Dr. Thomas Weyhermüller - Chemical Synthesis, X-ray structure analysis

Dr. Thomas Weyhermüller
Head of Group Chemical Synthesis, X-ray structure analysis
Department Inorganic Spectroscopy


Diploma (Chemistry)Ruhr-University Bochum (1989)
Ph.D. and staff scientistRuhr-University Bochum (1990-1994)
Dr. rer. nat.Ruhr-University Bochum (1994)
Group leaderMPI CEC (former MPI for Bioinorganic Chemistry) (since 1995)


Full publications list | ORCID | ResearcherID

Selected MPI CEC publications

  • Shit, M., Maity, S., Bera, S., Kumar Mudi, P., Biswas, B., Weyhermüller, T., Ghosh, P. (2021). Nickel (II) di-aqua complex containing water cluster: Synthesis, X-ray structure and catecholase activity New Journal of Chemistry https://doi.org/10.1039/D0NJ05238H
  • Voit, G., Jenthra, S., Hölscher, M., Weyhermüller, T., Leitner, W. (2020). Reversible Insertion of Carbon Dioxide at Phosphine Sulfonamido PdII–Aryl Complexes Organometallics 39(24), 4465-4473. https://doi.org/10.1021/acs.organomet.0c00560
  • Levin, N., Peredkov, S., Weyhermüller, T., Rüdiger, O., Pereira, N.B., Grötzsch, D., Kalinko, A., DeBeer, S. (2020). Ruthenium 4d-to-2p X-ray Emission Spectroscopy: A Simultaneous Probe of the Metal and the Bound Ligands Inorganic Chemistry 59(12), 8272-8283. https://doi.org/10.1021/acs.inorgchem.0c00663
  • Cramer, H.H., Chatterjee, B., Weyhermüller, T., Werlé, C., Leitner, W. (2020). Controlling the Product Platform of Carbon Dioxide Reduction: Adaptive Catalytic Hydrosilylation of CO2 Using a Molecular Cobalt(II) Triazine Complex Angewandte Chemie International Edition 59(36), 15674-15681. https://doi.org/10.1002/anie.202004463
  • Erken, C., Hindemith, C., Weyhermüller, T., Hölscher, M., Werlé, C., Leitner, W. (2020). Hydroamination of Aromatic Alkynes to Imines Catalyzed by Pd(II)–Anthraphos Complexes ACS Omega 5(15), 8912-8918. https://doi.org/10.1021/acsomega.0c00562
  • Dutta, D., Kundu, S., Weyhermüller, T., Ghosh, P. (2020). Metal promoted conversion of aromatic amines to ortho-phenylenediimine derivatives by a radical coupling path Dalton Transactions 49(16), 5015-5019. https://doi.org/10.1039/D0DT00089B
  • Dinda, S., Patra, S.C., Roy, S., Halder, S., Weyhermüller, T., Pramanik, K., Ganguly, S. (2020). Coligand driven diverse organometallation in benzothiazolyl-hydrazone derivatized pyrene: ortho vs peri C–H activation New Journal of Chemistry 44(4), 1407-1417. https://doi.org/10.1039/c9nj05088d
  • Yogendra, S., Weyhermüller, T., Hahn, A.W., DeBeer, S. (2019). From Ylides to Doubly Yldiide-Bridged Iron(II) High Spin Dimers via Self-Protolysis Inorganic Chemistry 58(14), 9358-9367. https://doi.org/10.1021/acs.inorgchem.9b01086
  • Kalläne, S.I., Hahn, A.W., Weyhermüller, T., Bill, E., Neese, F., DeBeer, S., van Gastel, M. (2019). Spectroscopic and Quantum Chemical Investigation of Benzene-1,2- dithiolate-Coordinated Diiron Complexes with Relevance to Dinitrogen Activation Inorganic Chemistry 58(8), 5111-5125. https://doi.org/10.1021/acs.inorgchem.9b00177  
  • Bhand, S., Landem D.N., Pereira, E., Gejji, S.P., Weyhermüller, T., Chakravarty, D., Puranik, V.G., Salunke-Gawali, S. (2019). Amphiphilic polypyridyl ruthenium complexes: Synthesis, Characterization and Aggregation studies Polyhedron 164, 96-107. https://doi.org/10.1016/j.poly.2019.02.035
  • Römelt, C., Weyhermüller, T., Wieghardt, K. (2019). Structural characteristics of redox-active pyridine-1,6-diimine complexes: Electronic structures and ligand oxidation levels Coordination Chemistry Reviews 380, 287-317. https://doi.org/10.1016/j.ccr.2018.09.018
  • Wang, M., Römelt, C., Weyhermüller, T., Wieghardt, K. (2019). Coordination Modes, Oxidation, and Protonation Levels of 2,6-Pyridinediimine and 2,2′:6′,2′́-Terpyridine Ligands in New Complexes of Cobalt, Zirconium, and Ruthenium. An Experimental and Density Functional Theory Computational Study Inorganic Chemistry 58(1), 121-132. https://doi.org/10.1021/acs.inorgchem.8b01949
  • Erken, C., Kaithal, A., Sen, S., Weyhermüller, T., Hölscher, M., Werlé, C., Leitner, W. (2018). Manganese-catalyzed hydroboration of carbon dioxide and other challenging carbonyl groups Nature Communications 9, 4521. https://doi.org/10.1038/s41467-018-06831-9
  • Kundu, S., Dutta, D., Maity, S., Weyhermüller, T., Ghosh, P. (2018). Proton-Coupled Oxidation of a Diarylamine: Amido and Aminyl Radical Complexes of Ruthenium(II) Inorganic Chemistry 57(19), 11948-11960. https://doi.org/10.1021/acs.inorgchem.8b01401
  • Levin, N., Codesido N.O., Marcolongo, J.P., Alborés, Weyhermüller, T., Olabe, J.A., Slep, L.D. (2018). Remarkable Changes of the Acidity of Bound Nitroxyl (HNO) in the [Ru(Me3[9]aneN3)(L2)(NO)]n+ Family (n = 1-3). Systematic Structural and Chemical Exploration and Bioinorganic Chemistry Implications Inorganic Chemistry 57(19), 12270-12281. https://doi.org/10.1021/acs.inorgchem.8b01958
  • Hahn, A.W., Van Kuiken, B.E., Chilkuri, V.G., Levin, N., Bill, E., Weyhermüller, T., Nicolaou, A., Miyawaki, J., Harada, Y., DeBeer, S. (2018). Probing the Valence Electronic Structure of Low-Spin Ferrous and Ferric Complexes Using 2p3d Resonant Inelastic X ray Scattering (RIXS) Inorganic Chemistry 57(37), 11918-11923. https://doi.org/10.1021/acs.inorgchem.8b01550
  • Van Kuiken, B.E., Hahn, A.W., Nayyar, B., Schiewer, C.E., Lee, S.C., Meyer, F., Weyhermüller, T., Nicolaou, A., Cui, Y-T., Miyawaki, J., Hatada, Y., DeBeer, S. (2018). Electronic Spectra of Iron-Sulfur Complexes Measured by 2p3d RIXS Spectroscopy Inorganic Chemistry 57(12), 7355-7361. https://doi.org/10.1021/acs.inorgchem.8b01010
  • Römelt, C., Ye, S., Bill, E., Weyhermüller, T., van Gastel, M., Neese, F. (2018). Electronic Structure and Spin Multiplicity of Iron Tetraphenylporphyrins in their Reduced States as Determined by a Combination of Resonance Raman Spectroscopy and Quantum Chemistry Inorganic Chemistry 57(4), 2141-2148. doi.org/10.1021/acs.inorgchem.7b03018
  • Rees, J.A., Bjornsson, R., Kowalska, J.K., Lima, F.A., Schlesier, J., Sippel, D., Weyhermüller, T., Einsle, O., Kovacs, J.A., DeBeer, S. (2017). Comparative electronic structures of nitrogenase FeMoco and FeVco Dalton Transactions 46(8), 2445-2455. https://doi.org/10.1039/c7dt00128b
  • Suturina, E.A., Nehrkorn, J., Zadrozny, J.M., Liu, J., Atanasov, M., Weyhermüller, T., Maganas, D., Hill, S., Schnegg, A., Bill, E., Long, J.R., Neese, F. (2017). Magneto-Structural Correlations in Pseudotetrahedral Forms of the [Co(SPh)4]2- Complex Probed by Magnetometry, MCD Spectroscopy, Advanced EPR Techniques, and ab Initio Electronic Structure Calculations Inorganic Chemistry 56(5), 3102-3118. https://doi.org/10.1021/acs.inorgchem.7b00097
  • Chowdhury, A.R., Roy, B.G., Jana, S., Weyhermüller, T., Banerjee, P. (2017). A simple cleft shaped hydrazine-functionalized colorimetric new Schiff base chemoreceptor for selective detection of F- in organic solvent through PET signaling: Development of a chemoreceptor based sensor kit for detection of fluoride Sensors and Actuators B: Chemical 241, 706-715. https://doi.org/10.1016/j.snb.2016.10.095
  • Römelt, C., Song, J.S., Tarrago, M., Rees, J.A., van Gastel, M., Weyhermüller, T., DeBeer, S., Bill, E., Neese, F., Ye, S. (2017). Electronic Structure of a Formal Iron(0),Porphyrin Complex Relevant to CO2 Reduction Inorganic Chemistry 56(8), 4745-4750. https://doi.org/10.1021/acs.inorgchem.7b00401
  • Manikandamathavan V.M., Thangaraj M., Weyhermüller T., Parameswari R.P., Punitha V., Murthy N.N., Nair B.U. (2017). Novel mononuclear Cu(II) terpyridine complexes: Impact of fused ring thiophene and thiazole head groups towards DNA/BSA interaction, cleavage and antiproliferative activity on HepG2 and triple negative CAL-51 cell line European Journal of Medicinal Chemistry 135(28), 434-446. https://doi.org/10.1016/j.ejmech.2017.04.030
  • Sabenya, G., Lázaro, L., Gambo, I., Martin-Diaconescu, V., Andris, E., Weyhermüller, T., Neese, F., Roithova, J., Bill, E., Lloret-Fillol, J., Costas, M. (2017). Generation, Spectroscopic, and Chemical Characterization of an Octahedral Iron(V)-Nitrido Species with a Neutral Ligand Platform Journal of the American Chemical Society 139(27), 9168-9177. https://doi.org/10.1021/jacs.7b00429
  • Hahn, A.W., Van Kuiken, B.E., al Samarai, M., Atanasov, M., Weyhermüller, T., Cui, Y.T., Miyawaki, J., Harada, Y., Nicolaou, A., DeBeer, S. (2017). Measurement of the Ligand Field Spectra of Ferrous and Ferric Iron Chlorides Using 2p3d RIXS Inorganic Chemistry 56(14), 8203-8211. https://doi.org/10.1021/acs.inorgchem.7b00940
  • Kowalska, J.K., Nayyar, B., Rees, J.A., Schiewer, C.E., Lee, S.C., Kovacs, J.A., Meyer, F., Weyhermüller, T., Otero, E., DeBeer, S. (2017). Iron L2,3-edge X-ray Absorption and X-ray Magnetic Circular Dichroism Studies of Molecular Iron Complexes with Relevance to the FeMoco and FeVco Active Sites of Nitrogenase Inorganic Chemistry 56(14), 8147-8158. https://doi.org/10.1021/acs.inorgchem.7b00852
  • Khannam, M., Weyhermüller, T., Goswami, U., Mukherjee, C. (2017). A highly stable L-alanine-based mono(aquated) Mn(II) complex as a T1-weighted MRI contrast agent Dalton Transactions 46(31), 10426-10432. https://doi.org/10.1039/c7dt02282d
  • Shit, M., Bera, S., Maity, S., Weyhermüller, T., Ghosh, P. (2017). Coordination of o-benzosemiquinonate, o-iminobenzosemiquinonate and aldimine anion radicals to oxidovanadium(IV) New Journal of Chemistry 41, 4564-4572. https://doi.org/10.1039/c7nj00186j
  • Levin, N. Perdoménico, J., Bill, E., Weyhermüller, T., Slep, L.D. (2017). Pushing the photodelivery of nitric oxide to the visible: are {FeNO}7 complexes good candidates? Dalton Transactions 46(46), 16058-16064. https://doi.org/10.1039/c7dt03142d

Group Members

Lab staff

  • Fabian Otto
  • Lukas Schubert

Chemical synthesis, X-ray structure analysis

Small Molecular Model Systems to Learn About Electronic Structure and Function

Chemical activation of inert small molecules like CO2, CH4, N2 is a key problem in energy research. In the future, energy from renewable sources will be used on a big scale to transform these abundant materials to chemicals for industry and agriculture. Metal catalysts are needed to make such transformations energetically and chemically efficient and selective. We strongly believe that a deep understanding of mechanistic functionality and electronic structure of catalytic systems vastly supports the process of developing better catalysts. It is our approach to combine in-house spectroscopic methods (EPR, MCD, Mössbauer, Resonance Raman, X-Ray methods, etc.) with quantum theory to shine light on the chemical and electronic structure of catalytically active centers. The combination of spectroscopy and theory allows to interpret even very complicated spectroscopic data and to extract the desired chemical information.

Research in my group focuses on the synthesis of small molecular metal complexes for spectroscopic investigations. Directed variation of structural and electronic parameters in a series of compounds allows to systematically studying their spectroscopic response. Our samples are typically analyzed by standard methods (elemental analysis, IR, UV/vis, NMR, XRD) before they are further investigated as mentioned above. Such compounds with known molecular structure provide a reliable basis to collect high quality spectroscopic data. In the following, two examples of recent projects are given.

Attempts to Model the Interstitial Carbon Atom in Nitrogenase

Nitrogenase is a bacterial enzyme which catalyzes the conversion of nitrogen from air to ammonia, an essential source for the biosynthesis of nitrogen containing compounds like peptides or nucleobases. The activation of nitrogen is very challenging since it is probably the most inert small molecule one could think of. We have learned a lot about the chemistry and structure of nitrogenase but the exact electronic structure, the catalytic mechanism and the function of an interstitial carbon atom[1] in the molybdenum cofactor remains extremely challenging.

One of the two metal containing cofactors in nitrogenase, namely FeMoco, has been identified to be the active site of the enzyme where nitrogen binds and ammonia is released. It is basically composed of seven iron-, a molybdenum-center, nine sulfides, and a central carbide ion (see structure I in Figure 1).

After we have recently worked on model complexes of FeMoco to shine light on the oxidation state of the Mo ion in the resting state[2] we started a project to synthesize iron clusters with bridging carbon ligands to model the central carbon atom in FeMoco. Very few examples of such complexes have been reported in literature and synthetic strategies allowing the introduction of C-based ligands bonded to more than one Fe atom (μ2-6-C-based ligands) are very rare, explaining the lack of suitable model systems.

We felt that ylides could be suitable ligands to build up carbon bridged complexes and investigated the reaction of ylides with Fe(II) diamido species [Fe(N(SiMe3)2)2] which, in a first step, formed mononuclear higly reactive three coordinate iron(II) complexes[3a] of type A or more general E (Figure 1).

Further experiments showed that E can undergo a self-protolysis reaction at elevated temperatures since a carbon bound proton of the ylid is in close proximity to a strong base L which allows formation of doubly yldiide-bridged diiron(II) complexes of type F and HL.

Complexes 1 and 2 represent the first examples of dinuclear ylid-supported Fe2C2 iron diamond cores (Figure 2). Fe-C-Fe angles are found to be very acute at about 78.5° and the Fe…Fe distances are very short at ~2.58 Å. Mössbauer and x-ray absorption spectra in combination with magnetic susceptibility studies showed that the complexes are strongly antiferromagnetically coupled high-spin iron(II) dimers. Density functional calculations (DFT) reproduce the experimental data well and exclude a direct metal-metal bond.

We are continuing this project with sulfur containing ligands of a similar type which better model the sulfur-carbon ligation environment of the iron centers in FeMoco and have successfully isolated diiron complexes containing a distorted tetrahedral C2S2 environment and trigonal bipyramidal C2S2N coordination shell. All full spectroscopic characterization and DFT study is on the way.[3b]

X-Ray Structure Determination

In close collaboration with the x-ray diffraction facility of the MPI für Kohlenforschung, my group provides service for the x-ray determination of compounds produced in the MPI CEC. Research on molecular transition metal compounds for catalysis or spectroscopic investigations heavily relies on single crystal structure determinations since self-assembly often dominates in coordination chemistry and directed synthesis to obtain target compounds is in many cases limited. X-ray structure analysis delivers highly precise information about the three-dimensional arrangement of atoms, thereby providing bond length and bond angles, which are of enormous importance in understanding chemical properties. Since it is our aim to correlate experimental features and functional properties with structure, X-ray structure analysis is vital to this area of research.

As an example, Figure 3 displays two crystal structures from a recent paper of the department of Molecular Catalysis (Prof. Leitner) in which a precatalyst 1 forms a reaction intermediate 2 upon addition of pinacol borane in KOtBu/THF solution.[4] The system is highly active and catalyses the reductive hydroboration of various aliphatic and aromatic carboxylic acids and even CO2.


[1] a) Lancaster, K. M.; Roemelt, M.; Ettenhuber, P.; Hu, Y.; Ribbe, M. W.; Neese, F.; Bergmann, U.; DeBeer, S., X-ray Emission Spectroscopy Evidences a Central Carbon in the Nitrogenase Iron-Molybdenum Cofactor. Science 2011, 334 (6058), 974.
b) Spatzal, T.; Aksoyoglu, M.; Zhang, L.; Andrade, S. L. A.; Schleicher, E.; Weber, S.; Rees, D. C.; Einsle, O., Evidence for Interstitial Carbon in Nitrogenase FeMo Cofactor. Science 2011, 334 (6058), 940-940.

[2] a) R. Bjornsson, F.A. Lima, T. Weyhermüller, P. Glatzel, T. Spatzal, O. Einsle, E. Bill, F. Neese, S. DeBeer: Identification of a spin-coupled Mo(III) in the Nitrogenase Iron-Molybdenum Cofactor. Chem. Sci. 2014, 5, 3096-3103.
b) R. Bjornsson, M.U. Delgado-Jaime, F.A. Lima, D. Sippel, J. Schlesier, T. Weyhermüller, O. Einsle, F. Neese, S. DeBeer: Mo L-Edge Spectra of MoFe Nitrogenase. Z. Anorg. Allg. Chem. 2015, 65-71

[3] a) S. Yogendra, T. Weyhermüller, A.W. Hahn, S. DeBeer: From Ylides to Doubly Yldiide-Bridged Iron(II) High Spin Dimers via Self-Protolysis. Inorg. Chem. 2019 ,58, 9358-9367
b) manuscript in preparation

[4] A. Kaithal, S. Sen, C. Erken, T. Weyhermüller, M. Hölscher, C. Werlé, W. Leitner: Manganese-Catalysed Hydroboration of Carboxylic Acids, Carbonates, and Carbon Dioxide. Nature Communications 2018, 9, Art. 4521; DOI: 10.1038/s41467-018-06831-9