The one that will show optical activity is: (en = ethane-1, 2-diamine)
(A)(see structure)✓ Correct
(B)(see structure)
(C)(see structure)
(D)(see structure)
Answer: (A)
Solution
A complex is optically active when it has no plane or centre of symmetry, so that it and its mirror image cannot be laid on top of one another. The cis arrangement with the two bidentate ethane-1,2-diamine ligands twisting the octahedron is the one with no such symmetry plane, and it alone is optically active; each of the others carries a mirror plane and so is inactive.
JEE Main · 2019 · 09 Apr 2019 · Shift 1 · Single correct option