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The theory and instrumentation for Fourier transform infrared spectrometry are discussed. These instruments measure infrared spectra of the same quality as spectra measured on grating spectrometers in about one thousandth of the time. Their sensitivity advantage for spectra measured in equal times is between a factor of 10 and 100. Commercial spectrometers are now available from nine vendors in North America. Important areas of chemistry include atmospheric monitoring, surface chemistry, and on-line identification of chromatographically separated materials. Many new biochemical and biomedical applications are also becoming apparent, including investigations of phase transitions in lipids and studies of the biocompatibility of implant polymers.

The sections in this article are The Study of Viscoelastic Properties of Polymers by Infrared Spectrometry Dynamic Infrared Linear Dichroism Measured with a Monochromator DIRLD Spectroscopy with a Step‐Scan F ourier Transform Spectrometer Magnitude and Phase Spectra and Two‐Dimensional Correlation Maps Magnitude and Phase Spectra Two‐Dimensional (2‐ D ) Correlation Maps Some Recent Reports of DIRLD DIRLD Spectroscopy with a FT ‐ IR Spectrometer and Digital Signal Processing Summary Appendix: The Photoelastic Modulator

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We report here the first observation of surface-enhanced infrared spectroscopy on platinized platinum surfaces, as well as a thorough explanation of the resulting spectra. Smooth platinum electrodes were electrochemically platinized to produce regular metal island surfaces that led to enhanced absorption of the infrared spectrum of adsorbed carbon monoxide. The infrared spectrum of CO adsorbed from an aqueous electrolyte onto the electrode surface was measured in situ by external reflection spectrometry. The amount of adsorbed CO was estimated from the difference spectrum before and after the CO was oxidized to CO 2 by finding the ratio of the absorbance of adsorbed CO prior to oxidation to the absorbance of dissolved carbon dioxide formed when the adsorbed CO was oxidized. By varying the platinization conditions, platinized Pt surfaces that yielded IR band enhancements of up to 20 times that of CO adsorbed on smooth Pt electrodes were prepared. When CO was adsorbed on a smooth Pt electrode, the shape of the band due to the CO stretching mode was quite symmetrical. As the degree of platinization was increased, the band became asymmetrical, then bipolar, and finally appeared as a reflection maximum. This behavior was simulated using the Bergman representation of effective dielectric function.

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