Question

Write the IUPAC name of the following complex:
[Co(NH₃)₅(CO₃)]Cl.

Hint:

The IUPAC naming system for coordination compounds includes the names of the ligands, the metal, its oxidation state, and the counter-ion.

Answer 1

To solve the problem, we need to write the IUPAC name of the given complex: [Co(NH₃)₅(CO₃)]Cl.

1. Analyzing the Complex:
The given complex consists of a cobalt (Co) metal ion, ammonia (NH₃) ligands, a carbonate (CO₃²⁻) ligand, and a chloride (Cl⁻) counterion. The ammonia ligands are neutral, while the carbonate ion is a bidentate ligand that is negatively charged, and the chloride ion is an anion that balances the charge of the complex.

2. Naming the Ligands:
In IUPAC nomenclature, the ligands are named first, in alphabetical order, followed by the name of the metal ion. The ligands are: - Ammonia (NH₃) is named "ammine." - Carbonate (CO₃²⁻) is named "carbonato." - The chloride ion (Cl⁻) is named "chlorido."

3. Naming the Metal Ion:
The metal ion is cobalt (Co), and since it has a +3 oxidation state in this complex, we use the Roman numeral III to indicate this. The metal is followed by the suffix "ate" because the complex has a negative charge due to the chloride ion. The metal's name in the complex will be "cobaltate."

4. Putting It All Together:
Now, we can write the full IUPAC name of the complex: 
- First, we list the ligands in alphabetical order: "ammine" and "carbonato." 
- Then, we name the metal as "cobalt," followed by the oxidation state of cobalt in Roman numerals. 
- Finally, we mention the counterion, "chlorido." 
Thus, the IUPAC name of the complex [Co(NH₃)₅(CO₃)]Cl is pentamminecarbonatocobalt(III) chloride.