Brian C. Smith


Spectral Subtraction

May 01, 2021

Determining the components in a mixture can be a significant challenge in infrared spectroscopy, but spectral subtraction can help. We show the proper way to perform spectral subtraction, and the pitfalls to avoid.

The Grand Review I: Why Do Different Functional Groups Have Different Peak Positions?

November 01, 2020

Articles in this column have addressed five main areas: theory, functional groups containing the C-H bond, those containing the C-O bond, those with the C=O bond, and those with organic nitrogen compounds. Here, we review the concepts.

Organic Nitrogen Compounds VIII: Imides

March 01, 2020

Here, we continue our examination of the infrared (IR) spectra of organic nitrogen compounds with imides, which are a common chemical intermediate. IR can be used not only to identify imides, but also to distinguish between straight chain and cyclic imides. We explain how.

Organic Nitrogen Compounds V: Amine Salts

September 01, 2019

The amine salt functional group contains ionic bonding, and is extremely polar, giving rise to a number of intense and uniquely placed peaks that are easy to identify for primary, secondary, and ter tiary amines.