SPECIAL ISSUE PREFACE pubs.acs.org/JPCA
Autobiography of Jan Peter Toennies
M
y father and mother both grew up in pre World War I Germany. At the age of 18 my father was drafted into the German army. After four years in a French prison camp he completed his Ph.D. studies as an organic chemist under Otto Diels (Nobel prize in Chemistry 1950). In 1925 he immigrated to the U.S. thereby escaping the chaotic conditions in post-war Germany. Since German Ph.D.s were in great demand, he had no problem obtaining a position with the Texaco Refining Co. in Bayonne, New Jersey. His fiancee, Dita Jebens, came soon after, and only after their marriage in Ellis Island was she allowed to enter the country. When I was born on May 3, 1930, my parents had moved to Philadelphia and my father had a job as a biochemist in a small inchoate cancer research group (one of the first in the world) attached to Lankenau Hospital in downtown Philadelphia. I grew up in the comfortable main line suburb Narberth. A big event in my youth was a 1937 trip to Germany to visit my grandparents in Husum in Northern Germany. I vividly remember the unfamiliar quaint brick houses, cobblestone streets and, especially, the pageantry, with banner carrying Hitler youth drummers marching through town. I was the center of attraction of my grandparents and aunts and uncles and will never forget the afternoon high tea with delicious pastries in the beautiful garden behind my grandfather’s “Gasthaus”. On returning home on the same ship that had taken me to Germany, I recall my frustration in communicating with the same boys that had been playmates coming over. I had forgotten how to speak English. This visit as an impressionable seven year old made me proud of my German heritage. In 1939 my brother Ralf Gerrit, who later became a chemical engineer, was born and in 1942 we moved to the rural Gladwyne suburb of Philadelphia into a new house with a large garden. There I could pursue many hobbies, including building electromotors and steam engine driven boats, which I could test behind our house on a pond that I had created with a large concrete dam. My father had tried to interest me in chemistry. Much to his disappointment, I never got beyond making nitrogen triiodide, which fascinated me because of the chainlike reaction leading to many little spontaneous explosions. I was a better-than-average student at Lower Merion public high school, which then was one of the best high schools in the country. In 1948 I was fortunate to be admitted to Amherst College with a small scholarship. My father was able to only pay half of my college expenses, so I had to work summers. My first job was on a farm in Vermont where I learned how to milk cows, drive tractors, harvest trees, and bring in the hay. Two summers were spent on oil tankers going between the Sun Oil Co. refineries in Marcus Hook, PA, and oil ports in Louisiana and Texas. I served on deck, where I stood long night watches on the bow, cleaned the latrines, or worked in the 100 °F engine room as a wiper. Despite some hardship, I enjoyed all of this as a great adventure, which also opened my eyes to the hard life of blue collar workers. Later I worked in the research lab of the Sun Oil Co., where I ran a Raney Nickel catalyzed hydrogenation apparatus, or for the r 2011 American Chemical Society
Penn Salt Co. (now Pennwalt). During my second year at Amherst, I worked as much as 40 h a week next to my studies to finance a summer trip to Germany. I worked at a print shop sweeping floors, delivering print jobs, proof reading, soliciting ads, and also in the student cafeteria. In the summer of 1950, I biked from Z€urich to Husum, visiting relatives along the way. I was shocked to see the burned out cities and widespread destruction, but fortunately all my close German relatives had survived the war without harm. At Amherst, I had little idea what to major in until in my sophomore year I attended a physical chemistry course given by David C. Grahame. Grahame was a dedicated and gifted teacher who also was a highly successful research scientist. His carefully organized clear lectures awakened my interest in understanding the molecular basis of chemical phenomena and convinced me to major in physics, with a senior course in physical chemistry. My senior honors project on microwave spectroscopy of the paramagnetic salt CuSO4 3 5H2O was supervised by William M. Fairbank. Soon afterward, Fairbank left Amherst and later moved to Stanford, where he became famous for many spectacular fundamental physics experiments. Both Grahame and Fairbank, although very different personalities, were inspiring mentors and certainly had a big effect on alerting me to the intellectual rewards of thinking about how molecules affect macroscopic phenomena. After receiving my BA in 1952, it was not easy for me to find the right graduate school. I had not had enough physics courses and my mathematical prowess was not considered sufficient for a first-rate graduate school in physics. Since I had managed to avoid taking a course in organic chemistry, I was also not prepared for graduate studies in chemistry. Fortunately, Brown University in nearby Providence, Rhode Island, accepted me for their graduate program in physical chemistry. In their new graduate program, beginning graduate students started on their research immediately on arrival instead of after several years of courses and successfully passing prelim exams. I became the first graduate student of Edward (Ned) F. Greene, who had arrived a few years earlier after a Ph.D. with the renowned George Kistiakowsky at Harvard. Ned’s modest, yet creative, pragmatic, and inventive, approach to science and life set an excellent example, which guided me from then on. My project was to build a shock tube with the aim to establish which one of several spectroscopically allowed values of the dissociation energies of N2 and CO were the correct values. At the very high temperatures (≈ 5000 K) behind the shock front, both gases, despite their high dissociation energies, were fully dissociated and thus they had a measurable effect on the shock wave velocity, which was measured optically with a rotating drum camera. Fortunately, in my dissertation I arrived at the presently accepted values of 9.76 and 11.1 eV, respectively. During my first year at Brown I somewhat impetuously applied for a Fulbright Scholarship to spend a year in Germany, Special Issue: J. Peter Toennies Festschrift Published: June 23, 2011 6742
dx.doi.org/10.1021/jp201144y | J. Phys. Chem. A 2011, 115, 6742–6745
The Journal of Physical Chemistry A not expecting that I would be accepted, but I was, and my next year was spent in Germany as a member of the first group of Fulbright exchange students to come to Germany after the war. I chose G€ ottingen as my university, where I was cordially received by the newly appointed Professor of Physical Chemistry, Wilhelm Jost. Despite my lack of experience and despite my full red beard (beards were by no means popular in these days), he accepted me and suggested a project using a new high speed drum camera to study spinning detonations in CO/O2 mixtures. The Fulbright Commission provided me with a monthly stipend of $100, the equivalent of DM 400, a large sum for students in those days. Thus, I could afford a Volkswagen beetle, which was the only other car in the Institute next to that of Prof. Jost. I fully enjoyed student life in the old university town of G€ottingen, which had been spared significant war damage, and occasionally attended lectures by Richard Becker, Werner B€uckel, Rudolph Hilsch, Werner Heisenberg, and Carl Friedrich von Weizs€acker. In the laboratory, I developed a novel way to study detonations as they propagate through glass tubes. Traditionally, the films in drum cameras were allowed to rotate normal to the direction of propagation of the detonation. It occurred to me that by arranging the optics so that the film would move parallel with the detonation front at the same speed it would be possible to “freeze out” the motion. With this new technique we could resolve a long-standing issue concerning the nature of spinning detonations. After my departure, my colleague and friend Heinz Georg Wagner wrote the article that is my first publication.1 Back at Brown, I attended the courses given by John Ross on statistical mechanics, Eugene Carpenter on quantum chemistry, and Robert Beyer on theoretical physics. In order to construct my shock tube apparatus I had to learn glass blowing, working with a lathe, and brazing, skills that proved to be very useful later in my career. In the final year of my graduate studies, I coauthored with Ned Greene the first book on chemical reactions in shock waves, which appeared in 1959 in German2 and as an enlarged edition in English in 1964.3 The 1955 paper by Ellison Taylor and Sheldon Datz at Oak Ridge entitled “Study of Chemical Reactions with Molecular Beams: The Reaction of K with HBr”4 and the excitement it created with Ned Greene and John Ross inspired me to look for a postdoctoral position to learn about molecular beams. I was fascinated by the basic directness, simplicity, and elegance of the molecular beam method for studying chemical dynamics. In 1957, the year of my Ph.D., with the exception of the Oak Ridge group, molecular beam research was only being pursued at a few physics laboratories largely in the U.S. and Germany. On a chance visit to Princeton, I was fortunate to meet Hans Gerhard Bennewitz who was on a sabbatical from Wolfgang Paul’s Institute in Bonn. Bennewitz liked my ideas to study molecular collisions by exploiting some of the techniques developed in Bonn and ultimately convinced Prof. Paul to invite me to come to Bonn. I accepted despite the small stipend and uncertain future in comparison to several lucrative U.S. job offers in industry. In hindsight, I suppose my quest for adventure had not yet been stilled by my tanker experiences and previous trips to Germany. The Physikalisches Institut in Bonn was an exciting place to be. Paul, who had arrived from G€ottingen in 1952, had started the construction of a 500 meV electron strong focusing electron synchrotron, the first accelerator in post World War II Germany. In addition to molecular beam studies of hyperfine interactions, a multitude of other research lines were being pursued: plasma physics, development of new particle detectors or new sources of
SPECIAL ISSUE PREFACE
polarized electrons, and, especially, mass spectroscopy using the high frequency quadrupole mass filter that Paul had invented a few years earlier and for which he later received the Noble Prize in 1989. Paul was a congenial and jovial person who would often stop me in the hallway to tell me a joke or story. One of his sayings, when I complained about our shop and other delays, was “Manchmal hilft warten” (Sometimes it helps to wait). Even though he was not versed in gas kinetics and chemical reactions, Paul enthusiastically supported my ideas to study inelastic collisions of molecules with rotational quantum state selection and analysis using electrostatic quadrupole fields. I worked closely with Bennewitz who was a master in experimental technology and taught me many experimental tricks and skills. Our idea was inspired by the Rabi arrangement of a state selector, microwave, or RF resonator region, followed by another state selector that served to analyze the transmitted beam for a radio frequency induced transition before it arrived at the detector. In our arrangement, the RF resonator was replaced by a secondary beam to collisionally excite the molecules (Figure 1). Our first experiment took 4 years of very hard work and tedious effort. Only after introducing single particle counting detection, which we learned from the accelerator group, were we able to measure the very small effects. Later we realized that we had been the first to introduce this technology to molecular beam experiments. In 1961, after our successes, Paul offered me a position as a salaried “Assistent”. I hesitated because I had planned to finally return to the U.S. After being unable to find a position in the U.S. that would enable me to continue these new experiments, I accepted his offer. As an “Assistant” I could set up my own group, which I had to support by writing proposals to the Deutsche Forschungsgemeinschaft (DFG). Then, in 1965, after Paul had given his explicit approval and encouragement, I applied for “habilitation” to obtain the “venia legendi” (the authorization and obligation to teach at a German university) in experimental physics. My first teaching assignment was a course in solid state physics, since it had never been offered there previously. This was quite a challenge because I myself had not had a course in solid state physics during my own studies. With a semipermanent position I felt that I could take on the responsibility of establishing a family. On August 30, 1966, my fiancee Monika Zelesnick and I got married. Monika had just passed her first state examination entitling her to teach mathematics and physics under supervision at a German “Gymnasium” (a school of higher education leading to the university). After two years of practice teaching, she became an “Assessor des Lehramts”, meaning that she was a fully accredited teacher. Our daughters, Susanne and Annette, born in 1969 and 1972, are now a medical doctor and a school teacher. We are blessed with five grandchildren. In the fall of 1968, I accepted an invitation to give a course on molecular beam chemistry at the University of Illinois. While I was in Urbana, the department indicated that they were interested in offering me a position in the Chemistry Department. On my return to Germany, however, I received a letter from the president of the Max Planck Society, Adolf Butenandt (Noble Prize in Chemistry in 1939), offering me a position as a scientific member of the Max Planck Society and director at the “MaxPlanck-Institut f€ur Str€omungsforschung” in G€ottingen. This Institute had been founded in 1925 by Ludwig Prandtl for fundamental studies of fluid dynamical phenomena. In the late 1960s, the Max Planck Society decided, following the initiative of Manfred Eigen (Nobel Prize in Chemistry in 1967), to augment the research program with investigations of the basic microscopic 6743
dx.doi.org/10.1021/jp201144y |J. Phys. Chem. A 2011, 115, 6742–6745
The Journal of Physical Chemistry A
SPECIAL ISSUE PREFACE
Figure 2. Aerial view of the Max Planck Institut f€ur Str€omungsforschung about 1990. The three four story buildings in the left foreground are the guest houses. Figure 1. Schematic diagram of the apparatus used to measure rotational quantum state-to-state inelastic collisions of polar molecules with other atoms or molecules.5
collision phenomena involved in fluid and gas dynamics. I also had an offer of a professorship in chemistry at the Technical University of Darmstadt, but Paul assured me that I should not pass up the opportunity to join the Max Planck Society. Thus, I accepted the offer and started my new position on January 1, 1969. Shortly after arriving in G€ottingen, I applied to the physics “Fachbereich” (faculty) at the University to have my “venia legendi” transferred to G€ottingen. Thus, finally at the age of 39, my meandering trajectory between the U.S. and Germany and between physics and chemistry came to an end and I settled down to become a physicist in Germany. By then I had realized that the greatest adventures were to be experienced in doing experimental research. The Max Planck Society is a truly wonderful Institution. It took me some time to get accustomed to not having to worry about funding and adjust to having the onerous lab work done by technicians and the availability of nearly unlimited shop time. My hard earned practical laboratory experience gained at Brown and Bonn came in good stead. Early on, the shop foreman patiently tried to explain to me, the new director, why our preposterous specifications could certainly not be met. I replied that I would gladly show him how the work could be done. After one visit to the shop, all problems seem to disappear and our technicians and machinists developed rapidly to make our shop one of the best in the world. The smooth operation of the institute, which, in addition to our group, consisted essentially of the molecular beams group of Hans Pauly, who came with me from Bonn, and a group continuing the fluid dynamics research of the former Institute, was supervised by a highly motivated, versatile, and extremely capable laboratory manager, Wolfgang Sattler. In addition to the generous funding for equipment, the financing of postdoctoral positions and short-term visitors was not encumbered with unnecessary bureaucracy. Since the Institute grounds included three guest houses with several large apartments and many single rooms, providing accommodations for guests was also no problem (Figure 2). The location of the Institute, in walking distance to the center of the old walled town, made it attractive for our numerous scientific visitors.
During the first six years I was somewhat puzzled by the realization that we were entirely free to do what ever we wanted and that there was no apparent external evaluation of our research. Funding was negotiated each year on the basis of the previous year. Then in 1975 the Max Planck Society introduced Advisory Boards, the members of which were appointed following the suggestions of the Institute. They were authorized to report back to the President of the Society and to advise him not only on the quality of the research but also on the possible needs or improvements. Thanks in large part to this Board we were able to continually modernize our shops and increase the staff. Since our Institute was located across the street from the Physics Institutes of the University, it was relatively convenient for students to join our research groups to do their “Diplom” (equivalent to a masters degree) or their Ph.D. research. This was usually reluctantly tolerated by the colleagues at the University, who were understandably concerned that they would lose their best students. Later, in the 1980s and early 1990s, however, it was welcomed, because the inflow of students was greater than the University’s capacity. This steady influx of good students was a great boon to our research. Until my official retirement in 1998, the permanent staff consisted of Christoph Ottinger, Ekkehard Hulpke, and Manfred Faubel, each of whom had their own research programs. Many of the projects were directed on a day-by-day basis by senior graduate students or visitors, some of whom would visit several months each year over a period of years. Notable among these long-term visitors were Michael Baer, Giorgio Benedek, Virginio (Bibi) Bortolani, Bruce Doak, Franco Gianturco, Zdenek Herman, Eldon Knuth, Dick Manson, David Micha, Salvador Miret Artes, Jan Northby, Carl Nyland, Lev Rusin, Boris Sartakov, Jim Skofronick, K. T. Tang, Helmut Weiss, and several others. As I have narrated in some detail elsewhere,6 the students and many young colleagues and several visitors played an important role in bringing our research forward and, in some instances, in even opening up new fields of research. Upon retirement in 1998, it was no longer possible for me to accept new research students from the University. Fortunately, my Russian colleagues were kind enough to send me Oleg Kornilov and Anton Kalinin to perform their research under my guidance for their Ph.D. degrees in Russia. With their help and several postdocs and guests, we were able to continue 6744
dx.doi.org/10.1021/jp201144y |J. Phys. Chem. A 2011, 115, 6742–6745
The Journal of Physical Chemistry A
SPECIAL ISSUE PREFACE
operating three apparatus up to 2005. The new directors Stephan Herminghaus and Eberhard Bodenschatz, who joined the Institute in 2003, have kindly made it possible for me to continue to use my office and support a part-time secretary and an undergraduate student. Presently, we are collaborating with Giorgio Benedek (Milano), Eldon Knuth (UCLA), Joe Chaiken and Jerry Goodisman (Syracuse University), David Ceperley (Urbana), Jesus Navarro (Valencia), Andrej Vilesov (Los Angeles, U.S.A.), and Victor Lebedev, Pyotr Moroshkin, and Antoine Weis (Fribourg), completing manuscripts describing pre-2005 experiments or analyzing new experiments or theoretical calculations. I very much welcome this occasion to thank the Max Planck Society for the complete freedom to choose our research directions and the nonbureaucratic generous support. Also, I want to thank the many guests and the institutions that supported them, especially the Alexander von Humboldt Foundation, the Max Planck Society, and the Deutscher Akademischer Austauschdienst (DAAD). The visitors kindly and openly shared with us their ideas and thereby provided much of the theoretical support and were a major factor in providing the interpretation of our experiments. Without the above support and, above all, without the dedicated hard work and youthfully inspired original ideas of the many students who ran the apparatus, and for the many guests who guided and advised them, we would not have been able to take full advantage of the opportunities made available to us. J. Peter Toennies
’ REFERENCES (1) Toennies, J. P.; Wagner, H. G. Photographische Untersuchungen an spinnenden Kohlendioxyd-Sauerstoff-Detonationen. Z. Elektrochem. 1955, 59, 7. (2) Chemische Reaktionen in Stosswellen; Greene, E. F., Toennies, J. P., Jost, W., Eds.; Fortschritte der Physikalischen Chemie; Steinkopf Verlag: Darmstadt, 1959; 202 pages. (3) Greene, E. F.; Toennies, J. P. Chemical Reactions in Shock Waves; Edward Arnold: London, 1964. (4) Taylor, E.; Datz, S. Study of Chemical Reaction Mechanisms with Molecular Beams: The Reaction of K with HBr. J. Chem. Phys. 1955, 23, 1711–1718. (5) Toennies, J. P. Molekularstrahlmessungen von Stossquerschnit:: ten f€ur Uberg€ange zwischen definierten Rotationszust€anden zweiatomiger Molek€ule, I Experimentelle Methode. Z. Phys. 1965, 182, 257– 277. (6) Toennies, J. P. Serendipitous Meanderings and Adventures with Molecular Beams. Annu. Rev. Phys. Chem. 2004, 55, 1–33.
6745
dx.doi.org/10.1021/jp201144y |J. Phys. Chem. A 2011, 115, 6742–6745
