During the last fifty years, advances in this
area, have provided development of new concepts and models of bonding and
molecular structure, novel breakthroughs in chemical industry and vital
insights into the functioning of critical components of biological systems The first systematic attempt at explaining the formation, reactions, structure
and bonding of a coordination compound was made by A Werner His theory
postulated the use of two types of linkages (primary and secondary) by a
metal atom/ion in a coordination compound