Questions tagged [stereochemistry]
Applicable to questions about the spatial arrangement of atoms in a molecule and how they affect its physical or chemical properties.
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What is Bent's rule?
I'm all bent out of shape trying to figure out what Bent's rule means. I have several formulations of it, and the most common formulation is also the hardest to understand.
Atomic s character ...
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Molecular chirality and optical rotation
Why does having molecular chirality result in optical rotation? The dissymetry or chirality of molecules translates to the rotation of plane polarized light, the magnitude and direction depending on ...
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Utility of Bent's Rule - What can Bent's rule explain that other qualitative considerations cannot?
Does Bent's rule have any utility? I got a vehement earful for "NO." Points raised by my professor:
Coulombic considerations can be used to rationalize bond angles, strengths, and lengths without ...
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Why is the inversion barrier larger in PH3 than it is in NH3?
The inversion barrier in $\ce{NH3}$ is approximately $5~\mathrm{kcal~mol^{-1}}$ and that of $\ce{PH3}$ is $35~\mathrm{kcal~mol^{-1}}$. This has well-known stereochemical consequences in that amines ...
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Why is 1-ethylidene-4-methylcyclohexane chiral?
As far as I can tell, there doesn't seem to be a chiral carbon in the compound, 1-ethylidene-4-methylcyclohexane. The C-4 of the cyclohexane ring has two groups with exactly the same connectivity, and ...
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What are the CIP rules for cyclic substituents?
Here's what I read on Wikipedia (section "Cycles"):
To handle a molecule containing one or more cycles, one must first expand it into a tree (called a hierarchical digraph by the authors) by ...
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Twisting stereoisomers with rings to determine R/S [closed]
I know that if the smallest atomic number group is not in the back, we can twist the molecule so that it is in the back and then determine if it is R/S (Left image). But if the chiral center is ...
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Can heteroatoms with lone pairs be chiral centres?
If a compound has a carbon atom with four different groups covalently bonded to it, it is called asymmetric and enantiomers of the compound can exist.
But imagine if one has a different central atom, ...
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Is cis-1,2-dimethylcyclohexane a meso compound?
I was watching a video lecture today on hydrocarbons and came across this. The instructor says that, as there is a plane of symmetry, cis-1,2-dimethylcyclohexane is a meso-compound:
However, the ...
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Why are allenes chiral?
How is 1-bromo-3-chloropropa-1,2-diene ($\ce{BrHC=C=CHCl}$) chiral? It doesn't have any carbon that is connected to four different groups.
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IUPAC name for 1,2,3-trichlorocyclopropane?
What is the IUPAC name for the two isomers of 1,2,3-trichlorocyclopropane? Similarly what is the name for isomers of 1,2,3,4-tetrachlorocyclobutane, 1,2,3,4,5-pentachlorocyclopentane, etc?
1,2,3-...
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Dihedral angle of gaseous and crystalline HOOH
Why does hydrogen peroxide exhibit a dihedral angle of $111.5^\circ$ in the gaseous state? And a dihedral angle of $90.2^\circ$ in the crystalline phase?
I know that in general, there is likely to be ...
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Is (2R,3S)-butane-2,3-diol chiral?
Is the attached compound a chiral or achiral overall? My lecturer said that this is an achiral compound because it has a superposable mirror image but I don't get that. So I tried to figure out the ...
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How to assign E/Z configuration according to the Cahn-Ingold-Prelog rules when subsituents differ only by stereochemistry
I stumbled-upon this compound:
I'm wondering how to determine the configuration of the double bond. Is it E or Z? How do I decide on the priorities when the substituents can only differ in the ...
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What is the difference between D and L configuration, and + and −?
What is the difference between D and L configuration, and + and −?
My textbook says they are two different things.
It also says that the correct way to name glucose is D(+)-glucose.
Could someone ...
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