Let’s discuss inner orbital complexing taking an example, [Co(CN)6]3- ion
- In this complex oxidation state of cobalt is +3
Valence shell electronic configuration is
- Magnetic moment measurement indicates that [Co(CN)6]3-C ion is diamagnetic(given). So that all the d-electrons arranged in such a way, that no unpaired electron is left in the d-orbital.
- In other words as CN– ion is a strong ligand, it causes the pairing of 3d-electrons.
- Here two vacant 3d-orbital combine with the vacant 4s and 4p orbital to form six d2sp3
- Then six hybrid orbital overlap with six filled orbital of CN– ligand, one on each of the ligand and thus six coordinate covalent bonds are formed which gives d2sp3 hybridization.
- As inner d-orbitals are involved in hybridization, it gives inner orbital octahedral geometry.
Test your understanding:
Explain hybridisation in,
[Co(NO2)6]4- (one unpaired electron)
[Mn(CN)6]3- (two unpaired electron)
[Cr(CN)6]3-C (paramagnetic corresponding to three unpaired electron)