3.3 Integration

3.3 Integration

• The first characteristic of every signal is chemical shift.
• The number of protons gives rise to the signal.
• The area under each signal is calculated by a computer and displayed as a numerical value under the signal.

• When compared to each other, these numbers have no meaning.

• A signal with an integration of 1.5 involves one and a half times as many protons as a signal with an integration of 1.
• If you want to arrive at whole numbers, you have to divide the numbers by two and get the same ratio in whole numbers.

• The signal at 2.4 ppm is equivalent to 2 equivalent protons, and the signal at 2.1 ppm is equivalent to 3 equivalent protons.

• The area under the signal is represented by the height of the step curves.
• A comparison of the heights of the four step curves shows a ratio of 2 to 3.

• The numbers are only relative when interpreting integration values.

• Butane has two different types of protons and will produce two different signals.
• The methylene groups give two signals.
• A computer analyzes the area under each signal and provides numbers that allow us to calculate a ratio.
• The exact number of protons is not indicated by this ratio.

• The exact numbers are 4 and 6 for the methylene groups.
• The exact number of protons giving rise to each signal can be determined by analyzing the NMR spectrum of an unknown compound.

• In order to give a total of 10 protons, the ratio of 2 : 3 must correspond with 4 protons and 6 protons.

• Symmetry can play an important role when considering integration values.

• The two methylene groups are equivalent to each other, and the two methyl groups are also equivalent to each other.
• The relative integration values of the two signals are 2 and 3.
• The values 2 and 3 are relative numbers.
• They represent 4 and 6 protons.
• The total of 10 protons in the compound can be determined by inspecting the formula.

• There is a compound with the formula C H O.

• There are three signals in the spectrum.
• Take the relative integration values and compare them to each other.

• Relative numbers are what this gives a ratio of.
• The number of protons in a compound is determined by the number of protons in the formula.
• The numbers 1 : 3 : 6 are the exact values.
• The values are sometimes expressed in the following way.

• There is a compound with the formula C H O.

• There is a compound with the formula C H O.