Understanding Co(NH3)6^2+
Co(NH3)6^2+ is a coordination compound where cobalt is surrounded by six ammonia (NH3) ligands. The oxidation state of cobalt in this complex is +3, and it adopts an octahedral geometry.
Inner Orbital Complex Explanation
- d-Orbital Configuration: Cobalt typically has the electron configuration [Ar] 3d^7 4s^2. In the +3 oxidation state, it loses two 4s electrons and one 3d electron, resulting in a 3d^6 configuration.
- Crystal Field Splitting: In an octahedral field created by the NH3 ligands, the 3d orbitals split into two sets: the lower-energy t2g (three orbitals) and the higher-energy eg (two orbitals). For Co^3+ with a 3d^6 configuration, all three t2g orbitals are filled (6 electrons), and the eg orbitals remain empty.
- Pairing of Electrons: Ammonia is a strong field ligand, which means it can cause significant splitting of the d orbitals. This strong field effect leads to the pairing of electrons in the lower-energy t2g orbitals, resulting in the absence of unpaired electrons in the complex.
Inner Orbital Complex Characteristics
- Octahedral Geometry: The arrangement of six NH3 ligands around Co^3+ leads to an octahedral geometry.
- Absence of Unpaired Electrons: The pairing of electrons in the t2g orbitals means that Co(NH3)6^2+ does not have any unpaired d electrons, characteristic of an inner orbital complex.
- Magnetic Properties: Due to the absence of unpaired electrons, Co(NH3)6^2+ is diamagnetic.
In summary, Co(NH3)6^2+ is an inner orbital complex due to the strong field nature of NH3 ligands, which facilitates the pairing of electrons in the t2g orbitals, eliminating any unpaired d electrons.