Dr. Leon Freitag University of Vienna Institute of Theoretical Chemistry Währinger Str. 17 1090 Vienna Austria leon.freitag@univie.ac.at +43 1 4277 52762 |
Focus Area |
I am investigating the electronic ground state and excited state properties of large transition metal complexes, using density functional theory (DFT) and ab-initio multiconfigurational methods such as CASSCF/CASPT2. In particular, I am interested in ruthenium nitrosyl complexes, which are of potential use in anti-cancer photodynamical therapy, both in their ground state electronic structure, due to the non-innocency of the nitrosyl ligand, as well as in their excited state properties and the mechanism of photorelease of NO from these complexes. For the latter investigation, I also employ ab-initio surface hopping molecular dynamics. This work is carried out in close cooperation with the department of Inorganic Chemistry at the University of Vienna. |
Publications |
Simplified State Interaction for Matrix Product State Wave Functions J. Chem. Theor. Comput. 17, 7477-7485, (2021), DOI: 10.1021/acs.jctc.1c00674 L. Freitag, A. Baiardi, S. Knecht, L. González A Density Matrix Renormalization Group Study of the Low-Lying Excited States of a Molybdenum Carbonyl-Nitrosyl Complex Chem. Phys. Chem. 22, 2371-2377, (2021), DOI: 10.1002/cphc.202100549 15. L. Freitag, L. González The Role of Triplet States in the Photodissociation of a Platinum Azide Complex by a Density Matrix Renormalization Group Method J. Phys. Chem. Lett 12, 4876-4881, (2021), DOI: 10.1021/acs.jpclett.1c00829 14. M. Moerchen, L. Freitag, M. Reiher Tailored Coupled Cluster Theory in Varying Correlation Regimes J. Chem. Phys. 153, 244113, (2020), DOI: 10.1063/5.0032661 M. Moerchen, L. Freitag, M. Reiher OpenMolcas: From Source Code to Insight J. Chem. Theory Comput. 15, 5925-5964, (2019), DOI: 10.1021/acs.jctc.9b00532 I. F. Galván, M. Vacher, A. Alavi, C. Angeli, J. Autschbach, J. J. Bao, S. I. Bokarev, N. A. Bogdanov, R. K. Carlson, L. F. Chibotaru, J. Creutzberg, N. Dattani, M. G. Delcey, S. Dong, A. Dreuw, L. Freitag, L. M. Frutos, L. Gagliardi, F. Gendron, A. Giussani, L. González, G. Grell, M. Guo, C. E. Hoyer, M. Johansson, S. Keller, S. Knecht, G. Kovačević, E. Källman, G. Li Manni, M. Lundberg, Y. Ma, S. Mai, J. P. Malhado, P. Å. Malmqvist, P. Marquetand, S. A. Mewes, J. Norell, M. Olivucci, M. Oppel, Q. M. Phung, K. Pierloot, F. Plasser, M. Reiher, A. M. Sand, I. Schapiro, P. Sharma, C. J. Stein, L. K. Sørensen, D. G. Truhlar, M. Ugandi, L. Ungur, A. Valentini, S. Vancoillie, V. Veryazov, O. Weser, P.-O. Widmark, S. Wouters, J. P. Zobel, R. Lindh Shedding Light on the Nature of Photoinduced States Formed in a Hydrogen Generating Supramolecular RuPt Photocatalyst by Ultrafast Spectroscopy J. Phys. Chem. A 122, 6396-6406, (2018), DOI: 10.1021/acs.jpca.8b00916 11. A. Atkins, F. Talotta,L. Freitag, M. Boggio-Pasqua, L. González Assessing Excited State Energy Gaps with Time-Dependent Density Functional Theory on Ru(II) Complexes J. Chem. Theory Comput. 13, 4123-4145, (2017), DOI: 10.1021/acs.jctc.7b00379 10. P. S. Kuhn, S. M. Meier, K. K. Jovanović, I. Sandler, L. Freitag, G. Novitchi, L. González, S. Radulović, V. B. Arion Ruthenium-Carbonyl Complexes with Azole Heterocycles: Synthesis, X-ray Diffraction Structures, DFT Calculations, Solution Behavior and Antiproliferative Activity Eur. J. Inorg. Chem. 2016, 1566-1576, (2016), DOI: 10.1002/ejic.201501393 9. Q. Pan, L. Freitag, T. Kowacs, J. C. Falgenhauer, J. P. Korterik, D.Schlettwein, W. R. Browne, M. T. Pryce, S. Rau, L. González, J. G. Vos, A. Huijser Peripheral Ligands as Electron Storage Reservoirs and their Role in Enhancement of Photocatalytic Hydrogen Generation Chem. Comm. 52, 9371-9374, (2016), DOI: 10.1039/C6CC05222C 8. M. Jäger, L. Freitag, L. González Using Computational Chemistry to Design Ru Photosensitizers with Directional Charge Transfer Coord. Chem. Rev. 304, 146-165, (2015), DOI: 10.1016/j.ccr.2015.03.019 7. L. Freitag, S. Knecht, S. F. Keller, M. G. Delcey, F. Aquilante, T. B. Pedersen, R. Lindh, M. Reiher, L. González Orbital Entanglement and CASSCF Analysis of the Ru-NO Bond in a Ruthenium Nitrosyl Complex Phys. Chem. Chem. Phys. 17, 14383-14392, (2015), DOI: 10.1039/C4CP05278A L. Freitag, S. Knecht, S. F. Keller, M. G. Delcey, F. Aquilante, T. B. Pedersen, R. Lindh, M. Reiher, L. González Analytical Gradients of Complete Active Space Self-Consistent Field Energies Using Cholesky Decomposition: Geometry Optimization and Spin-State Energetics of a Ruthenium Nitrosyl Complex J. Chem. Phys. 140, 174103, (2014), DOI: 10.1063/1.4873349 5. L. Freitag, L. González Theoretical Spectroscopy and Photodynamics of a Ruthenium Nitrosyl Complex Inorg. Chem. 53, 6415-6426, (2014), DOI: 10.1021/ic500283y 4. P. Kuhn, A. Gavriluta, G.E. Büchel, V.B. Arion, L. Freitag, L. González, G. Novitchi, J. Tommasino, E. Jeanneau, D. Luneau Mechanism Elucidation of the Cis-Trans Isomerization of an Azole Journal of Biological Inorganic Chemistry 19, S612, (2014), DOI: 10.1007/s00775-014-1095-8 3. A. Gavriluta, G. Büchel, L. Freitag, G. Novitchi, J.-B. Tommasino, E. Jeanneau, P.-S. Kuhn, L. González, V. Arion, D. Luneau Mechanism Elucidation of the Cis-Trans Isomerization of an Azole Ruthenium-Nitrosyl Complex and its Osmium Counterpart Inorg. Chem. 52, 6260-6272, (2013), DOI: 10.1021/ic4004824 2. E. J. F. Dickinson, L. Freitag, R. G. Compton Dynamic Theory of Liquid Junction Potentials J. Phys. Chem. 114, 187-197, (2010), DOI: 10.1021/jp908024s |