Environments for hydrogen
The number of signals in the 1H NMR spectrum depends on the number of different environments for hydrogen. The principles for predicting the number of different environments for 1H are summarised below.
Hydrogens bonded to the same carbon
Hydrogens bonded to different carbons are in the same environment
The number of environments for hydrogen does not necessarily equal the number of environments for carbon because some carbons do not bear any hydrogens.
Hydrogens bonded to the same carbonare in the same environment.
There are five different environments for 2-chloropentane.
There are five different signals in the 1H NMR spectrum, ignoring splitting (see later).
There are five different signals in the 1H NMR spectrum, ignoring splitting (see later).
Hydrogens bonded to different carbons are in the same environment if the carbons are in the same environment.
There are three different environments for 3-chloropentane.
There are three different signals in the 1H NMR spectrum, ignoring splitting (see later).
There are three different signals in the 1H NMR spectrum, ignoring splitting (see later).
The number of environments for hydrogen does not necessarily equal the number of environments for carbon because some carbons do not bear any hydrogens.