Question

Which of the following complex will show fac & mer isomerism?

• A. $\left[ Co \left( NH _{3}\right)_{3}\left( NO _{2}\right)_{3}\right]$
• B. $\left[ CoCl _{2}( en )_{2}\right]^{+}$
• C. $\left[ Co \left( NH _{3}\right) Cl ( en )_{2}\right]^{2+}$
• D. $\left[ Co \left( NH _{3}\right)_{2} Cl _{2}( en )\right]^{+}$

Answer 1

Answer: (A)

$\left[ Co \left( NH _{3}\right)_{3}\left( NO _{2}\right)_{3}\right]$ compound is of the type $MA _{3} B _{3}$.
This type shows two isomerism, facial and meridian. Both are shown in images.