Answer to Question #335988 in General Chemistry for ngoma

Question

11. Describe bonding in [Mn(CN)₆]^3- using VBT

           State the hybridisation state of the metal, predict the geometry and magnetic property      of the complex

Answer 1

Oxidation state is Mn3+ in this compound. The electronic configuaration of the cation is 3d4. The CN- ligand tends to bond to the internal 3d-orbitals of the cation. Therefore, there will be 6 bonds between empty Mn3+ orbitals and CN- ligands: two bonds - with empty 3d orbitals of Mn3+, one bond - with empty 4s orbital of Mn3+, and 3 bonds with empty 4p orbitals of Mn3+.

Hybridisation is d2sp3, geometry - octahedral. There will remain three 3d orbitals occupied by four d-electrons of Mn3+: one electron pair and two unpaired electrons. Hence, the compound is paramagnetic with the magnetic moment 2.83 Bohr magnetons