Does either of the following have optical isomers? If so, draw them.
a. trans-
[Co(en)2(NO2)2]+
.
b. cis-
[Co(en)2(NO2)2]+
.
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
To determine if a compound has optical isomers, we need to check if the compound has a chiral center. A chiral center is a carbon atom that is bonded to four different groups.
For compound a: trans-[Co(en)2(NO2)2]+
To determine if it has a chiral center, we need to look at the structure of en, which is the abbreviation for ethylenediamine (H2NCH2CH2NH2).
In this compound, the two en ligands are identical, so they do not provide a chiral center. Additionally, the NO2 groups are also identical. Therefore, the compound does not have a chiral center and does not have optical isomers.
For compound b: cis-[Co(en)2(NO2)2]+
Similarly, the two en ligands in this compound are identical and do not provide a chiral center. The NO2 groups are also identical. Therefore, this compound also does not have a chiral center and does not have optical isomers.
In conclusion, both compounds a and b, trans-[Co(en)2(NO2)2]+ and cis-[Co(en)2(NO2)2]+ respectively, do not have optical isomers.
To determine if a molecule has optical isomers, we need to examine its symmetry and the presence of chiral centers. In a molecule, if it has a plane of symmetry or an internal symmetry element, it does not have optical isomers. However, if it lacks these elements and possesses one or more chiral centers, optical isomers are possible.
For the given coordination complexes:
a. trans-[Co(en)2(NO2)2]+
This complex has a trans arrangement, meaning the ligands are in a straight line and opposite each other. However, it does not have any chiral centers or lack symmetry elements. Therefore, it does not have optical isomers.
b. cis-[Co(en)2(NO2)2]+
This complex has a cis arrangement, meaning the ligands are on the same side. It also does not have any chiral centers or lack symmetry elements. Hence, it also does not have optical isomers.
In both cases, there are no optical isomers present.