Vincenzo Balzani, Emeritus Professor, University of Bologna, Italy, is one of the most cited chemists worldwide. Here he talks to Dr. Martin Preuss for ChemViews Magazine about photochemistry, the responsibility of scientists to share their knowledge, and his secrets of success.
Professor Balzani, you are one of the most-cited chemists in the world. Do you want to share the secret of your successful career with our readers?
First, I have a passion for scientific research and delight in discovering the beauty of chemistry step by step. I also had the invaluable privilege of working in a group made of highly motivated, reliable, and friendly colleagues and co-workers. Most of the praise for my achievements goes to them.
Particularly important, of course, have also been, year after year, the exchange of ideas and profitable collaborations with outstanding scientists all over the world: Franco Scandola, Alex von Zelewsky, Jean-Marie Lehn, Sebastiano Campagna, Jean-Pierre Sauvage, Fernando Pina, Fritz Voegtle, Fraser Stoddart, and several others. Such collaborations have allowed us to achieve results that would have been otherwise impossible to achieve and, no less important, have created a network of friendships that have made our work much more pleasant and amenable.
You are well known for your work on photochemistry. How did you become interested in this field?
It was by chance or, if you wish, serendipity. When I was a student in my second year of the Chemistry course at the University of Bologna, I began to attend the research laboratory of Professor Vittorio Carassiti. During that period, one of Carassiti’s colleagues was trying to obtain the Raman spectra of cyanide complexes of molybdenum and tungsten. He did not succeed, however, because those complexes underwent decomposition upon irradiation with the Raman excitation lamp. That photodecomposition intrigued Carassiti, who was working on ligand-substitution processes of metal complexes. He decided to begin a systematic investigation of the photochemical reactions of metal complexes, a field completely unexplored at that time, and asked me to start with experiments. I should add that in our department there was a long tradition in photochemistry, going back to the beginning of the last century when Giacomo Ciamician used to perform photochemical experiments on the roof of the building using the sun as a light source.
The scope of your research interests from photochemistry over supramolecular chemistry to nanotechnology is impressive. How do you manage to conduct high-level research on such a wide range of topics?
It was a natural progression from simple to more and more complex systems. After several years of studies on mononuclear metal complexes, we realized that binuclear or polynuclear metal complexes displayed very interesting intramolecular photoinduced energy and electron-transfer processes and we envisaged that light-induced processes in suitably designed supramolecular systems could be used to generate interesting functions. Of course, ideas are not sufficient in chemistry, and we were lucky to begin long-lasting and very profitable collaborations with several synthetic groups that provided us with the supramolecular systems we wanted to study. In a few years we conceived that the macroscopic concepts of a device or a machine could be extended to the molecular level, which means nanotechnology. Molecular devices and machines, like those of the macroscopic world, need energy to operate. Our photochemical background suggested to us that the most convenient energy source to make molecular machines work is light. Following this idea, we have constructed and investigated a variety of light-powered artificial molecular-level devices and machines. A further advantage offered by light is that, in addition to supplying energy, it can also be used to “read” the state of the system and thus to control and monitor its functions.
Do you remember how many PhD theses you have supervised and how many of your students pursued an academic career afterwards?
Including post-docs and young visiting fellows, I have supervised about 60 researchers from European and extra-European countries. Several of them are now full professors at universities or directors at research centers in Italy, France, Spain, Germany, Sweden, UK, Canada, and Brazil.
Some scientists seem to regard teaching as a burden. How do you personally view this part of a university professor’s work?
Teaching is a burden for those who have not yet understood that education is not filling a bucket, but lighting a fire, as stated by Greek philosophers. I like teaching because it is very rewarding to see students learning, and also because teaching is the best way to learn (Lucius Annaeus Seneca: Homines dum docent discunt). My experience is that students are much more interested in what you are saying if you show passion not only for your scientific research, but also for the human being.
What should we teach our students? Of course, to solve problems, to take care in planning experiments, to be open to sharing ideas and collaborating, to publish results that can be replicated, to write papers and proposals that are easy to read, to follow safety regulations, to be able to communicate. But we should also teach our students, or at least discuss with them, other no less important topics, such as being aware of the limitations of science and technology, to remember that science has to be guided by ethical values, to pay attention to the needs of society, and to become authoritative and concerned citizens.
This is also reflected in your textbooks that you have published over the years, the most recent one being Photochemistry and Photophysics: Concepts, Research, Applications.
Can you tell us a bit about the didactic approach you adopt in your teaching and your writing?
Writing a book and teaching are quite different activities, but some important rules must be used in both cases. First, one should have a clear plan in mind. Second, one should make every effort to explain his plan at the beginning, which can be done in an introductory lecture when teaching and in a clear content list in the case of a book. I hate books in which chapters are not subdivided into sections and subsections. I encourage students to underline terms and sentences in their books and I try to write books where important terms and sentences are in italics. I believe that most scientific concepts can be better illustrated by a clear diagram or figure than by many words. I believe that both in teaching and in writing a book one should always make reference as much as possible to what happens in the real world. Particularly in the case of young students, to see chemistry in action and have direct experience through appropriate experiments is certainly much more fascinating and stimulating than reading a textbook.
Do you have any advice for a student aspiring to become a scientist?
The first suggestion is: Choose the field you like most. If you do not like what you are doing, there is no hope of achieving useful and interesting results. A scientist has to plan experiments and to look at the results obtained with care and love. Only in this way can one succeed. As Szent-Gyorgyi said, “Discoveries consist in seeing what everybody has seen and thinking what nobody has thought”. If you love what you are doing, you will never say that you are working hard and you will be able to think what nobody has thought.
In addition to your academic teaching activities, you are engaged in educating the public and decision-makers on the importance of science for the solution of some of mankind’s most pressing problems, such as the energy issue. How do you do this, and how is the feedback?
To live in the third millennium, we need new thinking and new ways of perceiving the world’s problems. Politicians should realize that the Earth is a spaceship with limited resources that carries 7 billion people. Excluding the light coming from the sun, Earth is a closed system. This simple consideration tells us that in the long run for energy we can only rely on solar energy. Apparently, neither politicians nor their economic advisors are acquainted with this unavoidable conclusion. Nor are they acquainted with the principle that unlimited economic growth on a finite planet is not possible. In affluent countries we live in societies where the concepts of “enough” and “too much” have been removed. Learning to say, “Enough”, however, is a necessary condition for a sustainable world, particularly from the viewpoint of energy consumption. We do not care as much as we should about underdeveloped countries; establishing equality, however, is not only a moral duty, but also a basic need for creating a peaceful world.
Scientists should clearly explain these concepts to all citizens and especially to economists and policy-makers. There is a great need to spread information about the actual condition of our world. Only knowledge can help us make the right decisions in order to reach sustainability and remedy disparities, so as to make our spaceship Earth less fragile during its trip through this new century.
Going back to energy, I believe that nuclear energy is not the right answer to fight inequality and to create a more peaceful world. We should reduce energy consumption and rely on renewable energies that are well distributed all over the world. We should intensify our efforts to exploit solar energy not only to obtain heat and electricity, but also to obtain fuels, for example, by photochemical water splitting, a process proposed by my group many years ago.
Thank you for the interview.
Vincenzo Balzani, born November 15, 1936 in Forlimpopoli, Italy, studied chemistry at the University of Bologna, Italy. In 1973, he became full professor at the “Giacomo Ciamician” Department of Chemistry at the same university. He has been visiting professor at several universities. From 1977 to 1988, he was the Director of the Photochemistry and Radiation Chemistry Institute of the National Research Council, Washington, DC, USA.
Balzani is a member of several academies, including the American Association for the Advancement of Science, the Royal Society of Chemistry (RSC), the European Academy of Sciences, and the Accademia Nazionale dei Lincei. He was chairman of the Gruppo Italiano di Fotochimica (1982–86) and of the European Photochemistry Association (1988–92), and he has been a member of the editorial board of several international journals, including Chemistry—A European Journal,ChemPhysChem, Small, and ChemSusChem.
His research interests cover a wide range of topics: photochemistry, photophysics, supramolecular chemistry, electron-transfer reactions, molecular-level devices and machines, nanotechnology, and photochemical solar-energy conversion. His scientific activity has been documented in more than 600 papers, mostly published in highly qualified journals, as well as eight monographs.
- Gold Medal “S. Cannizzaro”, Italian Chemical Society, 1988;
- Italgas European Prize for Research and Innovation, 1994;
- Prix Franco-Italien de la Société Française de Chimie, 2002;
- Quilico Gold Metal, Organic Division, Italian Chemical Society, 2008;
- Blaise Pascal Medal, European Academy of Sciences, 2009;
- Nature Award for Mentoring in Science Italy, 2013.
- Processing Energy and Signals by Molecular and Supramolecular Systems,
V. Balzani, A. Credi, M. Venturi,
Chem. Eur. J. 2008, 14, 26.
- Photochemical Conversion of Solar Energy,
V. Balzani, A. Credi, M. Venturi,
ChemSusChem 2008, 1, 26.
- Old Molecules, New Concepts: [Ru(bpy)3]2+ as a Molecular Encoder–Decoder,
P. Ceroni, G. Bergamini, V. Balzani,
Angew. Chem. Int. Ed. 2009, 48, 8516.
- Light-Powered Molecular Devices and Machines,
P. Ceroni, A. Credi, M. Venturi, V. Balzani,
Photochem. Photobiol. Sci. 2010, 9, 1561.
- The Hydrogen Issue,
N. Armaroli, V. Balzani,
ChemSusChem 2011, 4, 21.
- Molecular Devices and Machines: Concepts and Perspectives for the Nanoworld,
V. Balzani, A. Credi, M. Venturi,
Wiley-VCH, Weinheim, Germany, 2008 (translated in Chinese).
- Energy for a Sustainable World: From the Oil Age to a Sun-Powered Future,
N. Armaroli, V. Balzani,
Wiley-VCH, Weinheim, Germany, 2011.
- Powering Planet Earth: Energy Solutions for the Future,
N. Armaroli, V. Balzani, N. Serpone (Translator),
Wiley-VCH, Weinheim, Germany, 2013.
- Photochemistry and Photophysics: Concepts, Research, Applications,
V. Balzani, P. Ceroni, A. Juris,
Wiley-VCH, Weinheim, Germany, 2014.
- Reading and Writing the Book of Nature,
V. Balzani, M. Venturi, N. Serpone (Translator),
Royal Society of Chemistry, London, UK, 2014.