Suraj Prasad
Last Activity: 10 Years ago
A coordination complex is the product of a Lewis acid-base reaction in which neutral molecules or anions (called ligands) bond to a central metal atom (or ion) by coordinate covalent bonds.
Ligands are Lewis bases - they contain at least one pair of electrons to donate to a metal atom/ion. Ligands are also called complexing agents.Metal atoms/ions are Lewis acids - they can accept pairs of electrons from Lewis bases.Within a ligand, the atom that is directly bonded to the metal atom/ion is called the donor atom.A coordinate covalent bond is a covalent bond in which one atom (i.e., the donor atom) supplies both electrons. This type of bonding is different from a normal covalent bond in which each atom supplies one electron.If the coordination complex carries a net charge, the complex is called a complex ion.Compounds that contain a coordination complex are called coordination compounds.
Coordination compounds and complexes are distinct chemical species - their properties and behavior are different from the metal atom/ion and ligands from which they are composed.
The coordination sphere of a coordination compound or complex consists of the central metal atom/ion plus its attached ligands. The coordination sphere is usually enclosed in brackets when written in a formula.