Advanced Organic Chemistry: 1H NMR spectrum of chloroethane

SITEMAP * HOME PAGE * SEARCH * GCSE Level Chemistry age ~14-16 * Advanced Level Chemistry age ~16-19

The H-1 hydrogen-1 (proton) NMR spectrum of chloroethane

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 chloroethane

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

C2H5Cl CH3CH2Cl low and high resolution 1H proton nmr spectrum of chloroethane analysis interpretation of chemical shifts ppm spin spin line splitting diagram H1 H-1 nmr for ethyl chloride explaining spin-spin coupling for line splitting 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 resonances, called chemical shifts, are measured with respect to the TMS, and depend on the individual (electronic) chemical environment of the hydrogen atoms in an organic molecule - chloroethane here.

The chemical shifts quoted in ppm on the diagram of the H-1 NMR spectrum of chloroethane 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 chloroethane molecule.

chloroethane   CH3CH2Cl   CH3-CH2-Cl

Interpreting the H-1 NMR spectrum of chloroethane

In terms of spin-spin coupling from the possible proton magnetic orientations, for chloroethane I have only considered the interactions of non-equivalent protons on adjacent carbon atoms e.g. -CH2-CH3 protons etc.

For relatively simple molecules, the low resolution H-1 NMR spectrum of chloroethane is a good starting point (low/high resolution diagrams above).

The hydrogen atoms (protons) of chloroethane occupy 2 different chemical environments so that the low resolution NMR spectra should show 2 principal peaks of different H-1 NMR chemical shifts (diagram above for chloroethane).

CH3CH2Cl

Note the proton ratio 3:2 of the two colours of the protons in the two chemically different environments

Chemical shifts (a) to (b) on the H-1 NMR spectrum diagram for chloroethane.

Although there are 5 hydrogen atoms in the molecule, there are only 2 possible different chemical environments for the hydrogen atoms in chloroethane molecule.

The integrated signal proton ratio 3:2 observed in the high resolution H-1 NMR spectrum, corresponds with the structural formula of chloroethane.

The high resolution 1H NMR spectrum of chloroethane

All low and high resolution spectra of chloroethane show 2 groups of proton resonances and in the 3:2 ratio expected from the formula of chloroethane.

The ppm quoted on the diagram represent the peak of resonance intensity for a particular proton group in the molecule of chloroethane - 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 chloroethane below.

So, using the chemical shifts and applying the n+1 rule to chloroethane and make some predictions using some colour coding! (In problem solving you work the other way round!)

(a) 1H Chemical shift 1.49 ppm, CH3 protons: CH3CH2Cl

This 1H resonance is split by the CH2 protons into a 1:2:1 triplet (n+1 = 3)

Evidence for the presence of a CH2 group in the molecule of chloroethane

(b) 1H Chemical shift 3.51 ppm, CH2 protons: CH3CH2Cl

This 1H resonance is split by the CH3 protons into a 1:3:3:1 quartet (n+1 = 4)

Evidence for the presence of a CH3 group in the molecule of chloroethane

Note the increased effect on the 1H chemical shift of the protons on carbon atom nearest the most electronegative chlorine atom.

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: C2H5Cl CH3CH2Cl Interpreting the proton H-1 NMR spectra of chloroethane, low resolution & high resolution proton nmr spectra of chloroethane, H-1 nmr spectrum of chloroethane, understanding the hydrogen-1 nmr spectrum of chloroethane, explaining the line splitting patterns from spin-spin coupling  in the high resolution H-1 nmr spectra of chloroethane, revising the H-1 nmr spectrum of chloroethane, proton nmr of chloroethane, ppm chemical shifts of the H-1 nmr spectrum of chloroethane, 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 chloroethane, how to work out the number of chemically different protons in the structure of the chloroethane organic molecule, how to analyse the chemical shifts in the hydrogen-1 H-1 proton NMR spectrum of chloroethane using the n+1 rule to explain the spin - spin coupling ine splitting in the proton nmr spectrum of chloroethane deducing the nature of the protons from the chemical shifts ppm in the H-1 nmr spectrum of chloroethane examining the 1H nmr spectrum of  chloroethane analysing the 1-H nmr spectrum of chloroethane how do you sketch and interpret the H-1 NMR spectrum of chloroethane interpreting interpretation of the 1H proton spin-spin coupling causing line splitting in the NMR spectrum of chloroethane  assignment of chemical shifts in the proton 1H NMR spectrum of chloroethane formula explaining spin-spin coupling for line splitting of ethyl chloride

Links associated with chloroethane

The chemistry of HALOGENOALKANES (haloalkanes) 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

TOP OF PAGE