Which of the following is an outer d-orbital or high spin complex ?

Options

A. `[Co(NH_(3))_(6)]^(3+)`
B. `[Ni(CN)_(4)]^(2-)`
C. `[NiCI_(4)]^(2-)`
D. `[CoF_(6)]^(-3)`

Explanation

(d) `[Co(NH_(3))_(6)]^(3+)` and `[Ni(CN)_(4)]^(2-)` are inner d-orbital or low spin complex and `[NiCI_(4)]^(2-)` complex has `sp^(3)` -hybridisation and has tetrahedral geometry while `[CoF_(6)]^(3-)` is outer d-orbital or high spin complex .
`[CoF_(6)]^(3-),Co=4s^(2),3d^(7),4p^(0),Co^(3+)=3d^(6),4s^(0),4f^(0)`

Here, `F^(-)` is a weak ligand so no pairing of electron takes place