Special Issue Preface pubs.acs.org/JPCC
Autobiography of Ron Naaman
I
After graduation I decided to study at the Weizmann Institute. The 1973 war interfered, and I served seven months in it as a member of the reserve forces. After the war, I began my PhD under the supervision of Gad Fisher from Ben Gurion University and the late Mendel Cohen from the Weizmann Institute. My research was in high resolution spectroscopy of heterocyclic molecules. We took high resolution spectra and investigated the radiationless processes in these molecules. This type of work provided me with a solid background in molecular physics in general and in spectroscopy in particular. It has served me well in my career. The most significant step I took in my career was moving to Stanford to become a postdoctoral fellow with Richard (Dick) N. Zare. Dick was involved in various subjects of research, all related to laser spectroscopy. Being exposed to all these subjects under the fantastic mentoring of Dick was a defining experience. I found myself studying molecular spectroscopy, developing multiphoton ionization as a spectroscopic tool, and using a home-built excimer laser that my friend, Ziv Karny, built from scratch, to study the photodissociation of organometallics, and much more. Following these very fruitful two years at Stanford, I had to wait another year to get a position at the Weizmann Institute. Dick arranged for me to get a position with Dudley Herschbach at Harvard. The stay at Harvard, although relatively short, exposed me to excellent scientists and particularly to Dudley, from whom I learned a lot on how one should approach science. Dudley and Dick are both remarkable people who have a passion for science. I was lucky to meet and work with them in the early stages of my career. At the Weizmann Institute I started my research by studying reactions of van der Waals molecules. Dudley was generous enough to give me some equipment which enabled me to start my lab quickly, despite the small amount of setup money I received. I had to build a nitrogen laser and a dye laser by myself. With the help of great students and postdocs, I made progress in my research. The question I tried to answer was: How can weak interactions (like van der Waals forces) have a strong effect on the result of reactions occurring in cross molecular beams? Interesting effects could be found, and we investigated in detail reactions of oxygen atoms with various clusters. Later, when I spent a sabbatical at JILA, in Boulder, Colorado, I collaborated with Veronica Vaida and extended these studies to intracluster reactions. At the same time, I began collaborating with Zeev Vager, who developed the Coulomb Explosion Imaging technique, and together we studied the structure of clusters. In this project, negatively charged species are accelerated to several MeV, and then, using a laser, the electron is detached. The now neutral projectile passes through a few nm thick carbon foil, so that many of its electrons are stripped. As a result, the nuclei find themselves on a repulsive Coulomb potential and the cluster
n the early 1950′s, just after I was born, Israeli society consisted mainly of new immigrants, but I was an Israeliborn child to Israeli-born parents, quite a unique situation in those days. My childhood was characterized by constant movement, from one town to the next. I started elementary school in Beer-Sheva, a city surrounded by desert and inhabited by large communities of immigrants. There were immigrants from North Africa, the Middle East, and Eastern Europe. When school began, I was the only child in class whose mother tongue was Hebrew. In those days, in Beer-Sheva, there was an intense communal effort to build a modern new life in the newly established state of Israel. This spirit animated my teachers in elementary school, who were very dedicated and, despite the relatively poor conditions, made school an exciting place for us. It was then, at fourth grade in Beer-Sheva, that I was first exposed to hands-on science as I built a hot-air balloon. I could not believe my eyes: I made paper, which is heavier than air, fly. To me, this was a miracle. Two aspects of these childhood experiences in BeerSheva have persisted throughout my life: I have always been surrounded by people of different cultures and origins, and I have always had dedicated teachers. I feel this combination made me what I am today. When I was twelve years old my family moved to Munich, Germany, where my father was one of the first Israelis to get a fellowship on the basis of the newly formed German−Israeli relationships. The time in Germany had a deep influence on me. As a child in Israel, I heard of the horrible crimes of the Germans during World War II, and as I arrived to Munich, I expected to find people who are capable of committing such horrendous deeds. To my bewilderment, the people I met in Munich were like people everywhereboth good and bad, compassionate and cold, tender and crude. This suggested to me that people everywhere are in danger of behaving terribly if they “join the mob” and do not preserve their own sense of right and wrong. I studied in Maria Theresia Ober Real Schule and had great teachers who taught me science and sparked my interest in Physics and Chemistry. When I turned eighteen I was conscripted to the Israeli army for mandatory service, and I served for 3.5 years. As my combat military service drew to its end, I did not have the time or energy to go through a long application process to universities. The Ben Gurion University in Beer-Sheva just started a new faculty for Sciences and had a fairly straightforward application process. I was accepted to a unique program which tried to teach us “everything”namely, Mathematics, Physics, and Chemistryat a high level. The ambitious program was canceled after two years, but I was fortunate enough to get a very good basis in all three subjects. The faculty members were young and highly motivated, and, being a member of the first class ever in the program, I benefitted from their great efforts. These first couple of years led to my first research project, as an undergraduate, and to a job as an undergraduate teacher assistant. © 2013 American Chemical Society
Special Issue: Ron Naaman Festschrift Published: October 31, 2013 22173
dx.doi.org/10.1021/jp403786k | J. Phys. Chem. C 2013, 117, 22173−22174
The Journal of Physical Chemistry C
Special Issue Preface
established scientific and personal relationships despite the political differences. Throughout my scientific career I was lucky to collaborate with extraordinary individuals from all over the world, who became my close personal friends. We scientists are very fortunate to belong to an international community that has so much in common and involves so many good individuals. I would like to take this opportunity to thank all my professional−personal friends and to let them know that I cherish our relationships. Finally, I thank my wife, Rachel, my children and family for all the support they have provided and for their ability to keep up with my intense engagement in scientific research.
dissociates. A special detector detects each of the atomic ions and determines their energy in the center of mass of the exploded cluster. In addition, the charge of the ion is determined. As a result, it is possible to reconstruct the density function of the nuclei inside the cluster before it exploded. This is a method that provides molecular structure directly with no need to assume a Hamiltonian, as done in spectroscopy. Indeed, the technique is especially valuable in the case of floppy systems, for which many of the approximations used in common spectroscopy are not valid. Zeev and I thought (and still think) that the method is unique and provides information on molecular structure, not available from any other method. As is often the case when one introduces new methods, we faced also strong opposition, and I felt that only our strong friendship and mutual support made it possible for us to advance the experiments. At the time, there was a severe shortage in space at the Weizmann Institute, and I shared an office with Jacob Sagiv, who had just pioneered the study of self-assembled monolayers of silanes on oxides surfaces. We began collaborating on a new project in which we scattered atoms and molecules from surfaces covered with these monolayers. The results were exciting and, again, proved the importance of weak interactions in defining the outcome from scattering processes. A decade later, other groups began to perform similar experiments, and the subject is still a vibrant one. After scattering molecules from self-assembled monolayers, I continued to investigate photoelectron transmission through these layers. As in former studies, the new experimental method opened up an interesting field in physics/chemistry. But it was when we began to investigate the scattering of spin polarized electrons from monolayers made from chiral molecules that things turned really exciting. To our surprise we observed a significant spin dependent in this process. These studies, first published in 1999 together with Dave Waldeck, who spent a sabbatical at Weizmann, became the focus of my research and led us to what we call now the “Chiral Induced Spin Selectivity” (CISS) effect. A breakthrough in these studies was the result of a collaboration with the group of Helmut Zacharias in Münster, Germany, who were able to measure the actual spin polarization of electrons after being transmitted through chiral monolayers. This work, published in Science in 2011, invoked great interest in the subject. Currently, through collaboration with Dave Waldeck and Catalina Achim, from the University of Pittsburgh and Carnegie Mellon University, respectively, we are focusing efforts in probing the extent to which the CISS effect is responsible to the long distance electron transfer in Biology. We are lucky to have the theoretical support of another good friend and collaborator, David Beratan. In another collaboration with Yossi Paltiel, from the Hebrew University, we are developing spintronics devices that are based on the CISS effect. Alongside the research I conduct, I have been involved in the Department of Science Education at the Weizmann Institute. As scientists, we are obligated to contribute to scientific education at all levels. Motivating teachers by telling them of the scientific activity in our lab is very rewarding. My commitment to science education led to my involvement in the “Malta Conferences”, organized by Zafra Lehrman and aimed at bringing together scientists and science educators from all over the Middle East. In the last ten years, individualseducators and scientistsfrom all countries in our turbulent region have been meeting regularly. We have
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dx.doi.org/10.1021/jp403786k | J. Phys. Chem. C 2013, 117, 22173−22174
