Interactive IR spectrum of methane |
Click on the peaks, labelled with red markers, to display the corresponding molecular vibration. | ||||
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The spectrum is extremely simple due both to the small number of bonds and the high symmetry of the molecule. Other vibrations, such as the 'breathing mode' in which all C-H bonds stretch together, do not change the dipole of the molecule: the molecule cannot absorb IR radiation to excite the vibration. |