The Dutch physical chemist Jacobus Hendricus Van't Hoff (1852-1911) pioneered in the development of stereochemistry.

Jacobus Hendricus Van't Hoff was born in Rotterdam on Aug. 30, 1852. He developed an early interest in science, and in spite of the opposition of his father, who was a medical doctor, he studied chemistry at a polytechnic school and then at the University of Leiden. From the Netherlands he journeyed to Germany and then to Paris for further study, finishing his doctorate at the University of Utrecht in 1874.

Just prior to the awarding of the degree, however, Van't Hoff published a surprising scientific paper on the optical activity of certain organic compounds. This phenomenon (stereochemistry) of organic compounds can be described briefly by reference to the two forms of tartaric acid. They are the same in chemical formula, but in solution one form rotates a beam of polarized light to the left, and the other rotates it to the right. Pasteur had observed this phenomenon years earlier and suggested that the compound was actually made up of crystals which were mirror images of each other, but this explanation did not seem to have any application to compounds in solution. Van't Hoff's contribution was to describe asymmetry in molecules, not in crystals, and he showed how this was possible if one considers the carbon atom as having four linkages which do not lie in a plane but are directed toward the four angles of a tetrahedon. In this way, the carbon atom achieves a three-dimensional form, and the attachment to it of different types of chemical groupings establishes asymmetric molecules and compounds.

Van't Hoff became a lecturer in chemistry at the Veterinary College in Utrecht. From there he went to the University of Amsterdam, and he ended his career at the University of Berlin, where he taught and engaged in research from 1896 to 1911. In 1901 he received the first Nobel Prize in chemistry, which was awarded him for his work with solutions. His achievements in this field were made during the second part of his scientific career, when he was a physical chemist. In the first part of his career, it may be said that he was an organic chemist. The results of his research in chemical thermodynamics were published in Studies in Chemical Dynamics (1884).

Van't Hoff's work on the theory of solutions formed the major part of his creative research in physical chemistry. He was able to show that, in very dilute solutions, the laws of gases may be applied to the molecules. Before his work, chemists had possessed only vague ideas about molecular behavior in solutions; Van't Hoff's research cleared up many questions. Van't Hoff had a generalizing and speculative mind which gave him insights into the newly developing field of physical chemistry. He died on March 1, 1911.

Further Reading

• Ernst Cohen, who wrote the definitive biography of Van't Hoff in German, contributed a biographical sketch of the scientist in Eduard Farber, ed., Great Chemists (1961). Van't Hoff is mentioned in Isaac Asimov's survey, A Short History of Chemistry (1965).