The structure of complex \(CuSO_{4}, 5H_{2}O\) or \(Cu(H_{2}O)SO_{4} 4H_{2}O\) is as
In crystalline form, four water molecules are coordinated with \(Cu\) atom forming a square-planar geometry and the two \(O\) atoms of sulphate ion complete the distorted octahedron. The fifth water molecule is attached through \(H\)-bonding between one of the coordinated \(H_{2}O\) molecule and one of the sulphate ion
The geometry of copper (II) in copper sulphate pentahydrate is deformed octahedral.
The copper is connected to two oxygen atoms from two sulphate ions and four water molecules in a square-planar geometry, as can be seen in the structure. Another way to put it is that one H2O molecule is H-Bonded to sulphate ions in this situation.
Therefore, four water molecules are in coordination with the Cu2+ ion, while the fifth water molecule is hydrogen-bonded to the oxygen of the sulphate ion. Last but not least, the fifth water molecule is not coordinated, has a hydrogen bond, and is firmly entrenched in a crystal.
Thus, we may say that just four water molecules are coordinated, and the lone hydrogen bond is between the fifth and sixth molecules.
A coordination compound holds a central metal atom or ion surrounded by various oppositely charged ions or neutral molecules. These molecules or ions are re-bonded to the metal atom or ion by a coordinate bond.
A coordination entity composes of a central metal atom or ion bonded to a fixed number of ions or molecules.
A molecule, ion, or group which is bonded to the metal atom or ion in a complex or coordination compound by a coordinate bond is commonly called a ligand. It may be either neutral, positively, or negatively charged.