HOME PAGE * KS3 SCIENCES * GCSE BIOLOGY CHEMISTRY PHYSICS * ADVANCED LEVEL CHEMISTRY

SPECTROSCOPY INDEXES  *  All Advanced Organic Chemistry Notes  *  [SEARCH BOX]

Advanced Organic Chemistry: H-1 NMR spectrum of 1,3,5-trimethylbenzene (mesitylene)

Scroll down and take time to study the content and/or follow links or [Use the website search box]

The H-1 hydrogen-1 (proton) NMR spectrum of 1,3,5-trimethylbenzene (mesitylene)

Doc Brown's Chemistry Advanced Level Pre-University Chemistry Revision Study Notes for UK IB KS5 A/AS GCE advanced A level organic chemistry students US K12 grade 11 grade 12 organic chemistry courses involving molecular spectroscopy analysing H-1 NMR spectra of 1,3,5-trimethylbenzene (mesitylene)

email doc brown

Use your mobile phone or ipad etc. in 'landscape' mode

This is a BIG website, you need to take time to explore it

H-1 proton NMR spectroscopy - spectra index

C9H12 low and high resolution H-1 proton nmr spectrum of 1,3,5-trimethylbenzene (mesitylene) analysis interpretation of chemical shifts ppm spin spin line splitting diagram H1 1-H nmr for 1,3,5-trimethylbenzene (mesitylene) doc brown's advanced organic chemistry revision notes

TMS is the acronym for tetramethylsilane, formula Si(CH3)4, whose protons are arbitrarily given a chemical shift of 0.0 ppm. This is the 'standard' in 1H NMR spectroscopy and all other proton shifts, called chemical shifts, depend on the individual (electronic) chemical environment of the hydrogen atoms in an organic molecule - 1,3,5-trimethylbenzene (mesitylene) here.

The chemical shifts quoted in ppm on the diagram of the H-1 NMR spectrum of 1,3,5-trimethylbenzene (mesitylene) represent the peaks of the intensity of the chemical shifts of (which are often groups of split lines at high resolution) AND the relative integrated areas under the peaks gives you the ratio of protons in the different chemical environments of the 1,3,5-trimethylbenzene (mesitylene) molecule.

structural formula 1,3,5-trimethylbenzene mesitylene molecular structure molecular formula C9H12 C6H3(CH3)3

Interpreting the H-1 NMR spectrum of 1,3,5-trimethylbenzene (mesitylene)

Because of the symmetry of the molecule, the hydrogen atoms (protons) of 1,3,5-trimethylbenzene (mesitylene) can only occupy 2 different chemical environments so that the low/high resolution NMR spectra should show 2 peaks of different H-1 NMR chemical shifts (diagram above for 1,3,5-trimethylbenzene (mesitylene)).

Although there are 12 hydrogen atoms in the molecule, there are only 2 possible different chemical environments for the hydrogen atoms in 1,3,5-trimethylbenzene (mesitylene) molecule - a very symmetrical molecule.

The integrated signal proton ratio 1:3 observed in the high resolution H-1 NMR spectrum, corresponds with the structural formula of 1,3,5-trimethylbenzene (mesitylene) in terms of the aryl:alkyl protons.

The high resolution H-1 NMR spectrum of 1,3,5-trimethylbenzene (mesitylene)

The ppm quoted on the diagram represent the peak of resonance intensity for a particular proton group in the molecule of 1,3,5-trimethylbenzene (mesitylene) - since the peak' is at the apex of a band of H-1 NMR resonances due to spin - spin coupling field splitting effects - see high resolution notes on 1,3,5-trimethylbenzene (mesitylene) below.

(a) 1H Chemical shift 6.78 ppm resonance from the benzene ring protons.

All four aromatic protons are equivalent and no significant splitting observed

(b) 1H Chemical shift 2.26 ppm from the methyl protons.

All six alkyl protons are equivalent and no significant splitting observed

What you get from the spectrum is a ratio of 1:3 (actually 3:9) for aryl:alkyl protons in 1,3,5-trimethylbenzene.


Number of directly adjacent protons 1H causing splitting Splitting pattern produced from the n+1 rule on spin-spin coupling and the theoretical ratio of line intensities
0 means no splitting             1            
1 creates a doublet           1   1          
2 creates a triplet         1   2   1        
3 creates a quartet       1   3   3   1      
4 creates a quintet     1   4   6   4   1    
5 creates a sextet   1   5   10   10   5   1  
6 creates a septet 1   6   15   20   15   6   1

Key words & phrases: C9H12 C6H3(CH3)3 Interpreting the proton H-1 NMR spectra of 1,3,5-trimethylbenzene (mesitylene), low resolution & high resolution proton nmr spectra of 1,3,5-trimethylbenzene (mesitylene), H-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene), understanding the hydrogen-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene), explaining the line splitting patterns in the high resolution H-1 nmr spectra of 1,3,5-trimethylbenzene (mesitylene), revising the H-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene), proton nmr of 1,3,5-trimethylbenzene (mesitylene), ppm chemical shifts of the H-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene), explaining and analyzing spin spin line splitting in the H-1 nmr spectrum, how to construct the diagram of the H-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene), how to work out the number of chemically different protons in the structure of the 1,3,5-trimethylbenzene (mesitylene) organic molecule, how to analyse the chemical shifts in the hydrogen-1 H-1 proton NMR spectrum of 1,3,5-trimethylbenzene (mesitylene) using the n+1 rule to explain the spin - spin coupling ine splitting in the proton nmr spectrum of 1,3,5-trimethylbenzene (mesitylene) deducing the nature of the protons from the chemical shifts ppm in the H-1 nmr spectrum of 1,3,5-trimethylbenzene (mesitylene) examining the 1H nmr spectrum of  1,3,5-trimethylbenzene (mesitylene) analysing the 1-H nmr spectrum of 1,3,5-trimethylbenzene (mesitylene) how do you sketch and interpret the H-1 NMR spectrum of 1,3,5-trimethylbenzene (mesitylene) interpreting interpretation of the H-1 proton NMR spectrum of 1,3,5-trimethylbenzene (mesitylene)


Links associated with 1,3,5-trimethylbenzene (mesitylene)

The chemistry of AROMATIC COMPOUNDS revision notes INDEX

H-1 proton NMR spectroscopy index  (Please read 8 points at the top of the 1H NMR index page)

ALL SPECTROSCOPY INDEXES

All Advanced Organic Chemistry Notes

Use My Google search site box

Email doc b: chem55555@hotmail.com

 Doc Brown's Chemistry 

*

TOP OF PAGE