2.A Absorption spectroscopy

Absorption spectroscopy measures absorption of radiation as a function of frequency/wavelength (they are inversely proportional), as a result of its interaction with a sample.

2.A.1 Infrared region

The infrared region is below red in the electromagnetic spectrum:

2.A.1.a intramolecular vibrations and rotations

2.A.1.b recognizing common characteristic group absorptions, fingerprint region

2.A.2 Visible region

2.A.2.a absorption in visible region yielding complementary color

2.A.2.b effect of structural changes on absorption

2.A.3 Ultraviolet region

2.A.3.a -electron and nonbonding electron transitions

2.A.3.b conjugated systems