which of the following molecules can have optical isomers?
a. CH2Cl2
b. H2NCH(CH3)COOH
c. ClCH(OH)CH2Cl
is b and c
To determine which of the given molecules can have optical isomers, we need to consider two criteria:
1. Chiral Centers: Optical isomers, also known as enantiomers, occur when a molecule contains chiral centers. A chiral center is an atom that is bonded to four different groups.
2. Symmetry: For a molecule to have optical isomers, it needs to lack an internal plane of symmetry. A molecule with an internal plane of symmetry is achiral and cannot have optical isomers.
Let's analyze each given molecule:
a. CH2Cl2:
- This molecule does not have any chiral centers because the carbon atoms are bonded to the same groups (two hydrogens and two chlorine atoms).
- Additionally, CH2Cl2 has a plane of symmetry through its carbon and hydrogen atoms, making it achiral.
- Therefore, CH2Cl2 cannot have optical isomers.
b. H2NCH(CH3)COOH:
- This molecule has a chiral center, marked by the asterisk (*) in the structural formula, specifically the central carbon atom bonded to four different groups: H, N, C(CH3)COOH.
- Moreover, H2NCH(CH3)COOH lacks an internal plane of symmetry.
- Therefore, H2NCH(CH3)COOH can have optical isomers.
c. ClCH(OH)CH2Cl:
- This molecule also has a chiral center denoted by the asterisk (*) in the structural formula, which is the central carbon atom bonded to four different groups: Cl, H, O, Cl.
- Similar to the previous molecule, ClCH(OH)CH2Cl does not possess an internal plane of symmetry.
- Consequently, ClCH(OH)CH2Cl can have optical isomers.
In conclusion, the molecules that can have optical isomers out of the given options are H2NCH(CH3)COOH (choice b) and ClCH(OH)CH2Cl (choice c).