Dr. Dimitrios Manganas - Advanced experimental and theoretical spectroscopy

Dr. Dimitrios Manganas
Leiter der Gruppe Advanced experimental and theoretical spectroscopy
Abteilung Molekulare Theorie und Spektroskopie

Vita

Diplom (Chemie)University of Athens, Griechenland (2002)
M.Sc. (Chemie)University of Athens, Griechenland (2004)
PhD (Chemie)University of Athens, Griechenland (2007)
PostdocUniversität Bonn (2007-2009)
Postdoc MPI für Bioanorganische Chemie; heute: MPI CEC  (2011-2013)
Gruppenleiter
MPI CEC (seit 2014)

Publikationen

Selected publications

  • Kubas, A., Berger, D., Oberhofer, H., Maganas, D., Reuter, K., Neese, F., Surface Adsorption Energetics Studied with “Gold Standard” Wave-Function-Based Ab Initio Methods: Small-Molecule Binding to TiO2(110). J. Phys. Chem. Let., 7, 4207-4212, (2016).
  • Maganas, D., Trunschke, A., Schlogl, R., Neese, F., A unified view on heterogeneous and homogeneous catalysts through a combination of spectroscopy and quantum chemistry. Faraday Discussions, 188, 181-197, (2016).
  • Van Kuiken, B. E., Hahn, A. W., Maganas, D., DeBeer, S., Measuring Spin-Allowed and Spin-Forbidden d–d Excitations in Vanadium Complexes with 2p3d Resonant Inelastic X-ray Scattering. Inorg. Chem., 55, 11497-11501, (2016).
  • Atanasov, M., Aravena, D., Suturina, E., Bill, E., Maganas, D., Neese, F., First principles approach to the electronic structure, magnetic anisotropy and spin relaxation in mononuclear 3d-transition metal single molecule magnets. Coord. Chem. Rev., 289, 177-214, (2015).
  • Jiang, S. D., Maganas, D., Levesanos, N., Ferentinos, E., Haas, S., Thirunavukkuarasu, K., Krzystek, J., Dressel, M., Bogani, L., Neese, F., Kyritsis, P., Direct Observation of Very Large Zero-Field Splitting in a Tetrahedral (NiSe4) Coordination Complex. J. Am. Chem. Soc., 137, 12923-12928, (2015).
  • Suturina, E. A., Maganas, D., Bill, E., Atanasov, M., Neese, F., Magneto-Structural Correlations in a Series of Pseudotetrahedral [CoII(XR)4]2- Single Molecule Magnets: An ab Initio Ligand Field Study. Inorg. Chem, 54, 9948-9961, (2015).
  • Maganas, D., Roemelt, M., Weyhermuller, T., Blume, R., Havecker, M., Knop-Gericke, A., DeBeer, S., Schlögl, R., Neese, F., L-edge X-ray absorption study of mononuclear vanadium complexes and spectral predictions using a restricted open shell configuration interaction ansatz. Phys. Chem. Chem. Phys., 16, 264-76, (2014).
  • A combined DFT and restricted open-shell configuration interaction    method including spin-orbit coupling: Application to transition metal L-edge X-ray absorption spectroscopy. M. Roemelt, D. Maganas, S. DeBeer and F. Neese, J. Chem. Phys., 138, 204101 (2013).
  • Maganas, D., Roemelt, M., Havecker, M., Trunschke, A., Knop-Gericke, A., Schlögl, R., Neese, F., First principles calculations of the structure and V L-edge X-ray absorption spectra of V2O5 using local pair natural orbital coupled cluster theory and spin-orbit coupled configuration interaction approaches. Phys. Chem. Chem. Phys., 15, 7260-76, (2013).
  • Theoretical Analysis of the Spin Hamiltonian Parameters in CoIIS4      Complexes, Using Density Functional Theory and Correlated ab initio Methods. D. Maganas,  S., Sottini, P., Kyritsis and F. Neese., Inorg. Chem., 50   8741-8 (2011).  

Full publicationslist

Full publications list on Researcher ID

Preise

  • HPC-EUROPA scholarship for research stay (University of Barcelona, 2007)
  • Marie Curie researcher fellowship  (University of Leiden, 2004-2006)

Gruppenmitglieder

Postdocs

  • Dr. Agisilaos Chantzis

Advanced Experimental and Theoretical Spectroscopy

Research in the Manganas group focuses on the development and application of advanced experimental and theoretical spectroscopic methodologies for the study of heterogeneous catalytic reactions.

Identifying catalytically active structures or intermediates in homogeneous and heterogeneous catalysis is a formidable challenge. It is well known that even for industrially leading catalytic processes there is a limited understanding regarding the catalytic activity of the working catalysts as well as the catalytic intermediates involved in the catalysis mechanisms. Such ‘missing’ information is however essential for the design of new functional materials. With all these in mind we have developed a joint project between several groups and departments in the institute aiming a spectroscopic and a reactivity understanding of the materials science processes.

 

 

 

Theoretical X-ray spectroscopy

With the aim to uniquely correlate spectroscopic property to electronic structure and geometric property, we are working closely with the groups of Mossbauer & MCD  (Dr. Eckhard Bill) and X-Ray spectroscopy (Prof. Dr. Serena DeBeer) as well as with the heterogeneous reactions department (Prof. Dr. Robert Schlögl) and operate over the entire spectroscopic energy scale in order to evaluate unique spectroscopic signatures of transition metal complexes and materials in both equilibrium  and under operando conditions.

This requires to use methods that do not belong in the  stanard arsenal of quantum chemistry. As an example we have recently shown that the DFT Restricted Open-Shell Configuration Interaction with Singles (ROCIS) method[1] can succesfully treat the metal L-edge problem on classes of molecular systems from transition metal compounds up to polymetallic clusters with several 100s of atoms.1 In this respect we have explored this methodology to treat the metal L-edge problem on various close and open shell compounds and polymetallic clusters.[2-4]

Theoretical spectroscopic protocols for catalysis

An important activity in the group is to develop valid spectroscopic protocols that are able to treat relevant problems that are met in the fields of homogeneous and heterogeneous catalysis. The ultimate goal here is to develop a spectroscopic information content that is transferable between the homogeneous and heterogeneous catalysis worlds.

As an example we have recently employed a combination of spectroscopic methods to study two closely related systems from the heterogeneous (the silica-supported vanadium oxide VOx/SBA-15) and homogeneous (the complex K[VO(O2)Hheida]) domains.[5] The results of the study demonstrate that: a) a combination of several spectroscopic techniques is of paramount importance in identifying signature structural motifs and b) quantum chemistry is an extremely powerful guide in cross connecting theory and experiment as well as the homogeneous and heterogeneous catalysis fields. It is emphasized that the calculation of spectroscopic observables provides an excellent way for the critical experimental validation of the theoretical results.

Accurate energetics for solid systems

As in addition to spectroscopy, reactivity plays an essential role in understanding the structure and the properties of catalytic active centers, in close collaboration with the experimental groups at MPI-CEC, the group shows activity in defining protocols that can deliver accurate energetics in problems similar to those met in solid state catalysis. In a characteristic example it has been recently shown that using the domain-based pair natural orbital local correlation concept (DLPNO-CCSD(T)), allows for ab initio calculations provide reference adsorption energetics at solid surfaces with an accuracy approaching 1 kcal/mol and at affordable computational cost.[6]

References

[1] Roemelt M., Neese, F., Excited states of large open-shell molecules: an efficient, general, and spin-adapted approach based on a restricted open-shell ground state wave function. J Phys. Chem. A. 117, 3069, (2013).  

[2] Maganas, D., Roemelt, M., Weyhermuller, T., Blume, R., Havecker, M., Knop-Gericke, A., DeBeer, S., Schlögl, R., Neese, F., L-edge X-ray absorption study of mononuclear vanadium complexes and spectral predictions using a restricted open shell configuration interaction ansatz. Phys. Chem. Chem. Phys., 16, 264-76, (2014).  

[3] Roemelt M, Maganas D, DeBeer D and Neese F, A combined DFT and restricted open-shell configuration interaction    method including spin-orbit coupling: Application to transition metal L-edge X-ray absorption spectroscopy. J. Chem. Phys., 138, 204101 (2013).  

[4] Maganas, D., Roemelt, M., Havecker, M., Trunschke, A., Knop-Gericke, A., Schlögl, R., Neese, F., First principles calculations of the structure and V L-edge X-ray absorption spectra of V2O5 using local pair natural orbital coupled cluster theory and spin-orbit coupled configuration interaction approaches. Phys. Chem. Chem. Phys., 15, 7260-76, (2013).  

[5] Maganas, D., Trunschke, A., Schlogl, R., Neese, F., A unified view on heterogeneous and homogeneous catalysts through a combination of spectroscopy and quantum chemistry. Faraday Discussions,188, 181-197, (2016).  

[6] Kubas, A., Berger, D., Oberhofer, H., Maganas, D., Reuter, K., Neese, F., Surface Adsorption Energetics Studied with “Gold Standard” Wave-Function-Based Ab Initio Methods: Small-Molecul Binding to TiO2(110). J. Phys. Chem. Let., 7, 4207-4212, (2016).