Appreciation that scientists have developed a range of analytical techniques which together enable the structures of new compounds to be confirmed.

Nuclear magnetic resonance (NMR) gives information about the position of ¹³C or ¹H atoms in a molecule.

¹³C NMR gives simpler spectra than 1H NMR.

The use of the δ scale for recording chemical shift.

Chemical shift depends on the molecular environment.

Integrated spectra indicate the relative numbers of ¹H atoms in different environments.

¹H NMR spectra are obtained using samples dissolved in deuterated solvents or CCl₄.

The use of tetramethylsilane (TMS) as a standard.

Students should be able to:

• explain why TMS is a suitable substance to use as a standard

• use ¹H NMR and ¹³C NMR spectra and chemical shift data from the Chemistry Data Booklet to suggest possible structures or part structures for molecules

• use integration data from 1H NMR spectra to determine the relative numbers of equivalent protons in the molecule

• use the n+1 rule to deduce the spin–spin splitting patterns of adjacent, non-equivalent protons, limited to doublet, triplet and quartet formation in aliphatic compounds.