Dr. Christina Römelt - Chemical Synthesis

Dr. Christina Römelt
Leiterin der Gruppe Chemical Synthesis
Abteilung Anorganische Spektroskopie

Vita

Studium (Chemie)Universität Bonn (2003-2008)
Diplom (organische Chemie)Universität Bonn (2008)
Promotion (organische Chemie)Universität Bonn (2008-2010), Universität Mainz (2010-2013)
ForschungsprojektNovartis, Basel (2013)
Wiss. MitarbeiterinMPI CEC (2014-2017)
GruppenleiterinChemical Synthesis, MPI CEC (seit 2017)

Publikationen

C. Römelt, J. Song, M. Tarrago, J. A. Rees, M. van Gastel, T. Weyhermüller, S. DeBeer, E. Bill, F. Neese and S. Ye, Inorganic Chemistry, 2017, 56, 4745-4750.

C. Römelt, S. Ye, E. Bill, T. Weyhermüller, M. van Gastel and F. Neese, “Electronic Structure and Spin Multiplicity of Iron Tetraphenylporphyrins in Their Reduced States as Determined by a Combination of Resonance Raman Spectroscopy and Quantum Chemistry”, manuscript in preparation.

C. Guetz, M. Selt, M. Baenziger, C. Bucher, C. Roemelt, N. Hecken, F. Gallou, T. R. Galvao, S. R. Waldvogel, Chem. Eur. J. 2015, 21, 13878-13882.

C. Lohoelter, M. Brutschy, D. Lubczyk, S. R. Waldvogel, Beilstein J. Org. Chem. 2013, 9, 2821-2833.

C. Lohoelter, M. Weckbecker, S. R. Waldvogel, Eur. J. Org. Chem. 2013, 25, 5539-5554.

C. Lohoelter, D. Schollmeyer, S. R. Waldvogel, Eur. J. Org. Chem. 2012, 32, 6364-6371.

A. Shah, Z. Khan, N. Choudhary, C. Lohoelter, S. Schafer, G. Marie, U. Farooq, B. Witulski, T. Wirth, Org. Lett. 2009, 11, 3578-3581.

Gruppenmitglieder

Chemical Synthesis

Due to the vast employment of carbon-based fuels in combustion processes, the amount of CO2 in the atmosphere has increased by almost 40% over the last hundred years. The research of my group is focused on the reconversion of CO2 into building blocks which can be employed for further use (formaldehyde, formic acid, oxalic acid, methanol, CO). Due to its thermodynamic stability, the electrochemical reduction of CO2 to the CO2●– radical (E0´= –1.90 V) has to be facilitated by using suitable catalysts. Iron tetraphenylporphyrins (FeTPP´s) in the presence of external or internal proton sources are reported to exhibit one of the highest catalytic activities and turnover frequencies observed so far.1-5

Since the nature of the electronic ground state of the catalytically active species [FeTPP]2– has been controversially discussed for decades, we focused on the elucidation the electronic structure of these compounds by employing a combination of spectroscopy and theory, with both Mössbauer and XAS spectroscopic results supporting ligand reduction (Fig. 1).6

Furthermore, the synthesis of novel catalysts and investigation of their efficiency in the electrochemical CO2 reduction are topic of our current research. Our approach is the design of new TPP systems providing optimized substituents to a) stabilize the CO2-Fe moiety by strong hydrogen bonds and b) to donate protons more easily by using substituents with a low pKa value. Fe-CO2 adduct stabilization might lead to an even greater enhancement of the catalytic activity and/or the opportunity to stabilize this species for further characterization which hopefully gives insight into this very crucial step in catalysis. In a first attempt, we have synthesized a new TPP ligand system carrying four sulfonamide groups (Fig. 2). Iron insertion will then render a promising candidate for catalysis.

References

1. I. Bhugun, D. Lexa and J. M. Saveant, J. Am. Chem. Soc. 1996, 118, 1769 - 1776.

2. M. Hammouche, D. Lexa, J. M. Saveant and M. Momenteau, J. Electroanal. Chem. Interfacial Electrochem. 1988, 249, 347-351.

3. C. Costentin, S. Drouet, G. Passard, M. Robert and J. M. Saveant, J. Am. Chem. Soc. 2013, 135, 9023-9031.

4. C. Costentin, G. Passard, M. Robert and J. M. Saveant, P. Natl. Acad. Sci 2014, 111, 14990 - 14994.

5. C. Costentin, G. Passard, M. Robert and J. M. Saveant, J. Am.Chem. Soc. 2014, 136, 11821-11829.

6. C. Roemelt, J. Song, M. Tarrago, J. A. Rees, M. van Gastel, T. Weyhermueller, S. DeBeer, E. Bill, F. Neese and S. Ye, Inorg. Chem. 2017, 56, 4745-4750.