All Questions
17
questions
21
votes
1
answer
7k
views
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 ...
- 6,795
17
votes
1
answer
521
views
Are chiral quasicrystals possible?
Quasicrystals are materials that have long-range atomic order but lack the translational symmetry of conventional crystals. All quasicrystalline tilings and packings I have read about thus far, whilst ...
- 10.9k
7
votes
2
answers
11k
views
Does an axis of symmetry determine chiralty?
What I've understood about chirality and elements of symmetry:
A molecule that is not superposable on its mirror image is said to be chiral.
Plane of symmetry:
An imaginary plane cutting a compound ...
- 177
6
votes
1
answer
361
views
Use of axis of symmetry
Does an axis of symmetry determine chiralty?
Is axis of symmetry considered a true symmetry?
From the above two links, I read that a compound having axis /alternating axis of symmetry is NOT ...
- 1,027
5
votes
2
answers
1k
views
Link between centrosymmetry, dipole moment and chirality
What is the relationship between the three concepts in the title?
I know all centrosymmetric molecules are achiral, but not all achiral molecules are centrosymmetric. Thus, there are no molecules ...
- 41.2k
4
votes
2
answers
11k
views
Is trans-1,2-dimethylcyclobutane chiral?
If we look at its mirror image about a mirror which is perpendicular to plane of the molecule, the two $\ce{-CH3}$ groups which are pointing upwards and downwards (implied by the wedge and the dash) ...
- 2,153
4
votes
2
answers
248
views
Is there any mathematical or logical proof that carbon with 4 different groups would be chiral?
In chemistry; chirality is generally defined in 2 ways.
Lord Kelvin's definition: "I call any geometrical figure, or group of points, chiral, and say it has chirality, if its image in a plane ...
user36001
3
votes
1
answer
2k
views
Example of an achiral molecule without a plane of symmetry or inversion center?
Some websites, such as this textbook, mention how generally a plane of symmetry or inversion center in a molecule is enough to consider it achiral. Nonetheless, this source clarifies
but if these ...
- 271
3
votes
2
answers
458
views
Enantiomer or not?
My professor said that this compound is an enantiomer but I think it has a plane of symmetry and has no chiral carbons. Am I missing something ?
- 567
3
votes
0
answers
137
views
Why does an improper rotation axis preclude chirality?
Can anybody prove that any molecule with an axis of improper rotation is nonchiral? I still do not understand why this is so, any proper mathematical proof or visualisation of a generalised molecule ...
- 39
1
vote
1
answer
6k
views
How are these molecules chiral and achiral?
I always thought that a molecule couldn't be chiral if it had a plane of symmetry. Doesn't the chiral molecule here have symmetry diagonally across the OHs?
The achiral one doesn't look symmetrical ...
- 29
1
vote
1
answer
314
views
Do we need to check for all kinds of symmetry in a compound to declare it achiral?
I know that a compound is achiral if it contains any one of the following kind of symmetry.
1.Plane of symmetry
2.Centre of symmetry
3.Normal axis of symmetry
4.Alternate axis of symmetry
It is ...
user92687
0
votes
1
answer
276
views
Of 2-bromobutan-2-ol and trans-1,2-dimethylcyclobutane which is chiral as well as dissymmetric?
In an examination I was asked to determine the molecules which are chiral as well as dissymmetric. There were four options, and among them, two were achiral, as they had an improper axis of symmetry. ...
- 371
0
votes
1
answer
560
views
Are there optically active molecules in which all atoms lie in the same plane?
I've learnt that when a molecule is non-superposable on its mirror image, it exists as a pair of enantiomers and is optically active. Absence of plane of symmetry is given to be one of the properties ...
- 2,090
0
votes
2
answers
265
views
Is plane of symmetry a necessary and sufficient condition for optical inactivity in coordination compounds? [closed]
In organic chemistry, we have to check for all three types of symmetry in a compound to check its chirality, ie, plane, alternate axis and centre of symmetry. But in coordination compounds, do we need ...
user92687