During my undergraduate years, I’ve been working on ligands capable of coordinating specific metals. This included a little bit of synthetic work, analysis of the structure (with NMR and XRD) and analysis of thermodynamic properties (using potentiometric, UV-Vis and NMR titrations). My interest in the coordination chemistry led me to the inorganic chemistry studies and I acquired a detailed knowledge (and a degree as a byproduct) about organometallic compounds, coordination compounds and means to study such species.
Interest in the theoretical chemistry struck me during an NMR course, where I also met my Ph.D. supervisor for the very first time. I had two main topics at that time – a synthesis of ligands designed for metals such as aluminum and gallium and a theoretical prediction of the chemical bonding between heavy elements inside the fullerene cages. After finishing the experimental work, I left the practical chemistry and became a full-time theoretician.
Nowadays, I’m trying to connect the best of both worlds and use my knowledge of the coordination chemistry together with my ability to predict structures and properties computationally. Very recently, I dwelled into the world of teaching and want to use my knowledge and skills to find new ways of teaching chemistry attractively.
Heavy element bonding
Some of the heavy elements, such as actinides, are quite inaccessible to experimental studies due to their instability. Nevertheless, since we’ve seen bizarrely (from the point of view of your usual everyday carbon-based chemistry) bonding transition metals, such as two chromium atoms connected with quintuple bonds, there may be even more bizarre bonding between two actinides. And there is! In my research related to this, I’ve studied early actinides enclosed various fullerene cages. The cage is kind of a nanolaboratory to study these heavy fellas in and I’m not waving hands here – two uranium atoms and also two thorium atoms forming a chemical bond between each other have been experimentally enclosed in fullerenes. My take on the prediction of properties of such systems on a DFT level can be seen here.
But (there is always a but, isn’t there) while experiments can give us a structure of such species and also some properties, bonding mainly remains in the domain of theoretical chemists. And since we’re talking about really heavy elements with many nucleons and electrons, the theory has its issues and limitations (such as relativistic effects or inaccessibility of ab-initio based methods). My main topic as of now is to not only give us an idea of how strong the bonding between enclosed actinides really is but also what methods are appropriate to evaluate that. Stay tuned!
Properties of coordination compounds
As I have stated above, I didn’t really leave the field of the coordination chemistry. Merging the hands-on experience with a capability of calculating interesting things proved to be useful in either explaining some properties of complex compounds or predicting their geometry and properties. A collaboration with my former group yielded an article about simple, yet complex, uhm, complex. A collaboration with another group interested in coordination chemistry led to a study of macrocycle-based ligands designed to host lanthanides. During my time at the Los Alamos National Laboratory, I also collaborated with the experimentalists on complexes that could help us store an electrical energy. Besides these projects, I also use the simplest Werner-like complexes to create useful models for coordination chemistry lectures.
Fullerene-based molecular electronics
Enclosing things into the fullerene cages is fun, so why not move them around with an electric field, right? Yeah, we did that too, although just theoretically. While endohedral fullerenes are not accessible in great amounts and their use in electronics is thus far-fetched, in principle it works. Moreover, systems studied in our group seem to have very specific properties. Imagine a diode and a switch in a single molecule. Boom. You got a memristor, mentioned in the article above. After thorough investigation of the fullerene memristor, we investigated also a component capable of spin-filtering and coined it a spinristor.
Abovementioned systems led us to a general study of what diatomic molecule is the best to enclose from both the experimental view and the functionality of the system as an electronic component. Besides that, an experimental evidence shows that almost no transition metals can be enclosed in the cages using the state of art methods such as an arc discharge and a laser ablation. I’m looking into that as well.
List of publications
(9) Unraveling Actinide-Actinide Bonding in Fullerene Cages: A DFT versus Ab Initio Methodological Study
(8) Spinristor: A Spin-Filtering Memristor
(7) A Quest for Ideal Electric Field-Driven MX@C70 Endohedral Fullerene Memristors: Which MX Fits the Best?
(6) Hydrazine Energy Storage: Displacing N2H4 from the Metal Coordination Sphere
(5) Al(III)-NTA-fluoride: a simple model system for Al–F binding with interesting thermodynamics
(4) From π Bonds without σ Bonds to the Longest Metal–Metal Bond Ever: A Survey on Actinide–Actinide Bonding in Fullerenes
(3) Fullerene-Based Switching Molecular Diodes Controlled by Oriented External Electric Fields
(2) How Does a Container Affect Acidity of its Content: Charge-Depletion Bonding Inside Fullerenes
(1) Complexes of phosphonate and phosphinate derivatives of dipicolylamine
2023 - Poster - ICQC, Bratislava, Slovakia
2023 - Contributed talk - MMQC, Mariapfarr, Austria
2022 - Poster - European summerschool in quantum chemistry, Palermo, Italy
2019 - Poster - Theoretical inorganic chemistry winter school, Helsinki, Finland
2019 - Poster - Nanocon, Brno, Czech Republic
2019 - Poster - Transition metals and spectroscopy summer school, Gelsenkirchen, Germany
2019 - Poster - CECAM 50, Lausanne, Switzerland
2019 - Contributed talk - MMQC, Mariapfarr, Austria
2018 - Poster - Modern wavefunction methods summer school, Gelsenkirchen, Germany
2018 - Poster - MMQC, Mariapfarr, Austria
2023 - Jean-Marie Lehn prize (3rd place)
2021 - 2022 - Fulbright-Masaryk scholarship - Research of hydrazine binding in lanthanide complexes, LANL, USA
2019 - 2020 - Grant Agency of Charles University student grant - Research of endohedral fullerenes, CU, Czech Republic