium coordination complexes. For example, the chelating triazacyclononane, single N, and areneanchored tris- (aryloxide) ligands, (ArO)3tacn3–, (ArO)3N3–, and (ArO)3mes3– have provided access to
reactive coordination compounds of uranium in oxidation states “II”, III, IV, V, and VI with tailorable
steric profiles. These complexes display a pronounced selectivity and reactivity in reactions with carbon dioxide, related small
heteroallene molecules, and even the elemental chalcogens S, Se, and Te. As a result, they provide unique reaction pathways
inaccessible to traditional transition metal chemistry. In this seminar will be presented our work on CO 2 activation, including
unprecedented coordination modes, stoichiometric reductive cleavage, insertion and functionalization reactions. Most recently, we
reported the stoichiometric and catalytic “disproportionation” of CO 2 to CO and CO3 2– via reductive cleavage of CO2, yielding a
μ-oxo bridged complex, followed by the insertion of another molecule CO2. In a similar strategy, we were able to isolate and
characterize several mixed carbonate complexes U-CO2E-U, U-CS2E-U, and even U-OC(S)Se-U by reacting bridged
chalcogenide complexes U-E-U (E = S, Se) with CO2, CS2, and COS. These chalcogenido mixed-carbonate complexes represent
the first of their kind.
Leading References:
[1] O. P. Lam, S. Franke, F. W. Heinemann and K. Meyer in J. Am. Chem. Soc. 2012, 134, 16877.
[2] A.-C. Schmidt, A.V. Nizovtsev, A. Scheurer, F.W. Heinemann and K. Meyer in Chem. Commun. 2012 , 48, 8634 – 8636.
[1] S.J. Zuend, O.P.Lam, F.W. Heinemann and K. Meyer in Angew. Chem., Int. Ed. 2011, 50, 10626. VIP paper
[2] O.P. Lam, F.W. Heinemann and K. Meyer in Angew. Chem., Int. Ed. 2011, 50, 5965.
[3] O. P. Lam, S.C. Bart, F.W. Heinemann and K. Meyer in Chem. Commun. 2010,46, 3137.
[4] A.R. Fox, S.C. Bart, C. Anthon, K. Meyer and C.C. Cummins in Nature 2009, 455, 341.
[5] S.C. Bart, F.W. Heinemann, E. Bill, N.M. Edelstein and K. Meyer in J. Am. Chem. Soc. 2008, 130, 12536.
[6] I. Castro-Rodriguez and K. Meyer in J. Am. Chem. Soc. 2005, 127, 11242.
[7] I. Castro-Rodriguez, H. Nakai, L. Zakharov, A.L. Rheingold and K. Meyer in Science 2004, 305, 1757.