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Esta exposicion es un trabajo asigando a los estudiantes de Educacion mencion: Idiomas Modernos: Ingles de la Universidad de Carabobo, Valencia - Venezuela, como parte de las evaluaciones de la asignatura Modulo: Competencias Comunicativas II. Cualquier informacion falsa fue utilizada extrictamente de forma academica. Gracias por su comprension.

ALFRED WERNER
The Nobel Prize in Chemistry 1913

"The Father of Coordination Chemistry"



Werner was born on December 12th 1866 in Mulhouse, a small community in the French province of Alsace. He was the last of four children born to Jean-Adam Werner, a factory foreman and a farmer, and Salome Jeanette Tesche, from German family. Alsace was French when Werner was born but was annexed into Germany during the Franco-Prussian War. Although the Werner family maintained strong patriotic ties with France and continued speak French in their home.

Young Werner began his education in German schools. At age of six he was enrolled at the Ecole Libre des Freres, partly because of his mother’s recent conversion to Catholicism. But this wasn’t the only one, he had a lot of schools and they moved several times. In spite of anybody in his family was interested in the science or chemistry area, their always supported him with his studies and researches. He was a very dedicated and excellent student and chemistry took his interest since he was a child.

When he was 10 years old they moved to a farm, it was an ideal place for having his laboratory, so that he could do all his experiments in a private place. During this time an unpleasant explosion in his laboratory almost ended with his career and he had to move his lab into the barn. In 1878 he entered to the Ecole Professionelle, a technical school and began to study chemistry. He made several projects that helped him to develop his skills and to establish basis for his future investigations.

At the age of 18, he began serving a one-year term compulsory military duty. While he was there, Werner enrolled in two organic chemistry courses taught at the Technical University there. After his tour of duty, he moved to Switzerland to continue his education in chemistry at the Federal Institute of Technology. Werner excelled in chemistry but performed poorly in mathematic, especially geometry. After six semesters of work and a successful preparation he received a diploma in technical chemistry.

In 1889 he was appointed Assistant in Professor Lunge's laboratory at the Zurich Technical High School and he then began to cooperate with Professor Hantzsch in research. In 1890 he took his degree in the University of Zurich with a thesis on the spatial arrangements of the atoms in molecules containing nitrogen.

From 1890 until 1891 he did further work on this subject and visited Paris, where he worked under Professor Berthelot at the Collège de France. In 1892 he returned to Zurich as a lecturer in the Technical High School, and in 1893 he was appointed Associate Professor in the University of Zurich, to succeed Victor Merz and then gave the University lectures on organic chemistry.

In 1895 he became, when he was only 29 years old, Professor of Chemistry in the University, giving the lectures on organic chemistry until, in 1902, he took over the lectures on inorganic chemistry as well. In 1895 he was acquired Swiss nationality and though he was offered posts at Vienna, Basle and Wurzburg, he declined these, preferring to remain in Zurich.

Werner's name will always be associated with the theory of coordination which he established and with his work on the spatial relationships of atoms in the molecule, the foundations of which were laid in the work he did, when he was only 24, for his doctorate thesis in 1892. In this work he formulated the idea that, in the numerous compounds of tervalent nitrogen, the three valence bonds of the nitrogen atom are directed towards the three corners of a tetrahedron, the fourth corner of this being occupied by the nitrogen atom. In 1891 he had published a paper on the theory of affinity and valence, in which he substituted for Kekulé's conception of constant valence, the idea that affnity is an attractive force exerted from the centre of the atom which acts uniformly towards all parts of the surface of the atom.

In 1893 he stated, in a paper on mineral compounds, his theory of variable valence, according to which inorganic molecular compounds contain single atoms which act as central nuclei around which are arranged a definite number of other atoms, radicals or other molecules in a simple, spatial, geometric pattern. The figure which expresses the number of atoms thus grouped round a central nucleus was called by Werner the coordination number, the most important of these coordination numbers being 3, 4, 6 and 8, the number 6 occurring especially often. Thousands of molecular compounds correspond to the number 6 type, and in all of these there is a central atom with coordinated atoms at the corners of an octahedron.

For the next 20 years Werner and his collaborators studied and prepared new series of molecular compounds and studied their configurations, publishing many papers on them, 150 of which were by himself. Finally, his work culminated in the discovery of optically-active isomers of the complexes studied, the existence of which had been forecast by his hypothesis. More than 40 series of optically-active complexes with octahedral symmetry were separated in optically-active forms, with the result that the spatial configuration of the complexes to the coordination number 6 was established as firmly as that of the tetrahedral carbon atom of van 't Hoff and Le Bel. For his work on it Werner was awarded the Nobel Prize for Chemistry for 1913.

Werner was a very sociable man, whose recreations were billiards, chess and the Swiss card game, Jass. He spent his holidays among the mountains and travelled much to attend scientific meetings outside Switzerland. As a lecturer he was a convincing and enthusiastic speaker with a gift for clear explanations of difficult problems. Among his pupils were such distinguished men as Jantsch, Karrer and Pfeiffer. Valuable for others were his books Neuere Anschauungen auf dem Gebiete der anorganischen Chemie (New ideas in inorganic chemistry) and Lehrbuch der Stereochemie (Textbook of stereochemistry), both published in 1904.

In 1894, Werner married Emma Giesker of Zurich, a member of a German family. They had one son, Alfred, and one daughter, Charlotte.In 1913, the year in which he received the Nobel Prize for Chemistry, he was already suffering from arteriosclerosis and by 1915 this had compelled him to give up his general lectures on chemistry and in 1919 he had to give up his Professorship. On November 15, 1919, he died at the early age of 53.

''Werner's coordination theory has been a guiding principle in inorganic chemistry and in the theory of valence since its publication sixty years ago. Indeed, it might have been said to underline our modern concepts of molecular structure. The current theories of acidity, basicity, amphoterism and hydrolysis grew directly from it...''