The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source such as SIRI, and follow its directions. MSDS for aniline is available at Mallinckrodt Baker.
Aniline is a benzenoid compound. The NH2 group attached to the benzene ring means that there is a lone pair of electrons that can enter into conjugation with the benzene ring resulting in delocalization in the aniline.
Aniline absorbs in the K (220 - 250 nm) and the B (250 - 290 nm) bands exhibited by benzenoid compounds. The K and B bands arise from π to π* transitions as a result of the a group containing multiple bond being attached to the benzene ring. When dissolved in ethanol, λmax for aniline is 230 nm, but in dilute aqueous acid λmax is 203 nm. In the latter case the anilinium cation is formed and the lone pair is no longer available for conjugation with the benzene ring. Consequently, the absorption of the molecule shifts to the lower λmax value and behaves like benzene.
^Lange's Handbook of Chemistry, 10th ed. pp 1234-1237
^Lange's Handbook of Chemistry, 10th ed. pp 1661-1663
^Lange's Handbook of Chemistry, 10th ed. pp 1669-1674
^ ab Pure Component Properties (Queriable database). Chemical Engineering Research Information Center. Retrieved on 28 May 2007.
^Lange's Handbook of Chemistry, 10th ed, pp 1522-1524
^ ab Binary Vapor-Liquid Equilibrium Data (Queriable database). Chemical Engineering Research Information Center. Retrieved on 6 June 2007.
^ [http://www.aist.go.jp/RIODB/SDBS/cgi-bin/cre_index.cgi Spectral Database for
Organic Compounds] (Queriable database). Advanced Industrial Science and Technology. Retrieved on 9 June 2007.
NIST Standard Reference Database.
Finar, I.L. (1974); Organic Chemistry Vol.2 - Stereochemistry and the chemistry of natural products 5th. Ed. Longman
Except where noted otherwise, data relate to standard ambient temperature and pressure.