Coordination sphere
![cis-[CoCl2(NH3)4]+ The colored atoms form a coordination sphere around the ion of cobalt](/uploads/202502/09/Cis-dichlorotetraamminecobalt(III)4651.png)
![Hexamminecobalt(III) chloride([Co(NH3)6]Cl3)](/uploads/202502/09/CoA6Cl34651.png)
In coordination chemistry, the coordination sphere refers to a central atom or ion and an array of molecules or anions, the ligands, around. Molecules that are attached noncovalently to the ligands are called the second coordination sphere.