Explain with two examples the following
Coordination sphere.

Explanation

Coordination sphere : The central `"atom"//"ion"` and the ligands attached to it are enclosed in square bracket and is collectively termed as the coordination sphere. The ionisable groups are written outside the bracket and are called counter ions. For example, in the complex `K_4[Fe(CN_6)]`, the coordination sphere is `[Fe(CN)_6]^(4-)` and the counter ion is `K^(+)`.