Jacobus Henricus van 't Hoff

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Dutch theoretical chemist (1852–1911)

Van't Hoff was born at Rotterdam in the Netherlands, the son of a physician. He studied at Delft Polytechnic and the University of Leiden before going abroad to work with August Kekulé in Bonn (1872) and with Charles Adolphe Wurtz in Paris (1874), where he met Joseph-Achille Le Bel. In 1878 he was appointed to the Amsterdam chair of chemistry where he remained until moving to the University of Berlin in 1896.

In 1874 van't Hoff published a paper entitled A Suggestion Looking to the Extension into Space of the Structural Formulas at Present Used in Chemistry, which effectively created a new branch of science – stereochemistry. The problem began with the discovery of optically active compounds. Louis Pasteur later established the asymmetry of crystals of tartaric acid: some would rotate polarized light to the right and others to the left. This was explained by the actual asymmetry of the crystal: the crystals were mirror images of each other. Pasteur thought that the molecules themselves were asymmetric but could offer no proof. This would explain the further problem of the optical activity of noncrystalline solutions. Van't Hoff solved these problems and offered an account of molecular asymmetry by concentrating on the structure of the carbon atom, newly established by Kekulé. He announced (1874) that the four chemical bonds that carbon can form are directed to the corners of a tetrahedron. With this structure, certain molecules can have left- and right-handed isomers, which have opposite effects on polarized light. It also explained why certain isomers do not occur.

Van't Hoff's account of molecular structure was attacked by Hermann Kolbe but a similar theory was put forward simultaneously by Joseph-Achille Le Bel, independently of van't Hoff. Despite the hostility, his ideas were soon vindicated by Emil Fischer's researches into sugars in the 1880s.

Major contributions were also made by van't Hoff to the thermodynamics and kinetics of solutions. Many of these results are reported in his book Etudes de dynamique chimie (1884; Studies in Chemical Kinetics). He had the central insight in 1886 that there is a similarity between solutions and gases provided that osmotic pressure is substituted for the ordinary pressure of gases, and derived laws for dilute solutions similar to those of Robert Boyle and Joseph Gay-Lussac for gases. This fundamental result could be used to determine the molecular weight of a substance in solution.

In 1901 van't Hoff was awarded the first Nobel Prize for chemistry.

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).

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Jacobus Henricus van 't Hoff
Jacobus Henricus van 't Hoff
Born	30 August 1852 Rotterdam, Netherlands
Died	1 March 1911 (aged 58) Steglitz, Berlin, Germany
Residence	Netherlands German Empire,
Nationality	Netherlands
Fields	Physical chemistry Organic chemistry
Institutions	Veterinary College in Utrecht University of Amsterdam University of Berlin
Alma mater	Delft Polytechnic Institute University of Leiden University of Bonn University of Paris University of Utrecht
Doctoral advisor	Eduard Mulder
Known for	Chemical kinetics, Stereochemistry
Notable awards	Nobel Prize for Chemistry (1901)

Jacobus Henricus van 't Hoff (30 August 1852 – 1 March 1911) was a Dutch physical and organic chemist and the winner of the inaugural Nobel Prize in chemistry. His research on chemical kinetics, chemical equilibrium, osmotic pressure and stereochemistry are among his most notable achievements. Through these achievements, Van 't Hoff helped found the discipline of physical chemistry as it is known today.

Contents 1 Biography 2 Career 2.1 Contributions to chemistry 2.2 The Nobel Prize in Chemistry 3 Honours and awards 4 See also 5 References 6 Further reading 7 External links

Biography

He was born in Rotterdam, Netherlands, the son of a medical doctor. From a young age he was interested in science and nature; he frequently took part in botanical excursions, and his receptiveness for philosophy and his predilection for poetry were already apparent in his early school years. (Lord Byron was his idol.) Against the wishes of his father, he went to study chemistry, first at the Delft Polytechnic Institute, then at the University of Leiden, then to Bonn, Germany (where he studied with Friedrich Kekulé), then Paris (where he studied with C. A. Wurtz), finally receiving his doctorate under Eduard Mulder at the University of Utrecht in 1874^[1]. In 1878 van 't Hoff married Johanna Francina Mees. They had two daughters, Johanna Francina (b. 1880) and Aleida Jacoba (b. 1882), and two sons, Jacobus Hendricus (b. 1883) and Govert Jacob (b. 1889).

Career

Contributions to chemistry

Before receiving his doctorate, van 't Hoff had already published the first of his important contributions to organic chemistry. In 1874 he accounted for the phenomenon of optical activity by assuming that the chemical bonds between carbon atoms and their neighbors were directed towards the corners of a regular tetrahedron. This three-dimensional structure perfectly accounted for the isomers found in nature (stereochemistry). He shares credit for this idea with the French chemist Joseph Le Bel, who independently came up with the same idea.

Van 't Hoff published his work on the geometry of science in his book La chimie dans l'éspace in 1874. At the time, his theory was considered an extraordinary claim in science, and was criticized strongly by the scientific community. One such critic was the renowned editor of the German Journal für praktische Chemie, Adolph Kolbe, who stated:

"A Dr. H. van ’t Hoff of the Veterinary School at Utrecht has no liking, apparently, for exact chemical investigation. He has considered it more comfortable to mount Pegasus (apparently borrowed from the Veterinary School) and to proclaim in his ‘La chimie dans l’espace’ how the atoms appear to him to be arranged in space, when he is on the chemical Mt. Parnassus which he has reached by bold flight."

However, van 't Hoff's work was revolutionary, and became indispensable in science.

Van 't Hoff in the 1900s.

In 1884 van 't Hoff published his research on chemical kinetics, naming it Études de Dynamique chimique ("Studies in Chemical Dynamics"), in which he described a new method for determining the order of a reaction using graphics, and applied the laws of thermodynamics to chemical equilibria. He also introduced the modern concept of chemical affinity. In 1886 he showed a similarity between the behaviour of dilute solutions and gases. Until 1895 he worked on Svante Arrhenius's theory of the dissociation of electrolytes. On 1896 he became professor to the Prussian Academy of Science at Berlin. His studies of the salt deposits at Stassfurt contributed to Prussia's chemical industry. In 1887 he and German chemist Wilhelm Ostwald founded an influential scientific magazine named Zeitschrift für physikalische Chemie ("Journal of Physical Chemistry"). He also worked with Svante Arrhenius on salt solutions and their ions.

The Nobel Prize in Chemistry

Van 't Hoff became a lecturer in chemistry and physics at the Veterinary College in Utrecht. He then became a professor of chemistry, mineralogy, and geology at the University of Amsterdam for almost 18 years before eventually becoming the chairman of the chemistry department. In 1896 van 't Hoff moved to Germany where he finished his career at the University of Berlin in 1911. In 1901 he received the first Nobel Prize in chemistry for his work with solutions. This can generally be summarized by stating that very dilute solutions follow mathematical laws that closely resemble the laws describing the behavior of gases.

Honours and awards

Van 't Hoff in the 1900s at the height of his career.

In 1885 he was appointed member of the Royal Netherlands Academy of Sciences. Other distinctions included the honorary doctorates of Harvard and Yale 1901, Victoria University, Manchester 1903, Heidelberg 1908; the Davy Medal of the Royal Society 1893 (along with Le Bel), Helmholtz Medal of the Prussian Academy of Sciences 1911; he was also appointed Chevalier de la Légion d'honneur 1894, Senator der Kaiser-Wilhelm-Gesellschaft (1911). Van 't Hoff was also honorary member of the British Chemical Society in London, the Royal Academy of Sciences, in Göttingen 1892, American Chemical Society 1898, and the Académie des Sciences, in Paris 1905.

He was indeed a prominent scientist of his time. Of his numerous distinctions, he regarded his winning of the first Nobel Prize in Chemistry as the culmination of his career.

Van 't Hoff died at the age of 58, on 1 March 1911, at Steglitz near Berlin from tuberculosis.

See also

Wikimedia Commons has media related to: Jacobus van 't Hoff

• van 't Hoff factor
• van 't Hoff equation
•  "van't Hoff, Jacobus Hendricus". Encyclopædia Britannica (11th ed.). 1911. 

References

• E. W. Meijer (2001). "Jacobus Henricus van 't Hoff; Hundred Years of Impact on Stereochemistry in the Netherlands". Angewandte Chemie International Edition 40 (20): 3783. doi:10.1002/1521-3773(20011015)40:20<3783::AID-ANIE3783>3.0.CO;2-J. 
• Trienke M. van der Spek (2006). "Selling a Theory: The Role of Molecular Models in J. H. van 't Hoff's Stereochemistry Theory". Annals of Science 63 (2): 157. doi:10.1080/00033790500480816. 
• Kreuzfeld HJ, Hateley MJ. (1999). "125 years of enantiomers: back to the roots Jacobus Henricus van 't Hoff 1852-1911". Enantiomer 4 (6): 491–6. 

1. ^ Entry in Digital Album Promotorum of Utrecht University

Further reading

• Patrick Coffey, Cathedrals of Science: The Personalities and Rivalries That Made Modern Chemistry, Oxford University Press, 2008. ISBN 978-0-19-532134-0

External links

• Nobel Lecture Osmotic Pressure and Chemical Equilibrium from Nobelprize.org website
• Karl Grandin, ed.. "Jacobus Henricus van 't Hoff Biography". Les Prix Nobel. The Nobel Foundation. http://nobelprize.org/nobel_prizes/chemistry/laureates/1901/hoff-bio.html. Retrieved 2008-08-15. 

v • d • e Nobel Laureates in Chemistry Jacobus van 't Hoff (1901) · Emil Fischer (1902) · Svante Arrhenius (1903) · William Ramsay (1904) · Adolf von Baeyer (1905) · Henri Moissan (1906) · Eduard Buchner (1907) · Ernest Rutherford (1908) · Wilhelm Ostwald (1909) · Otto Wallach (1910) · Marie Curie (1911) · Victor Grignard / Paul Sabatier (1912) · Alfred Werner (1913) · Theodore Richards (1914) · Richard Willstätter (1915) · Fritz Haber (1918) · Walther Nernst (1920) · Frederick Soddy (1921) · Francis Aston (1922) · Fritz Pregl (1923) · Richard Zsigmondy (1925) Complete roster · 1901–1925 · 1926–1950 · 1951–1975 · 1976–2000 · 2001–present

Persondata
NAME	Hoff, Jacobus Henricus van 't
ALTERNATIVE NAMES
SHORT DESCRIPTION	Chemist and Nobel laureate
DATE OF BIRTH	30 August 1852
PLACE OF BIRTH	Rotterdam, Netherlands
DATE OF DEATH	1911-3-1
PLACE OF DEATH	Steglitz, Berlin, Germany

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