<i>N</i>-Methyl compounds exhibit a weak to medium absorption band in the 2820–2760 cm<sup>−1</sup> region, which is characteristic for the <i>N</i>-methyl group. This diagnostic test is shown to be applicable to potassium bromide spectra and to the wide variety of molecules having an <i>N</i>-methyl substituent examined. Aldehydes, amino acid hydrochlorides, secondary and tertiary alkylamines, methoxy compounds, and nitrogen heterocyclic molecules exhibit absorption which may overlap this region and the detection of an <i>N</i>-methyl substituent for these classes of compound may be less definite. This diagnostic band is absent in potassium bromide spectra of the amine salts in which the nitrogen lone pair of electrons is involved in bond formation.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
Login to access OSA Member Subscription