Advanced Organic Chemistry: Carbon-13 NMR spectrum of 2-methylpropene (CH3)2C=CH2

Interpreting and explaining the 13C NMR spectrum: 2-methylpropene (2-methylprop-1-ene)

[Author © Dr Phil Brown PhD: Doc Brown's advanced level organic chemistry exam revision notes suitable for students of UK A level chemistry courses & US K12 grade 11, grade 12 and AP honors chemistry courses: Molecular spectroscopy - analysing the 13C NMR spectra of methylpropene, 2-methylpropene [spectra page updated April 4th 2026 *]

 email doc brown Re-edit the 13C NMR spectrum of H2C=C(CH3)2

 Links associated with 2-methylpropene

 This is a BIG chemistry website, PLEASE take time to explore it

 C-13 NMR spectroscopy - spectra index  *  [privacy policy, cookies and disclaimer]

Introductory note on the 13C NMR spectrum of 2-methylpropene

Students and teachers please note that my explanation of the carbon-13 NMR spectrum of 2-methylpropene is designed for advanced, but pre-university, chemistry courses.

The description does not involve the chemical shift δ spin-spin coupling effects for 2-methylpropene and the relative size of the carbon-13 NMR shifts does not give the ratio of the carbon atoms in the different non-equivalent chemical environments of the 2-methylpropene molecule.

The most common solvent used for investigating the 13C NMR spectrum of compounds like 2-methylpropene, is CDCl3 and other deuterated solvents.

13C nmr spectrum of 2-methylpropene C4H8 (CH3)2C=CH2 analysis of chemical shifts ppm interpretation of C-13 chemical shifts ppm of 2-methylprop-1-ene C13 carbon-13 nmr doc brown's advanced organic chemistry revision notes 

TMS is the acronym for tetramethylsilane, formula Si(CH3)4, whose 13C atoms are arbitrarily given a chemical shift of 0.0 ppm. This is the 'standard' in 13C NMR spectroscopy and all other 13C resonances, called chemical shifts, are measured with respect to the TMS, and depend on the individual (electronic) chemical environment of the 13C atoms in an organic molecule - 2-methylpropene here.

2-methylpropene, alkenes structure and naming (c) doc b, alkenes structure and naming (c) doc b, alkenes structure and naming (c) doc b , skeletal formula of methylpropene 2-methylpropene advanced organic chemistry

The molecular structure and naming of alkenes

Interpreting the C-13 NMR spectrum of 2-methylpropene

As you can see from the diagram above there are 3 different 13C chemical shift lines in the C-13 NMR spectrum of 2-methylpropene indicating 3 different chemical environments of the 4 carbon atoms of 2-methylpropene.

(CH3)2C=CH2

(Note the 3 different colours indicating the 3 different chemical environments of the 4 carbon atoms in 2-methylpropene).

13C chemical shifts δ (a) to (c) on the C-13 NMR spectrum diagram for 2-methylpropene.

(a)  (CH3)2C=CH2 : 13C NMR chemical shift δ of 24 ppm for the methyl group carbon atoms.

The two methyl group carbon atoms are equivalent to each other, giving the same 13C NMR chemical shift.

(b)  (CH3)2C=CH2 : 13C NMR chemical shift δ of 142 ppm for the 'left' C=C carbon atom.

(c)  (CH3)2C=CH2 : 13C NMR chemical shift δ of 112 ppm for the 'right' =CH2 carbon atom of the CC double bond..

The carbon-13 NMR spectra provides direct evidence of 3 different carbon atom chemical environments for the 4 carbon atoms in the 2-methylpropene molecule, deduced from the presence of 3 different 13C NMR chemical shifts (ppm).

Key words & phrases: isomer of molecular formula C4H8 (CH3)2C=CH2 Interpreting the C-13 NMR spectra of 2-methylpropene, 13C nmr spectrum of 2-methylpropene, understanding the carbon-13 nmr spectrum of 2-methylpropene, explaining the line pattern in the high resolution C-13 nmr spectra of 2-methylpropene, revising the C-13 nmr spectrum of 2-methylpropene, ppm chemical shifts of the C-13 nmr spectrum of 2-methylpropene, how to construct the diagram of the C-13 nmr spectrum of 2-methylpropene, how to analyse the chemical shifts in the carbon-13 NMR spectrum of 2-methylpropene deducing the chemical environment of all the carbon atoms in 2-methylpropene examining the c13 nmr spectrum of  2-methylpropene analysing the 13C nmr spectrum of 2-methylpropene how do you sketch and interpret the C-13 NMR spectrum of 2-methylpropene interpreting interpretation of the C-13 NMR spectrum of 2-methylpropene assignment of chemical shifts in the 13C NMR spectrum of alkene functional group 2-methylpropene 2-Methylprop-1-ene methylpropene isobutene isobutylene 2-methylpropylene How do you interpret the chemical shifts of the C-13 NMR spectrum of 2-methylpropene How to interpret the C-13 NMR spectrum of 2-methylpropene Explanatory diagram of the 13C C-13 carbon-13 NMR spectrum of the  number of different carbon atom environments in the 2-methylpropene molecule from its carbon-13 NMR spectrum to help work out the molecular structure of the 2-methylpropene molecule? The uses and distinctive features of the carbon-13 NMR spectrum of the 2-methylpropene molecule explained. What do the number and values of the chemical shifts from the c-13 carbon-13 NMR spectrum tell us about the 2-methylpropene molecule? explaining the decoupled carbon-13 NMR spectrum of 2-methylpropene  with a detailed interpretation diagram of all the C-13 chemical shifts and intensities

Links associated with 2-methylpropene

The chemistry of ALKENES revision notes INDEX

The infrared spectrum of 2-methylpropene (2-methylprop-1-ene)

The mass spectrum of 2-methylpropene (2-methylprop-1-ene)

The H-1 NMR spectrum of 2-methylpropene (2-methylprop-1-ene)

C-13 NMR spectroscopy index

ALL SPECTROSCOPY INDEXES

All Advanced Organic Chemistry Notes

Use My Google search site box

Email doc b: chem55555@hotmail.com

Website content © Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of Doc Brown's pre-university advanced level chemistry website material is NOT permitted. Exam revision summaries & references to science course specifications are unofficial. These organic chemistry revision notes on spectroscopy (13C NMR spectra of methylpropene, 2-methylpropene) are suitable for use of pre-university students studying AQA advanced level chemistry, Edexcel advanced level chemistry, OCR advanced level chemistry, IB advanced level chemistry, WJEC (Eduqas) advanced level chemistry, CIE advanced level chemistry, CCEA advanced level chemistry, US grade 11-12 AP honors chemistry courses and they will also prove useful to 1st year undergraduate students of chemistry.

TOP OF PAGE