HERSHBAH (Herschbach), Dudley R.( The American chemist, Nobel Prize in Chemistry, 1986)
Comments for HERSHBAH (Herschbach), Dudley R.
Biography HERSHBAH (Herschbach), Dudley R.
genus. June 18, 1932
American chemist Robert Dudley was born in Hershbah g. San Jose (Calif.) and was the eldest of six children of Robert Dudley Hershbaha, building contractor, and Dorothy Edith (nee Biir) Hershbah. While living in California in the countryside, X. been the instigators of mobile games, in sports. His successful performances in the national team's soccer team schools Campbell helped him win a scholarship to study and football at Stanford University, . where he played for the first year and was invited to try their hand at professional club 'Los Angeles Rams',
. Soon, however, enthusiasm for learning pushed sports on the second plan.
In the second year stay at Stanford X. began to conduct experiments on chemical kinetics, under the leadership of the American chemist Harold C. Johnston. While most experimental tests of the theory of the transition states of chemical reactions based on data obtained for complex chemical reactions. Johnston suggested X. measure the speed of simple chemical reactions, direct verification of this theory. In 1954, Mr.. H. received a bachelor's degree in mathematics, but with the same success could be qualified and chemistry, and physics. In 1955, Mr.. He received a Master of Science in Chemistry for his thesis, . chapters which were devoted to developing methods, . allowing more precise calculations pre-exponential factors for a series of simple reactions in testing the theory of the transition state,
. After graduation he continued his studies at Harvard, where he received in 1956. Master's degree Physical Sciences, and in 1958. - Ph.D. in chemical physics. His doctoral work he carried out jointly with the staff of the American chemist E. Bright Wilson, who subsequently developed new graceful techniques of microwave spectroscopy to study molecular structure and molecular barriers to internal rotation of. H. made a significant theoretical and experimental contributions by developing methods for calculating the energy levels of the intramolecular rotation and the rotation of entire molecules.
. He was the youngest member of the College Board, Harvard University (1957 ... 1959), Assistant Professor (1959 ... 1961), and then Associate Professor (1961 ... 1963) Chemistry, University of California at Berkeley
. In 1963, Mr.. he became professor of chemistry at Harvard University. At Harvard, he served as program manager for the Chemical Physics (1964 ... 1977), dean of the Department of Chemistry (1977 ... 1980), as well as a member of the faculty council (1980 ... 1983).
When in late 1959. H. moved to Berkeley, knowledge of the chemical levels remained at pre-war level. Quantum theory, which appeared in 1900, gave a more accurate picture of the structure of atoms and molecules and explains many aspects of the observed chemical processes. However, chemists are still very little known about the mixing of substances, control of temperature and pressure and the identification of reaction products. Theoretical models that had remained largely static, reactive molecules are considered as coexisting side by side, randomly colliding with one another and sometimes create a new regrouping. Still a student, X. interested in open one of his professors of molecular beams, the flux of molecules crossing the vacuum chamber, which recorded the change in energy. This method allowed him to more accurately monitor the individual molecules in the process of their interaction.
X. began to study the dynamics of molecular beams at Berkeley at a time when John K. Polanyi began to study chemical dynamics at the University of Toronto, using a different method, called hemilyuministsentsiey, which turned out to complement the method of X. A small group of undergraduate and graduate students, together with X. constructed a device in which two molecular beam crossed, with one beam of potassium atoms contained, and the other consisted of molecules of carbon, hydrogen and iodine. Details of the reaction after the intersection of these flows have been studied using devices called surface ionization detector. The ingredients beams was determined taking into account the fact that these compounds effectively react (this is proved even Michael Polanyi, the father of John K. Sexes), and the detector, according to other researchers, it is convenient for monitoring the reaction products in the experimental conditions. Already in the first experiments X. able to obtain detailed dynamics of productive molecular collisions and register the change in energy accompanying the formation of reaction products. This information allowed the group X. characterize the reaction mechanism (called rebound-mechanism) and find that in most cases, the release of chemical energy occurs in the form of vibrational energy, concentrated in the reaction products.
. Let considerable difficulties, but the experiments were conducted in more complex versions of substances of the same class
. These results are somewhat different from previous ones, as the reaction mechanism was different (so-called strippint-mechanism). Liberated energy to be more in the form of internal excitation of the molecules than in the form of kinetic energy. It was studied in many other reactions, especially after the X. in 1963. moved to Harvard, where he continued his work. His experiments covered a wide range of reactions, . including mixed and the reaction mechanism (with elements of both the above mechanisms), . and reaction, . proceeding with the formation and subsequent decay of long-lived complex in the synthesis of end products,
. The obtained data allowed to verify the statistical theories of chemical reactions and understand the important role of angular momentum.
. Despite advances in experiments with this class of substances, . as alkali (compounds, . that interact with acids to form salts), . further progress in the research required to improve equipment, . bring it to the universality,
. In 1967, carrying out post-doctoral studies at Harvard, X. started working with Ian Lee. With some students, Lee began to design and construct a new one 'supercar', . which were used to create the nipple supersonic beams, . moving mass spekgrometrichesky detector (which are variable electric and magnetic fields, . that leads to rejection of the products formed from the initial trajectory, depending on their properties, . so that they can collect and identify), . improved differential pump to create a deep vacuum, . and analysis program speed of the reaction products and computers for data storage,
. After making the entire apparatus for 10 months, Li, X. and their colleagues carried out a kind of revolution in this section science. Been studied, and with much greater accuracy, many reactions with more complex molecular composition. In one of the reactions involving hydrogen and chlorine, a group X. determine the distribution of angular velocity and rebound velocity for the compounds, the intramolecular vibrations which are identified John Polanyi using the method hemilyuministsentsii. The results of the two groups to study the dynamics of this reaction coincided even in the details. The results of this study X. in the eyes of colleagues brought innovator, generator of ideas, enthusiastic and inspired scientific thought.
In 1986. H. with Lee and Polanyi was awarded the Nobel Prize in chemistry for fundamental contributions to the development of a new field - the dynamics of chemical reactions, allowing a more detailed report of their process flow. Prior to this new work, all chemical reactions, researchers have largely considered the system volume and the average effect of many random molecular collisions, while the details of the collision escaped their attention. H. Compare this situation with baseball, where 'an entire dark pitcher starts the dark balls at the same darkness sports fields at the same time and where absolutely impossible to understand what is happening'. Studying the dynamics of reactions can simplify the game so that the observer can see to it 'as a pitcher, one runs the ball on the same field'.
In 1964, Mr.. H. married Georgina Lee Botios, also a chemist, assistant dean of Harvard College, they have two daughters. They enjoy an active lifestyle, they love chamber music and even played on stringed instruments, forming a family quartet. With a wide range of interests and the exigencies of sight, X. successfully engaged in teaching, enjoys great influence on his students and colleagues. Within five years he and his wife were co-heads the Club graduate of Harvard University, attracting many students and younger teachers to educational and social activities.
In addition to the Nobel Prize, X. awarded on the fundamental chemistry of the American Chemical Society (1965), . Medal Spiersa Faraday Society (1976), . medal to the 100 anniversary of the British Society of Chemistry (1977), . Linus Pauling Medal of the American Chemical Society (1978) and Irving Langmuir Prize in Chemical Physics of the American Physical Society (1983),
. He is a member of the U.S. National Academy of Sciences, the American Academy of Arts and Sciences, the American Physical Society and the American Association of Basic Sciences. He was awarded an honorary degree from the University of Toronto.