What is true regarding a meso form of a compound?a)A meso form is achi...
Explanation: The given compound is superimposable on its mirror image, so it is achiral. Achiral molecules which have chirality centers are called meso compounds. Meso compounds are possible if two (or more) chirality centers in a molecule have the same set of four substituents.
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What is true regarding a meso form of a compound?a)A meso form is achi...
The given compound is superimposable on its mirror image, so it is achiral. Achiral molecules which have chirality centers are called meso compounds. Meso compounds are possible if two (or more) chirality centers in a molecule have the same set of four substituents.
What is true regarding a meso form of a compound?a)A meso form is achi...
A meso form is achiral due to internal compensation of optical rotation.
A meso compound is a type of stereoisomer that possesses an internal plane of symmetry, which results in the compound being achiral. This means that it does not exhibit optical activity and cannot be separated into its enantiomers. Here is a detailed explanation of why option D is the correct answer:
Definition of a meso compound:
- A meso compound is a molecule that contains chiral centers but is overall achiral due to the presence of an internal plane of symmetry.
- It has mirror symmetry, meaning that it can be divided into two halves that are mirror images of each other.
Mechanism of optical activity:
- Optical activity is the ability of a compound to rotate the plane of polarized light.
- Chiral compounds, which lack any internal symmetry, exhibit optical activity because their enantiomers rotate polarized light in opposite directions.
- In contrast, achiral compounds do not have this ability and do not exhibit optical activity.
Internal compensation of optical rotation:
- In a meso compound, although individual chiral centers exist, the molecule as a whole is achiral because of the presence of an internal plane of symmetry.
- This internal symmetry causes the two halves of the molecule to rotate polarized light in opposite directions but to the same extent.
- As a result, the optical rotations cancel each other out, and the compound as a whole does not exhibit any net optical activity.
- This internal compensation of optical rotation is the key characteristic of a meso compound.
Consequences of meso form:
- Due to their achiral nature, meso compounds cannot be separated into their enantiomers by traditional methods such as fractional crystallization or chromatography.
- The presence of an axis of symmetry allows for the internal compensation of optical rotation, making the meso form optically inactive.
- This lack of optical activity makes it difficult to distinguish between the two enantiomers and isolating the meso form from its optically active stereoisomers.
In conclusion, a meso form of a compound is achiral due to the presence of an internal plane of symmetry, which leads to the internal compensation of optical rotation. This characteristic makes meso compounds optically inactive and prevents their separation from their optically active stereoisomers.
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