March 28, 2024, 10:08:31 AM
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Topic: Principal axis for the moment of inertia of 1,3,5-trimetoksybenzene  (Read 5510 times)

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Offline mir

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I have a descriptor called YZ-shadow, which is defines as the shadow projected from the YZ-plane in a molecule. YZ-plane is defined as the plane between the second most important and third most important principal axis for moment of inertia. For the molecule 1,3,5-trimetoksybenzene I can easily spot the first two important axis (the X-axis is coming out of the ring-plane, the Y axis is along one of the metoksygroups, as illustrated). But not the third one. Where is it? Any suggestions?

Btw - After some playing with a moleculeset I have found it harder to rotate the "Y-axis" as defined in the drawing. So the X-axis is probably the "Y-axis" and vice versa...
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Offline enahs

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You have a cyclohexane ring, it is not flat. Are you making a molecule and looking at it as a flat molecule, or are you using a conformation? If the question did not give you a conformation, tell your professor it was a poor question, or just assume it is chair.

Offline mir

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Its a benzene-ring :-)
And the conformation is correct. All of the metoxy-groups are in plane with the ring.

Its not my professor. Im doing a research into metoxy-methyl benzenes as a part of my thesis. And this molecule is very unique.
No single thing abides, but all things flow.
Fragment to fragment clings, and thus they grow
Until we know and name them.
Then by degrees they change and are no more
The things we know.
- Titus Lucretius Carus

http://www.ife.no

Offline enahs

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I am a tard and blind, what can I say.

Thinking of the right molecule, there is on obvious rotation-reflection primary axis, which would also have certain spectroscopic mojo, if that is what you are trying to account for?

Offline mir

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No-no, not spectroscopy. Its a descriptor from DFT-calculations and using the Codessa software. I am looking into some similarities between the HOMO-LUMO gap and the YZ-shadow indexes for this molecule. But the Codessa software doesn't tell me where the plane is going through. So I have to use logic. Which I am not very good in, because, I have only my molecule set.

If you are very interested I can send you the references to our publication when it is approved.
No single thing abides, but all things flow.
Fragment to fragment clings, and thus they grow
Until we know and name them.
Then by degrees they change and are no more
The things we know.
- Titus Lucretius Carus

http://www.ife.no

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