On the basis of VBT explain the hybridization, geometrical shape and magnetic property of `[CoF_(6)]^(3-)`, hexafluorido cobaltate (III) ion.

Explanation

Electronic configuration of Co : `[Ar]" "3d^(7)" "4s^(2)" "4p^(0)" "4d^(0)`
`" "Co^(3+): [Ar]" "3d^(6)" "4s^(0)" "4p^(0)" "4d^(0)`

Under the influence of weak field fluoride ligands, in 3d orbitals of .Co. electron pairing take place to Hund.s rule and cobalt undergo `sp^(3)d^(2)` hybridisation to give six hybrid orbitals.

▪ Six `F^(-)` ligands donate six pairs of electrons and these electrons occupy in vacant hybrid orbits.
▪ Due to `sp^(3)d^(2)` hybridisation the complex has octahedral geometry
▪ Due to presence of unpaired electrons, the complex is paramagnetic.