# Will the following complex show optical isomerism

So there is this question which asks whether the following complex

$$\ce{[Co(NH3)4Br2]+}$$

will show optical isomerism or not.

According to my knowledge it will show optical isomerism in cis form only and not in trans form so overall the compound shouldn’t be optically active.

This what I hav been taught. And moreover shouldn’t it be optically active in every scenario to be called so?

But the ans says that it shows optical isomerism. I don’t understand why.. is my understanding wrong?

• OK, you seem to agree that the trans form does not show optical isomerism. Now what about cis form? Why would it be chiral, when it has an obvious plane of symmetry? Jan 30 '20 at 9:42
• Alright I agree so then is the answer wrong? Cause if I remember correctly this question came in JEE exam (a prestigious exam in India)@IvanNeretin Jan 30 '20 at 10:16
• Yes, the answer is wrong. None of the forms is optically active. Jan 30 '20 at 11:50