Question

Which one of the following complexes is an outer orbital complex ?

• A. ${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$
• B. ${\left[Mn(CN{)}_6\right]}^{4+}$
• C. ${\left[Fe(CN{)}_6\right]}^{4-}$
• D. ${\left[Ni{\left(N{H}_3\right)}_6\right]}^{2+}$

Answer 1

Answer: (D)

${\left[Fe(CN{)}_6\right]}^{4-},{\left[Fe(CN{)}_6\right]}^{4-}$ and ${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$ involve $d^{2}s{p}^3$ hybridization and are inner orbital complexes.
The compound ${\left[Ni{\left(N{H}_3\right)}_6\right]}^{2+}$ involves $s{p}^3{d}^2$ hybridization and is outer orbital complex.