A Conversation with Frans C. De Schryver
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books by Calver and Pitts, and this got me interested in the field also with the idea that this, in view of the presence of photographic industry in Antwerp, could help me in starting an industrial career upon returning back to Belgium. Things turned out differently, as I was asked to set up a new research group at K.U. Leuven, and at that time we focused on photochemistry related to polymer science. In an effort to develop photopolymerization systems in which each propagation step was photoinduced, we synthesized bichromophoric systems and found that not only an inter- but also an intramolecular reaction was possible, e.g., in N,N′-alkylbismaleimides. Mechanistic studies led us then to move more from photochemistry to photophysics in an area that then was booming: (intra)molecular excimer and exciplex formation, energy transfer, and electron transfer. This brought us in contact with great chemists and physicists such as Förster, Weller, Birks, Mataga, Porter, Turro, and Hammond, just to mention a few of those who made many seminal contributions and laid the foundations of present photosciences. At the end of the eighties through a summer stay at the IBM Laboratory at Almaden, contacts with the group of Prof. Urs Wild (ETH) and the participation in the research board of Prof. Hiroshi Masuhara’s Erato project “Microphotoconversion”, it became clear to me and my co-workers at the time that spatial resolution was the next important step forward. We started to invest in optical microscopy. In 1993 after a Humboldt stay in MPI Mainz with Prof. Gerard Wegner and Jürgen Rabe, who just returned from Almaden and had made the first STM images of organic molecules on graphite, we set up a research program “Scaling down in time and space” going from picosecond time resolution to femtosecond spectroscopy with Marc van der Auweraer, installing scanning probe microscopy with Steven De Feyter and together with Johan Hofkens, who had acquired optics expertise during a post doc with Prof. Masuhara in Osaka, Japan and the late Prof. Paul Barbara, at that time still at the University of Minnesota, Minneapolis carrying out single-molecule spectroscopy. EL: You have been one of the early pioneers in single-molecule spectroscopy and developing other f luorescence techniques. Could you please share some of the challenges you encountered during the early years? De Schryver: The most difficult thing was to convince funding agencies when you move from a known territory to less familiar ground that they should fund your proposal. While originally categorized as an organic polymer chemistry laboratory, the research moved more and more toward photophysically oriented projects for which sophisticated lasers were required. The funding agencies considered laserbased spectroscopy to be the playground of physicists, not of synthetic (polymer)chemists. It took a while before we got the
rof. De Schryver is well-known for his seminal contributions to photoscience and fluorescence spectroscopy. In particular, his contributions in the area of photoinduced energy transfer in polymers and other multichromophoric systems have laid the foundations for the design of light-harvesting assemblies. His research has focused on fundamental aspects of photochemistry and photophysics and their use in the study of physicochemical properties of complex systems. During the last 20 years, he contributed primarily to the emerging field of time- and space-resolved (photo)chemistry and nanoscience including scanning probe microscopy, optical microscopy, and single-molecule spectroscopy. He is currently a Professor Emeritus at K.U. Leuven in the Department of Chemistry. Many researchers with whom he worked together in his laboratory are now leading spectroscopists. During the recent MAF 2017 (The 15th Conference on Methods and Applications in Fluorescence) held in Bruges, Belgium, we had the opportunity to meet with Prof. De Schryver and discuss the progress made in the area of photochemistry (Figure 1).
Figure 1. Frans C. De Schryver (R) and Prashant Kamat (L) at MAF 2017 in Bruges, Belgium. (Photo courtesy of Vincent Van den Dries.)
EL (ACS Energy Letters): Your contributions to photochemistry are well-recognized. How did you become interested in these research topics early in your career? De Schryver: Originally I was, as an undergraduate student, trained as a physical chemist and decided after my then obligatory military service to do a Ph.D. in polymer chemistry. At the end of the doctoral degree my then promotor, Georges Smets, enticed me to do a postdoctoral, something I would strongly encourage all young scientists to do, and I went as a Fulbright student to work with Speed Marvel, one of the godfathers of polymer chemistry and a leading American polymer chemist who just had moved to Tucson. During my stay in Arizona, I got a copy of one of the first photochemistry © XXXX American Chemical Society
Received: December 18, 2017 Accepted: December 18, 2017 191
DOI: 10.1021/acsenergylett.7b01289 ACS Energy Lett. 2018, 3, 191−192
Energy Focus
Cite This: ACS Energy Lett. 2018, 3, 191−192
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money. With this in mind we, with some help from industrial sponsors, when we shifted to time- and space-resolved topics, financed ourselves the first STM and optical microscope and proved first that our idea of using such equipment in organic chemistry was valid, and we applied, only then, for funding. Very important in this was the successful application for European money, at that time through ESF, which led to a long-lasting and very fruitful collaboration with, among others, the Müllen group. EL: The photochemistry that started with simple molecular systems has now expanded to various disciplines, f rom biology to material science, f rom diagnostics to photodynamic therapy, and f rom solar cells to display devices. What new strategies do you foresee in adapting photochemistry to address emerging scientific challenges? De Schryver: It has been a joy to see how, thanks to an explosion of the technical potential of many aspects of the equipment and the fundamental endeavors of many young scientists, the field of imaging and photonics has grown and is now an integral part of life and material science. The borders between chemistry, physics, and biochemistry have vanished. The future certainly will see even more extensive development of correlative microscopy and spectroscopy techniques leading to combination of three-dimensional nanometer-resolved images with high time resolution. In all of these developments, fundamental knowledge of photosciences will remain a key determining factor. Only when the fundamental aspects of photophysics are mastered can lasting impact be made. A nice example is the development of STED microscopy. Stimulated emission is a fundamental aspect of a molecule’s photophysics. In solution, this concept has been explored in the development of dye-based lasers. Stefan Hell then extended the concept to microscopy, and the impact of this idea has changed the whole field of optical imaging. EL: Today, a large number of students obtain Ph.D. degrees in photochemistry and spectroscopy. What is your advice to these young researchers on how to be successful in their careers? De Schryver: To our students I would first of all say: Try to get as solid and as broad a base as possible; make sure you read critically the literature also outside your own research area or topic; talk to and have discussions with visiting scientists; go and participate actively in symposia and do a post doc in a field adjacent to yours; look at where emerging areas of interest are and grab opportunities. See, for example, the perovskite field. Perovskites are an old material and represented a small research field for a long time. When it was shown that it could be used as an active medium in dye-sensitized solar cells, Snaith, Park, and others picked it up, and see where the field is standing now! But most of all, enjoy doing solid and honest science where the pleasure of an original idea experimentally proven strongly compensates many unsuccessful attempts and nights spent in the laboratory.
Views expressed in this Energy Focus are those of the authors and not necessarily the views of the ACS. The authors declare no competing financial interest. Biography
Prof. Frans C. De Schryver obtained his Ph.D. degree from K.U. Leuven in 1964. After carrying out postdoctoral research at University of Arizona, he joined K.U. Leuven as an Assistant Professor in 1969. He became full professor in 1975 and maintained an active research career garnering international recognitions. He has led several research panels in Europe and served on advisory boards of scientific journals. He is currently serving as Professor Emeritus in the Department of Chemistry at K.U. Leuven. He has published over 600 papers in peer-reviewed journals. He was a visiting professor in many universities and held appointments as a long-time scientific associate at The Université Catholique de Louvain. He is a member of the Koninklijke Vlaamse Academie van België voor Wetenschappen en Kunsten and was president of the Klasse van de Natuurwetenschappen (2002). He received the following awards: Fulbright Research Fellowship in 1964, was a Laureate of Koninklijke Academie voor Wetenschappen van België, a Senior Research Awardee of the Alexander von Humboldt Foundation in 1993, recipient of the Chaire Bruylants in 1994. He was a Porter Medalist, awarded jointly by the European, Inter-American, and Japanese Photochemical Societies, and a recipient of a Francqui Chair in 1998. He received the Havinga Medal and was holder of the Förster Memorial Lecturer in 1999. He was further awarded the Frontiers in Biochemistry Award in 2000, the Max-Planck-Forschungspreis für Chemie in 2001, the International Award of the Japanese Photochemical Society, the special medal of The University of Groningen in 2005, and the Blaise Pascal medal in 2007. (Photo courtesy of Suzy Bosteels.)
Johan Hofkens
K.U. Leuven, Heverlee 3001, Belgium
Prashant V. Kamat, Editor-in-Chief
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University of Notre Dame, Notre Dame, Indiana 46556, United States
AUTHOR INFORMATION
ORCID
Johan Hofkens: 0000-0002-9101-0567 Prashant V. Kamat: 0000-0002-2465-6819 192
DOI: 10.1021/acsenergylett.7b01289 ACS Energy Lett. 2018, 3, 191−192
