Find Symmetry in Molecules: NMR Spectra & 3D Structures

  • Thread starter Thread starter Big-Daddy
  • Start date Start date
  • Tags Tags
    Molecules Symmetry
AI Thread Summary
To find symmetry in molecules for identifying equivalent nuclei in NMR spectra, understanding point group symmetry is essential. This involves recognizing the symmetrical properties of molecules, which can be challenging, especially with larger structures represented in 2D. Resources like "Molecular Symmetry and Spectroscopy" by Bunker and Jensen are recommended for a thorough understanding, as they provide exercises and insights into group theory relevant to spectroscopy. For a more accessible overview, chapter 12 of "Physical Chemistry: A Molecular Approach" by D. A. McQuarrie is suggested for undergraduate learners. These materials can help bridge the gap between theoretical concepts and practical applications in NMR spectroscopy.
Big-Daddy
Messages
333
Reaction score
1
What is the general method for finding symmetry in molecules which would allow you to find which nuclei are equivalent in an NMR spectrum?

I know it sounds vague but it seems inevitable. Any good guides on the Internet would be great. My main issue is with larger molecules whose structures are drawn in 2D, and virtually any 3D structure (e.g. adamantane).
 
Chemistry news on Phys.org
Are you familiar with the idea of point group symmetry?
 
No. And looking it up leads to a list of mathematical symbols that I cannot hope to understand on my own.
 
Personally I think the proper way to learn group theory, especially with hindsight of spectroscopic applications like NMR, is to start from the CNPI group. The classic book on that topic, with many exercises is Bunker and Jensen, Molecular Symmetry and Spectroscopy.
See also
http://www.ptc.uni-wuppertal.de/team/hochschullehrer/prof-per-jensen-phd.html
 
Last edited by a moderator:
I fully agree with DrDu recommendation. That book is comprehensive and avilable from Dover Publication with a reasonable price.
But for a quick and easy to follow overview on the undergraduate level, you can consult chapter 12 in D. A. McQuarrie "physical chemistry a molecular approach."
 
It seems like a simple enough question: what is the solubility of epsom salt in water at 20°C? A graph or table showing how it varies with temperature would be a bonus. But upon searching the internet I have been unable to determine this with confidence. Wikipedia gives the value of 113g/100ml. But other sources disagree and I can't find a definitive source for the information. I even asked chatgpt but it couldn't be sure either. I thought, naively, that this would be easy to look up without...
I was introduced to the Octet Rule recently and make me wonder, why does 8 valence electrons or a full p orbital always make an element inert? What is so special with a full p orbital? Like take Calcium for an example, its outer orbital is filled but its only the s orbital thats filled so its still reactive not so much as the Alkaline metals but still pretty reactive. Can someone explain it to me? Thanks!!
Back
Top