PC211 IR spectroscopy

IR energy causes the bonds to

• dissociate

• doesn't affect bonds

• vibrate

Bending vibration appears

• higher than 1400cm^-1

• lower than 1400cm^-1

• higher than 3000cm^-1

Compounds absorb IR energy if

• the bonds are symmetrical

• there is a difference in electronegativity (polar)

The higher the Strength of the bond

• the higher the frequency of vibration

• the lower the frequency of vibration

The lighter the mass of atoms connected to the bond

• the higher the frequency of vibration

• the lower the frequency of vibration