Does either of the following have optical isomers? If so, draw them.

Question

a. trans-
[Co(en)2(NO2)2]+
.
b. cis-
[Co(en)2(NO2)2]+
.

Answer 1

Both compounds have optical isomers. Here are their drawings:

a. trans-[Co(en)2(NO2)2]+

NO2 NO2
| |
Co -- N N -- Co
| |
H H
/ \
[NH3+] -- C -- C -- Co -- C -- C -- [NH3+]
\ | | /
H NO2 NO2 H

b. cis-[Co(en)2(NO2)2]+

NO2 NO2
| |
Co -- N N -- Co
\ /
[NH3+] -- C -- C -- Co -- C -- C -- [NH3+]
/ | | \
H NO2 NO2 H