Swiss Scientist and professor Richard R. Ernst (born 1933) received the 1991 Nobel Prize in Chemistry for his pioneering work in the development of techniques for high-resolution nuclear magnetic resonance spectroscopy. Because of his work, nuclear magnetic resonance techniques became valuable tools in chemistry and also found application in other sciences.
The contributions of Nobel Prize-winning chemist Richard Robert Ernst proved far-ranging, as his work in the area of high-resolution nuclear magnetic resonance (NMR) spectroscopy led to the development of magnetic resonance imaging, which would become one of the most valuable non-invasive diagnostic imaging technologies available to medical professionals.
Ernst was born on August 14, 1933, in Winterthur, Switzerland, to Robert Ernst and Irma Brunner. Ernst later described his hometown as a place of both artistic and industrious activity, and this would influence both his recreational and career pursuits. At an early age, he learned how to play violincello and demonstrated an interest in musical composition. However, he also became fascinated with chemistry. This interest took hold when he was 13 years old. While exploring the family attic, he discovered a case filled with chemicals that had once belonged to his late uncle, who was a metallurgical engineer. Through this discovery, Ernst became intrigued by the possibilities of chemical reac-
Pursuing his fascination with chemistry, Ernst would later enroll at the Swiss Federal Institute of Technology (Eidgenössiche Technische Hochschule) in Zurich (ETH-Z). At the same time, he continued his own studies through outside reading. In particular, he cited Theoretical Chemistry by S. Glasstone as being very influential, as it revealed to him the fundamentals of quantum mechanics, spectroscopy, statistical mechanics, and statistical thermodynamics. These subjects weren't typically addressed in academic lectures, he would later point out.
At ETH-Z, he received his undergraduate degree in chemical engineering in 1956. He received his Ph.D. in physical chemistry in 1962, working on high-resolution NMR, a field that was then in its infancy.
After Ernst received his Ph.D., he wanted to leave the academic environment and find an industrial job in the United States. He moved to Palo Alto, California, where he took a position as a chemist at Varian Associates and sought practical applications of his research. Ernst had received numerous offers, but he chose Varian because the firm employed well-known scientists such as Weston A. Anderson, Ray Freeman, Jim Hyde, Martin Packard, and Harry Weaver. They were conducting lines of research similar to the ones Ernst had pursued in Zurich. Moreover, they were seeking commercial applications for their research, which attracted Ernst, as he felt it would provide further motivation for his own work.
While at Varian, Ernst worked with Anderson to make NMR spectroscopy more sensitive. They based their work in part on NMR experiments reported in 1945 by Felix Bloch at Stanford University and Edward Mills Purcell at Harvard. Bloch and Purcell had demonstrated that various atomic nuclei could be knocked out of alignment in a strong magnetic field when exposed to a slow sweep of radio frequencies. Further, these nuclei would respond by realigning to resonant frequencies and emit a signature similar to that of a chemical signature. This pioneering research garnered Bloch and Purcell Nobel Prizes.
Purcell foresaw NMR becoming a valuable tool for chemical analysis. However, before that prediction could become true, researchers needed to overcome the limited sensitivity of the early NMR method to the chemical signature of the substance being analyzed. Up to this point, only a few substances (including hyrdrogen, fluorine, and phosphorus) had spectra strong enough for consistent identification.
By 1966 Ernst and Anderson dramatically enhanced NMR spectra by replacing the problematic slow sweep of radio frequencies with short pulses of high intensity. As a result, spectra that was once too weak for identification was now clearly distinguishable. Computer advancements had made this possible. "Of major importance for the success of more advanced experiments and measurement techniques in NMR was the availability of small laboratory computers that could be hooked up directly to the spectrometer," Ernst said in 1991. "During my last years at Varian (1966–68), we developed numerous computer applications in spectroscopy for automated experiments and improved data processing."
Spectra that resulted from exposure to the pulse of radio frequencies were complex. But to evaluate the spectra, Ernst employed the Fourier transformation, which new computer technology could employ to reveal the small fluctuations of brightness in the NMR spectra. Subsequently, Ernst's discovery facilitated analysis of substantially more types of nuclei and smaller amounts of materials.
When Ernst took a job in the United States, one of his goals was to leave the academic setting forever. However, in 1968 he returned to Switzerland and the ETH-Z in order to teach. He became an assistant professor in 1970 and a full professor in 1976.
During this period he developed an even more sophisticated contribution to the field of NMR spectroscopy: a technique that enabled a high-resolution, two-dimensional analysis of larger molecules than had previously been accessible to NMR. The technique replaced single pulses of radio frequencies with a sequence of pulses. As a result, scientists could now analyze the three-dimensional structures of organic and inorganic compounds and of proteins and other large biological molecules, or macromolecules. Further, they could study interactions between biological molecules and other substances such as metal ions, water, and drugs, and they were able to identify chemical species and to study the rates of chemical reactions. Ernst's work would provide the basis for the development of magnetic resonance imaging, or MRI, which would become one of the most important diagnostic tools available to medical professionals for diagnoses. It also allowed scientists to gain crucial information about the chemical environment of molecules that they studied.
As a result of the impact of his work, Ernst was honored with the Nobel Prize in Chemistry in 1991. That same year he earned the Louisa Gross Horwitz Prize at Columbia University, along with colleague Kurt Wüthrich. The two scientists received the Horwitz prize for their efforts in developing NMR methods that revealed the behavior and structure of complex biological molecules, or macromolecules. Ernst also received the Wolf Prize in Chemistry in 1991. The awards were an illustration of just how widespread the use of his MRI method had become in clinical studies.
In fact, Ernst learned that he had received the 1991 Nobel Prize in Chemistry while he was onboard an airplane flight to receive the Horwitz Prize. In this rather dramatic set of circumstances, the aircraft's pilot called Ernst to the cockpit to give him the news about the Nobel award.
In awarding Ernst the Nobel Prize, the Royal Swedish Academy of Sciences lauded his contribution to NMR spectroscopy. Specifically, the Academy noted Ernst's development of the methodology of high-resolution NMR spectroscopy as the most important instrumental measuring technique within chemistry. "NMR spectroscopy has during the last twenty years developed into perhaps the most important instrumental measuring technique within chemistry," the Academy noted. Underscoring Ernst's impact, the Academy further stated, "This [development] has occurred because of a dramatic increase in both the sensitivity and the resolution of the instruments, two areas in which Ernst has contributed more than anybody else."
Before and after receiving the Nobel Prize, Ernst continued his research at ETH-Z. Since 1990 he has been president of the institution's Research Council, and he has served as a professor in the laboratory of physical chemistry. Ernst's research has involved molecular interaction, specifically how molecules interact with each other and how they change their shapes. The work brings into play both chemistry and physics as well as quantum mechanics.
In addition to the Nobel Prize, the Wolf prize and the Horwitz prize, Ernst was awarded for Achievements in Magnetic Resonance EAS in 1992. He is a member of many international institutions, including the American Physical Society, the International Society of Magnetic Resonance, the Deutsche Akademie der Naturforscher, the Royal Society of London and the science academies of India and Korea. He also serves on the editorial boards of several journals dealing with magnetic resonance. The book he published on NMR is considered a classic among the leaders in the field. In addition, Ernst holds several patents for his inventions.
Along with chemistry, Ernst still counts music as one of his major interests, and he remains an enthusiastic musician. He also collects Asian art, an interest he cultivated during a trip through Asia in 1968, and is especially interested in Tibetan scroll paintings.
On October 9, 1963, Ernst married Magdalena Kielholz. The couple had two daughters, Anna Magdalena and Katharina Elisabeth, and a son, Hans-Martin. All three children grew up to become educators. He indicated in his autobiography for the Nobel Foundation Website that his wife was especially supportive throughout their marriage and his career. "I am extremely grateful for the encouragement and for the occasional readjustment of my standards of value by my wife Magdalena who stayed with me so far for more than 28 years despite all the problems of being married to a selfish work-addict with an unpredictable temper," he recalled in 1991. "Magdalena has, without much input from my side, educated our three children."
Ernst attributes his scientific success, in large part, to being in the right place at the right time. "Looking back, I realize that I have been favored extraordinarily by external circumstances, the proper place at the proper time in terms of my Ph.D. thesis, my first employment in the [United States] … and in particular having had incredibly brilliant coworkers."
In an interview with Physics Today , he expressed surprise about the impact of his work, NMR spectroscopy and MRI. "I did not expect that it would become as useful and practical as it has," he said.
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