- #1
Nick tringali
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In summary, the conversation discusses the concept of enantiomers and how it can be difficult to understand without visual aids. It is explained that flipping the molecule changes the position of the hydroxyl groups, making them enantiomers.
- #2
TeethWhitener
Science Advisor
Gold Member
- 2,622
- 2,232
Get a hold of a good molecular modeling kit or a visualization program (there are a few good free ones online). It’s a lot easier to wrap your head around stereoisomers when you can play with the 3D representations of molecules.
- #3
snorkack
- 2,190
- 477
No, they are not.Nick tringali said:
Even without getting a model - how can you flip them around one into another?
You cannot rotate it around horizontal axis - because this would flip the M-shaped carbon backbone into W. So the rotation which leaves the pentane backbone unchanged M would be the rotation around vertical axis.
But what happens to the hydroxyls then?
The upper form starts off having the left, say 2 hydroxyl group towards viewer and the right, then 4 hydroxyl group away from viewer.
When you flip the sheet, the 2-hydroxyl group will be on the right... but because you are now looking at it from the opposite side of sheet, it is now away from you. So you again have the left hydroxyl (now 4) towards you and the right hydroxyl away from you. The molecule is NOT converted to the form below where the left hydroxyl is away from you and right hydroxyl towards you.
Which is why they are enantiomers.
- #4
Mayhem
- 325
- 214
When you flip these mentally, you have to think of it as you are flipping a page of a book, not simply interchange the groups.
Related to I have no idea why this is an enantiomer
1. What is an enantiomer?
An enantiomer is a molecule that has the same chemical formula and connections between atoms as another molecule, but is a mirror image of that molecule. This means that the molecules are non-superimposable, or cannot be perfectly aligned with each other.
2. Why is it important to know if a molecule is an enantiomer?
Knowing if a molecule is an enantiomer is important because enantiomers can have different biological and chemical properties. This means that one enantiomer may have a different effect on the body or react differently in a chemical reaction compared to its mirror image. Therefore, it is important to be able to distinguish between enantiomers in order to understand their potential effects and uses.
3. How are enantiomers different from other types of isomers?
Enantiomers are a type of stereoisomer, meaning they have the same chemical formula and connections between atoms, but differ in their spatial arrangement. Other types of isomers, such as structural isomers, have the same chemical formula but differ in their atomic connectivity.
4. Can enantiomers have different physical properties?
Yes, enantiomers can have different physical properties such as melting point, boiling point, and solubility. This is because their mirror image arrangement can affect how they interact with other molecules.
5. How are enantiomers named and classified?
Enantiomers are named using the R/S system, which assigns a priority to the atoms connected to the chiral center of the molecule. The enantiomer with the highest priority group on the left side is designated as S (sinister) and the enantiomer with the highest priority group on the right side is designated as R (rectus). Enantiomers can also be classified as either D or L, based on their relation to the chiral center of the molecule to the D- or L-glyceraldehyde molecule.
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