- Person
- Jerome Karle
- Lived
- 1918–2013
- Field
- Chemistry, crystallography
- From
- American
The story
Jerome Karle was born Jerome Karfunkle in New York in 1918 into a Jewish family of Eastern European immigrants. He studied at the tuition-free City College of New York, where Herbert Hauptman was a classmate, and after doctoral work in chemistry at the University of Michigan he joined the Naval Research Laboratory in Washington with his wife, the chemist Isabella Karle, in 1946. Hauptman joined them there in 1947.
X-ray crystallography reveals the arrangement of atoms in a molecule by shining X-rays through a crystal and recording the pattern of scattered spots. The brightness of each spot can be measured, but the phase of each scattered wave is lost, and without phases the pattern cannot be turned into a picture of the atoms. For decades this phase problem made structure determination slow and laborious, and many scientists believed it could not be solved from the measured data alone.
Karle and Hauptman started from the fact that the density of electrons in a crystal can never be negative. From that they derived relationships among the measured intensities and used probability theory to estimate the phases directly. They published the main ideas in a 1953 monograph, Solution of the Phase Problem I. The reception was sceptical; Karle later wrote that many fellow scientists did not believe a word they said. In the 1960s, largely through Isabella Karle’s work, the group developed the symbolic addition procedure, which made the methods practical for real crystals, and by the 1970s laboratories worldwide had adopted them.
Karle and Hauptman shared the 1985 Nobel Prize in Chemistry. Karle felt that Isabella’s contribution deserved a share as well. With computers, direct methods became the standard way to solve the structures of small and medium-sized molecules, and they have played a major role in developing new medicines and materials. Karle later also developed theory for multiple-wavelength anomalous dispersion, now widely used to solve protein structures.
Why it matters
Direct methods let chemists and drug developers determine the three-dimensional structures of new molecules quickly, helping them confirm what they have made and design new medicines and materials.
About Jerome Karle
Brooklyn-born chemist who, with Herbert Hauptman, created the direct methods that let scientists read molecular structures from X-ray data, now routine in drug development. Nobel Prize 1985.
Sources
- Jerome Karle, Biographical NobelPrize.org
- Jerome Karle obituary Physics Today
- Jerome Karle obituary American Crystallographic Association
- Jerome Karle Wikipedia
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