Explain with two examples each of the following: coordination entity, ligand, coordination number, coordination polyhedron, homoleptic and heteroleptic.

Explanation

Co-ordination entity : The species present within the square bracket is called co-ordination entity. For example, `[Co(NH_3)_6]^(3+) and [Co(NH_3)_6]Cl_3`.
Co-ordination polyhedron: The spatial arrangement of the ligand atoms which are directly attached to the central atom is called co-ordination polyhedron. For example, octahedral geometry of `[Co(NH_3)_6]^(3+)` and tetrahedral geometry of `Ni(CO)_4`.
Homoleptic complex : The complex in which central metal is attached to only one kind ofligands is called homoleptic complex.
For example, `[Co(NH_3)_6]^(3+) and [Fe(CN)_6]^(2+)`.
Heterolptic complex : The complex in which central metal is attached to more than one kind of ligands is called heteroleptic complex.
For example , `[Co(NH_3)_4Cl_2]^(+) and K_2 [ Zn(OH)_4]`.