7. Infrared Spectroscopy Flashcards
(7 cards)
What does IR spectroscopy show?
The bending and stretching (vibrations) of covalent bonds.
How are the bonds picked up?
They absorb energy in the IR region of the electromagnetic spectrum, and the wavelength absorbed depends on the bond.
What runs along the horizontal axis of an IR spectrum?
Wavenumber (cm-1️⃣)
1 divided by the wavelength in cm
How far does the horizontal axis run?
Left to right, 4000cm-1️⃣ to 400cm-1️⃣
What runs along the vertical axis of an IR spectrum?
% transmittance, so the graph shows dips down from 100%
How are the peaks significant?
They indicate the presence of a particular bond or functional group
What is the fingerprint region?
Between 500 and 1300cm-1️⃣. It is specific to any particular molecule.