Van’t Hoff, Jacobus Henricus

Urbain, Georges. La coordination des atomes dans la molecule la symbolique chimique. Paris Hermann, 1933. van t Hoff, Jacobus Henricus. Ansichten uber die organische Chemie. 2 vols. Braunschweig F. Vieweg, 18781881. 

Van der Waals Johannes Diderik (1837-1923) Dutch phys., research on gaseous and liquid phases, determined so-called perfect and real gases, thermodynamic theory of capillarity, know for Van der Waals forces between dielectric molecules van t Hoff Jacobus Henricus (1852-1911) Dutch chem., father of phys. chem., relating thermodynamics to chem. 

Van t Hoff, Jacobus Henricus (1852-1911) Dutch theoretical chemist. Van t Hoff made important contributions to stereochemistry, thermodynamics, the kinetics of chemical reactions and the theory of chemical solutions. In 1874 Van t Hoff initiated the subject of stereochemistry when he postulated that the four chemical bonds which a carbon atom can form are directed toward the corners of a regular tetrahedron. This enabled the phenomenon of optical activity to be understood in terms of the structures of optical isomers. Van t Hoff introduced this idea independently of Joseph le Bel. Many of the contributions of Van t Hoff to thermodynamics, kinetics and solutions were expounded in his book Studies of Chemical Dynamics (1884). This included the application of thermodynamics to chemical equilibrium. He was awarded the first Nobel Prize for chemistry in 1901. 

Pasteur s discovery, as noted above, connected chirality on the macroscopic scale to chirality on the molecular scale. Unlike the chiral morphology of quartz and tartrate crystals, dissymetrie moleculaire is not apparent to the eye, yet Pasteur3 provided the key insight on the essential requirement for molecular chirality well before the advent of structural theory and the asymmetric carbon atom of Jacobus Henricus van t Hoff ... 

The Fischer projection is a convenient way of showing the configurations of the linear forms of monosaccharides. This convention depicts the concepts of stereochemistry established by Jacobus Henricus van t Hoff and Joseph Achille Le Bel in a simplified form. While these abbreviated structural formulas are simple to write and easy to visualize, there are some guidelines that should be taken into account when converting a three-dimensional structure into a Fischer projection and in its manipulation (Fig. 1.2) ... 

Refs. [i] http //nobelprize.org/index.html [ii] Partington JR (1961) A history of chemistry, 4 vols. Macmillan, London [Hi] LaidlerKJ (1993) The world of physical chemistry. Oxford University Press, Oxford, p 453 [iv] LaidlerKJ (1985) Arch Hist Exact Sci 32 43 [v] Cohen E (1912) Jacobus Henricus van t Hoff. Sein Leben und Wirken. Akademische Ver-lagsgesellschaft, Leipzig... 

The importance of geometry in understanding molecular structure was illustrated long ago by the pioneering work of Louis Pasteur, Achille Joseph Le Bel, and Jacobus Henricus van t Hoff. However, it was only after Harry L. Frisch and Edel Wasserman s now classic paper,4 a century later, that the topology of molecular structures is also being considered to be significant. 

The technique of isomer counting used by Wemer to prove the configuration of cobalt-ammines and other complexes did not originate with him, but had been used earlier by Wilhelm Kdmer for benzene derivatives in 1874, and was also suggested by Jacobus Henricus van t Hoff in 1875. However, the technique of comparing the number and type of isomers actually prepared with the number and type theoretically predicted for different configurations probably attained its zenith with Wemer. Not only did he use this method to discredit completely the chain theory bnt also to... 

Paper 8 Jacobus Henricus van t Hoff, A Suggestion Looking to the Extension into Space of the Structural Formulas at Present Used in Chemistry. And a Note upon the Relation between the Optical Activity and the Chemical Constitution of Organic Compounds. ... 

JACOBUS HENRICUS VAN T HOFF (1852-1911). From Jacobus Henricus varCt Hoff Sein Leben und Wirken by Ernst Cohen. Leipzig, 1912. Courtesy of the publisher, Akademische Verlags-gesellschaft, Frankfurt/Main. 

From the chirality standpoint the next fundamental development occurred in 1874, when the tetrahedral carbon atom was proposed as a basis for molecular chirality by the Dutch and French chemists Jacobus Henricus van t Hoff (1852— 1911) [47, 48] and Joseph Achille LeBel (1847-1930) [49], respectively, independently and almost simultaneously. The discovery of the asymmetric carbon atom (van t Hoff s terminology) finally provided the explanation for the existence of optical isomers and for the chiral nature of the molecules of optically active substances, including many drugs. In his original 1874 pamphlet proposing the tetrahedron [47] van t Hoff listed camphor as a chiral molecule, but the structure he gave (19) was incorrect. 

Jacobus Henricus van t Hoff hundred years impact on stereochemistry 01AG(E)3783. 

This method has been used for many years since it was first suggested in 1884 by the Dutch chemist and first Nobel prizewinner in chemistry (1901) Jacobus Henricus van t Hoff who made substantial contributions in both physical chemistry and stereochemistry. The method is sometimes named after him. Alternatively, as here, it is described by the term differential which reflects the fact that, in the language of calculus, rate equations are dijferential equations. However, this is not to imply that the method involves calculus but simply to indicate that it seeks directly to determine the form of experimental rate equations without changing them into another form (as we shall do later in Section 5.3.3). 

The solution to the problem was discovered in 1874 by Jacobus Henricus van t Hoff, 22 years old, and Joseph Achille Le Bel, age 27. Although they both worked in the laboratory of Adolph Wurtz in Paris in 1874, their discoveries were completely independent. Van t Hoff would continue to make major contributions to physical chemistry and won its first Nobel Prize (1901) for his discovery of laws of osmotic pressure of solutions. 

The factor is named for the Dutch theoretical chemist Jacobus Henricus Van t Hoff (1852-1911). 

Jacobus Henricus van t Hoff (1852-1911), Netherlands. In recognition of the extraordinary services he has rendered by the discovery of the laws of chemical dynamics and osmotic pressure in solutions. ... 

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