write the Werner theory of coordination complexes
Answers
The first attempt to explain nature of bonding in coordination compounds was put forth by Werner. The postulates of Werner theory are as follows. Postulate (i) Unlike metal salts, the metal in a complex possesses two types of valencies : primary (ionizable) valency and secondary (nonionizable) valency. Postulate (ii) The ionizable sphere consists of entities which satisfy the primary valency of the metal. Primary valencies are generally satisfied by anions. Postulate (iii) The secondary coordination sphere consists of entities which satisfy the secondary valencies and are non ionizable.
The secondary valencies for a metal ion are fixed and satisfied by either anions or neutral ligands. Number of secondary valencies is equal to the coordination number. Postulate (iv) The secondary valencies have a fixed spatial arrangement around the metal ion.
Answer:
The important postulates of Werner's theory are as follows: In coordination compounds, the central metal or metal atoms exhibit two types of valency, For Example: The primary valency and the secondary valency. The primary valency corresponds to oxidation state and the secondary valency corresponds to coordinate number.