Q. The complex $[CoF_{6}]^{4-}$ is
J & K CETJ & K CET 2010Coordination Compounds
Solution:
In $\left[ CoF _{6}\right]^{4-}$, central metal
Co is present as $Co ^{2+}$.
$C o^{2+}=[A r] 3 d^{7} 4 s^{0}$
Because of the presence of three unpaired electrons, the complex is paramagnetic. Moreover, $F^-$
ions occupy outer $d$-orbitals (ie, $nd$-orbitals), thus it is an outer orbital complex.
