Articles

Alfred Werner - Founder of coordination chemistry

Category : General Chemicals
Plublished by : General Chemicals
Catogory : Data Research Analyst, Worldofchemical

Biography & contributions

Alfred Werner was a Swiss chemist and Nobel laureateborn on December 12, 1866 - died on November 15, 1919. In 1913 He won the Nobel Prize in Chemistry for the work on octahedral configuration of transition metal complexes. Werner developed the basis for modern coordination chemistry. He proposed a new theory of variable valence. Werner also worked on complexes with other coordination numbers. In 1914 He reported the first synthetic chiral compound hexol. Werner experimented on many forms of cobalt-ammonia chloride.

Coordination chemistry

Coordination Chemistry is the science concerned with the interactions of organic and inorganic ligands with metal centres. It studies the physical and chemical properties, syntheses and structures of coordination compounds.

Facts about hexol

Hexol is the name for various salts of a coordination complex. Hexol is a cobalt compound that was first prepared by Alfred Werner in 1914 and represented the first non-carbon-containing chiral compound.

Coordination number

It is defined as the total number of points of attachment to the central element (or) a coordination compound is the product of a Lewis acid-base reaction in which a neutral molecule (two or more atoms held together by covalent bonds) or ion (molecule with positive or negative charge) is bonded to a central metal atom or ion.

The central metal is usually a transition metal.

Calculating coordination number

Step 1:

Finding central metal atom in the chemical formula of the coordination compound

Step 2:

Identifying the atom, molecule or ion nearest to central metal atom

Step 3:

Finding the number of atoms, molecules, ions nearest to central metal atom

Step 4:

Finding the total number of nearest neighboring atoms

Coordination number of a complex is influenced by

Relative sizes of the metal ion

Ligands

Cobalt-ammonia chloride

Werner recognized the existence of several forms of cobalt-ammonia chloride. These compounds have different color and other characteristics. The chemical formula has three chloride ions per mole, but the number of chloride ions that precipitate with Ag+ ions per formula is not always three.

Werner thought only ionized chloride ions will form precipitate with silver ion. To distinguish ionized chloride from the coordinated chloride, Werner formulated the Complex formula and explained structure of the cobalt complexes.

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