The synthesis protocol for the coordination compound formed between Copper II and ethylenediamine en involves the formation of a complex with the general formula [Cu en _x]^2+, where x is the number of ethylenediamine ligands coordinated to the copper II ion. A common complex formed is [Cu en _2]^2+.Synthesis Protocol:1. Start with an aqueous solution of a copper II salt, such as copper II sulfate CuSO45H2O or copper II chloride CuCl22H2O .2. Dissolve the copper II salt in a minimal amount of distilled water to form a clear solution.3. Prepare a separate solution of ethylenediamine en in distilled water. The concentration of the en solution should be at least twice the concentration of the copper II solution to ensure complete complexation.4. Slowly add the ethylenediamine solution to the copper II solution while stirring. The solution will change color as the complex forms, typically to a deep blue or purple color.5. Continue stirring for a few minutes to ensure complete complexation.6. Filter the solution to remove any unreacted copper II salt or other impurities.7. Allow the solution to evaporate slowly at room temperature or in a crystallization dish to obtain crystals of the coordination compound.Characterization:1. Infrared IR Spectroscopy: The IR spectrum of the complex will show characteristic peaks corresponding to the ethylenediamine ligand, such as the NH2 bending and stretching vibrations.2. Ultraviolet-Visible UV-Vis Spectroscopy: The UV-Vis spectrum of the complex will show a d-d transition band corresponding to the copper II ion, typically in the visible region, which is responsible for the color of the complex.3. X-ray Crystallography: X-ray crystallography can be used to determine the crystal structure of the complex, providing information about the coordination geometry around the copper II ion and the arrangement of the ethylenediamine ligands.4. Elemental Analysis: Elemental analysis can be used to determine the empirical formula of the complex, confirming the stoichiometry of the copper II and ethylenediamine components.5. Magnetic Susceptibility: The magnetic susceptibility of the complex can provide information about the number of unpaired electrons in the copper II ion, which can be used to confirm the oxidation state and coordination geometry of the complex.