Questions tagged [symmetry]
The description of the symmetry present in molecules. Molecular symmetry is useful for explaining or predicting of a molecule's chemical properties.
254
questions
2
votes
1
answer
405
views
What is m.2m point group?
I'm using Bilbao Crystallographic Server to find 3D crystallographic point groups of the K points of anatase TiO2.
Since the space group of anatse TiO2 is $I4_1/amd$, on this page, I found the point ...
- 273
3
votes
2
answers
388
views
Determination of energies in MO diagrams
How do we determine the relative placements of molecular orbitals in their diagrams? I understand that we can use point groups to find symmetry-allowed interactions between orbitals that we write on ...
1
vote
1
answer
1k
views
is this compound meso? trans-1,4 dimethylcyclohexane [duplicate]
I had a question on a quiz that asked if the compound below was meso or not. I thought that it would be meso because there is a plane of symmetry going through the two methyls, but the answer was that ...
- 49
3
votes
1
answer
1k
views
How do we find the SALCs?
I am trying to understand exactly what IRREPs are and, in order to know more about it, I started reading the chem.libretext course on molecular symmetry which up to this point seemed fairly ...
- 131
5
votes
1
answer
518
views
What does it mean by non-bonding p pi orbital?
In a paper by Peng et. al.,[1] I read about the valence band maximum of $\ce{TiO2}$ consists of non-bonding O pπ orbitals
... the valence band maximum (VBM) consists of non-bonding O pπ states
What ...
- 273
6
votes
2
answers
2k
views
Why are there only 14 types of Bravais lattices and not 28 when there are 7 types of unit cells and each can have four variations?
As the title suggests, I can't understand why certain kinds of variations (like Face-centred or Body-centred) are restricted to certain types of unit cells. An orthorhombic unit cell has Primitive, ...
- 317
0
votes
1
answer
272
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
7
votes
1
answer
154
views
Why does twistronic 'magic angle' graphene have only 180-degree symmetry?
From Graphene superconductors may be less exotic than physicists hoped[1]:
Excitement rose earlier this year with the discovery of
superconductivity in a similar
system[2]:
three layers of graphene ...
- 1,795
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
0
votes
1
answer
582
views
d orbital irreducible representations in metal in ML4 model [closed]
In ML4 (Metal—4 ligands)model which has a square planar shape and D4h point group, what is the irreducible representation for the 5 kinds of d orbitals in the central metal?
10
votes
0
answers
141
views
Using symmetry and group theory arguments to explain iron(II) in a tetrahedral crystal field
I am trying to figure out how to explain $1s \rightarrow 3d$ spectroscopic transitions for $\ce{Fe^{2+}}$ in $T_\mathrm{d}$ symmetry. These transitions make up the pre-edge region in K edge X-ray ...
- 101
1
vote
0
answers
92
views
High symmetry points and x-coordinates
Is it possible to work out the x-coordinates related to high symmetry points?
The software I'm using doesn't provide me with that, so I was wondering if there is a way to manually figure it out, as I ...
- 11
0
votes
0
answers
444
views
How many stereoisomers are present in octahedral complexes of type MA3B2C?
Does $\ce{MA3B2C}$ type have optical isomerism or just geometric isomerism? I was told that it has three isomers, two cis and one trans. Are the two cis isomers optically active?
1
vote
0
answers
583
views
D-orbitals of point group C2v
I'm trying to construct an MO diagram for cisplatin, which has C2v symmetry. However, there is no Mulliken label for the d(x^2-y^2) orbital in the character table. Does this orbital not form molecular ...
- 21
1
vote
0
answers
18
views
Why does hydrogenation of this compound not result in a diastereomeric mixture? [duplicate]
In a question, this compound was given and it was asked:
"Hydrogenation of the above compound in the presence of poisoned Palladium catalyst gives?"
When I was answering it, I thought that ...
- 119