Laudatio Prof. Dr. Mathias S. Wickleder

In 1985, Mathias Wickleder began studying chemistry at the University of Hannover and graduated with a thesis on ‘New investigations on ternary halides of rare earth elements with silver’. Without any delay this was followed by a PhD thesis in inorganic chemistry under the supervision of Prof. Dr. G. Meyer at the Institute of Inorganic Chemistry at the University of Hannover on the topic of ‘Complex halides of lanthanides with sodium and silver: synthesis, crystal structures, ionic conductivity’. During his time as a PhD student, he also studied history and philosophy. The latter obviously did not deter him too much from his obsession chemistry, as he successfully completed his dissertation on June 10th in 1994. Influenced by his work with Prof. G. Meyer during his diploma and PhD thesis, or simply because of his year of birth (atomic number 65 = Tb), he continued his work on rare earth compounds during his approximately 1.5-year postdoctoral stay with Prof. H. U. Güdel in Switzerland. By the time he conducted the research for his habilitation, during which Mathias Wickleder also devoted himself to rare earth compounds, he had become an independent expert in this field, for which he is still known and respected today. With the knowledge he had gained up to that point about the synthesis, characterisation and use of rare earth compounds in luminescence applications, he completed his habilitation in 2000 with a thesis on ‘Contributions to the crystal chemistry and thermal behaviour of compounds of rare earth elements with complex anions’ and received his venia legendi in the same year. Not mentioned so far, but certainly important, is his wife Prof. Dr. Claudia Wickleder, whom he met and fell in love with while studying at the University of Hanover. They went to Switzerland together to do their postdocs, and no doubt they had many scientific discussions about the chemistry of rare earth elements. From 2002–2015, Mathias Wickleder initially held a professorship for Inorganic Functional Materials at the University of Oldenburg on an interim basis and subsequently the position was offered to him permanently. This period was particularly formative for him. His chemistry shifted somewhat away from basic research towards a stronger application orientation (without losing sight of the fundamentals), but also somewhat away from rare earth elements towards others in the periodic table. Precious metals increasingly came into his focus and polysulfates started to fascinate him more and more. Particularly influential works date from the end of his habilitation and his time in Oldenburg. These include a publication on the synthesis and characterisation of gold(II) sulfate and a paper on octahedrally coordinated Pd(II) in Pd(S2O7). Today he is probably most famous for his research on sulfates, polysulfates and their respective derivatives. However, Mathias Wickleder is not only an outstanding scientist, but also an excellent teacher. The Teaching Prize at the University of Oldenburg in 2008 is one example representing the many years of enthusiastically lecturing the next generations of chemists. In addition to research and teaching, Mathias Wickleder has also been involved in university politics. He was active not only at the institute and faculty level, but also at the university level. The latter ultimately manifested itself in a period of approximately 1.5 years as Vice President for Studies, Teaching and Continuing Education at the Carl von Ossietzky University Oldenburg. Coordinating this demanding task with looking after his group has certainly been challenging, but it also reflects his strengths. Equipped with all these skills, he was appointed a W3 professor at the University of Gießen in 2015 and in 2017 he accepted a position as W3 professor at the University of Cologne, where he has been working until today. Mathias Wickleder is a very creative chemist and due to his enormously broad range of expertise he frequently comes up with unusual ideas to synthesize new solid-state compounds. His management style allows employees the freedom to develop, yet he is there when needed. His enthusiasm for chemistry spills over to the entire group when you talk to him about new results, and he is and has always been a great mentor at every stage of training. This is clearly reflected in the large number of graduates from his research group over the past years as professor. His unique way of granting freedom for research while still providing support for his employees is certainly also one of the reasons why three junior research groups settled with him and all of them succeeded to get to the next stage of their careers. We would like to thank Mathias Wickleder for his many exciting contributions to various topics in solid-state chemistry, some of which have found their way into inorganic chemistry textbooks. We thank him for his many fascinating anecdotes, his hard work for the university and our solid-state chemistry community, and of course we thank him for his many entertaining lectures at our joint conferences. Dear Mathias, we wish you many more exciting new structures, lots of fun with chemistry and, of course, good health together with your wife Claudia. We hope that you will continue to dance the valence vibrations of the polysulfates at our joint conferences for a long time to come! The laudators Maxim Bykov, Bertold Rasche and Jörn Bruns