An Assessment of the Assignment of Characteristic N-O Vibrations in Aromatic N-Oxides

Abstract

The use of “characteristic” N-O group frequencies, in characterising metal complexes with aromatic N-oxides is widespread. The most popular assignments of the N-O in-plane and out-of-plane bends of N-oxides are shown to be in error, while the validity of transferring the N-O assignments of pyridine N-oxide to larger aromatic N-oxide systems is cautioned.

Key Words:

• aromatic N-oxides
• infrared
• vibrational assignments