Lieselotte-Templeton-Prize 2024: Ben Ebel

Since 2022, the DGK awards the Lieselotte-Templeton-Prize for excellent bachelor’s or master’s theses. In 2024 one of the awardees was Ben Ebel. Congratulations!

Already during school, Ben was interested in the natural sciences and went for an internship at the University of Greifswald before deciding to study chemistry at RWTH Aachen. For his Master’s thesis on the topic of Ti(VI) coordination chemistry, he joined the group of Iris Oppel and after finishing his studies with excellence in 2023 he decided to stay there for a PhD project.



Could you give us a brief overview of your work?

My work consists of the characterization of different titanium(IV) based metal complexes and the ligand used for coordination in the solid state as well as in solution. I managed to recrystallize a ligand precursor and utilized quantumcrystallographic refinement through NoSpherA2 to gain deeper insight into a tautomerism between a catechol-imine and semiquinone-amine form which are both visible simultaneously within the crystal structure. Reduction of the compound lead to the ligand system which I subsequently used for coordination attempts. In-situ NMR and ESI-MS analysis showed the formation of two distinct complexes in solution which could both be selectively crystallized through variation of the strength and amount of base used for the deprotonation of the ligand. The first complex turned out to be a heterobimetallic Ti(IV)/Ca(II) complex and the second one the monometallic Ti(IV) complex with a chloride anion.


What was the biggest challenge you needed to overcome in your thesis?

By far the greatest challenge was the structure solution and modelling of the monometallic Ti(IV) complex, which posed several crystallographic challenges. The monoclinic unit cell with β=90.06(2)° led to the suggestion of higher symmetry, but the Laue class could be determined by the lack of symmetry visible in reciprocal space. However, modelling proved to be similarly challenging as the large amount of disorder due to the chloride anion and various DMSO solvent molecules present in the structure resulted in a very moderate diffraction power (~1 Å). The crystallographic model and the presence of the chloride anion were further substantiated by a chloride test using AgNO3 and EDX analysis.


What was your favourite part of this year’s DGK conference?

My favourite part was seeing all the people I had met at various other crystallographic meetings, such as the Garching Crystallography Workshop, as well as meeting many new people I had not had the chance to meet before. It is always amazing for me to see not only the wide range of chemical systems that are characterised by XRD, but more importantly the passion of all the people involved in the crystallographic discipline.