Linked Questions

5 votes
3 answers
6k views

Carbonyl bond vs alkene bond

Why are carbonyl bonds stronger than those of alkenes? I've read several times that carbonyl bonds are shorter and that you need to apply a higher amount of energy to break them. Why is that so? Is it ...
Αντώνιος Κελεσίδης's user avatar
7 votes
1 answer
780 views

What is the correct IUPAC nomenclature for this compound?

I recently came across this type of compound, and normally, I would follow the rules I've previously learnt, which is to find the longest carbon chain that contains the highest priority functional ...
GrandMasterIUPAC's user avatar
6 votes
2 answers
444 views

Why are excess nuclei required to produce an NMR signal?

In NMR, an excess population of nuclei is required to produce a signal. If saturation is achieved (same number of nuclei in the α and β states) no net signal can be produced. A signal is produced when ...
Eli Jones's user avatar
  • 2,020
0 votes
2 answers
808 views

Why doesn't 2,3-pentadiene show geometrical/cis-trans isomerism?

There are two different groups bonded to each terminal C in the C=C=C system, and there is restricted rotation about the C=C=C. So why doesn't it show cis-trans isomerism? The most common answer I get ...
user119212's user avatar
3 votes
1 answer
2k views

Periodic boundary conditions in DFT for cylindrical system

As I understand it, a DFT calculation uses periodic boundary conditions, whenever you want to simulate a bulk material. This is convenient because all information can then be extracted from the ...
user13514's user avatar
  • 151
11 votes
1 answer
261 views

How to apply the Cahn–Ingold–Prelog priority rules to an isotopically-labeled molecule?

Is the following the correct designation (S) for the chiral carbon in a skeletal representation of 1-chloro(3-13C)butan-2-amine? The CIP rules say to go one at a time by each rule until you find an ...
Parker Willett's user avatar
7 votes
2 answers
546 views

How much group representation theory is used in chemistry research?

I am a mathematician working in group theory and representation theory. When I try to explain these subjects to non-mathematicians, I often fail to provide a convincing reason to study these. So I am ...
Absol's user avatar
  • 181
4 votes
1 answer
2k views

Why do we observe signal coalescence during dynamic NMR?

At low temperature, the rotation around the N-C amide bond of dimethylformamide is slow, so the two methyl groups are in different chemical environments. The H NMR thus shows a peak for each of the ...
Max's user avatar
  • 1,026
3 votes
0 answers
3k views

What is the correct order of Relative Inductive Effect (-I) of different groups?

This confusion has put me in problem several times since last 2 years and I have been looking for a clarification but it seems that answer depends upon who you ask. I have several examples where I ...
Ritanshu's user avatar
  • 189
3 votes
1 answer
2k views

Shouldn't this compound be called 2-methyl-5-(1,2-dimethylpropyl)nonane?

The book says that the name should have dimethylpropyl methyl nonane in that order. Shouldn't the methyl group come first since methyl comes before methylpropyl (in the alphabetic order)? Our prof ...
Jon's user avatar
  • 41
0 votes
1 answer
947 views

How do you find oxidation state of the metals of a complex with two coordination spheres?

For example suppose we have $\ce{[Pt(NH3)4][PtCl4]}.$ For the naming of this complex I need to know the oxidation number of the metals; let the oxidation number of first and second $\ce{Pt}$ be $x, y$...
Osmium's user avatar
  • 222
2 votes
2 answers
396 views

How are there three possible tautomers of 2,2,4-trimethylheptane-3,5-dione? [closed]

The answer for the above question is three. But I am able to draw four structures: Where am I getting it wrong?
Garima Singh's user avatar
7 votes
1 answer
506 views

What is the correct approach to obtain PES using CASSCF?

I am new to CASSCF. I want to draw a PES for the ground state and the first excited sate of methyl amine for learning purpose. I want to verify if I am correct using the correct approach. Do a ...
Chemist's user avatar
  • 343
3 votes
3 answers
580 views

How can a 90 degree pulse cause precession perpendicular to the applied field in proton NMR

From my understanding, a proton's magnetic moment in an NMR experiment can undergo precession in only two discrete states: either parallel to the applied magnetic field, or antiparallel to it. ...
John John-man's user avatar
0 votes
1 answer
724 views

Will group 2 chlorides dissolve in water in water or react to produce distinct products? How does this differ by the type of salt? [closed]

I thought it'd dissolve... but am i wrong? I added calcium chloride to water, and it was smoking, i was so confused. Can someone explain happened? I am doing an experiment where i dissolve salts in ...
Raze XIX's user avatar

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