Applications of infrared spectroscopy

Infrared spectroscopy is commonly used to identify and to determine quantitatively the amount of various substances present in mixtures. For the explanation of fundamental ideas we restricted our attention to the infrared spectra of very simple compounds. Even then, we observed that the spectrum can become very complicated. When a multitude of atoms is present, as in most organic compounds, the spectrum takes on a different appearance much broader bands are in evidence. 

Quantitative FT-IR methods have been used to analyze binary mixtures of quin-acridone and perylene pigments. 

Using quantitative FT-IR, C.I. PV19 was measured down to 5% concentration in C.I. PR122. The C.I. PV19 bands at 960 cm , 849 cm , 748 cm , or 480 cm may be used. In this case, the reference band of C.I. PR122 at 1205 cm is used for obtaining absorbance ratios. Other notable applications of quantitative FT-IR are the determination of phthahmido derivatives (PM) of copper phthalocyanines. Samples are prepared in a similar manner as described above for the quin-acridones. In this case, the carbonyl band between 1710 and 1720 cm was used for calculating the amount of the PM derivative. 

Red scan PR254 premix zero time. Black scan PR254 after mixing for 10 min. Pink scan commercial PR254 dispersion. 

Similar work has been done with binary mixtures of other quinacridones. C.I. PV19 was measured at the 3.5% level in C.I. PR202 based on the absorbance of the C.I. PV19 band at 752 cm and the PR202 band at 840 cm. C.I. PR122 was 

The amount of C.I. PV29 in C.I. PR179 can be measured to below 1% using the absorbance of the C.I. PV29 band at 460 cm and the reference absorption band of C.I. PR 179 at 515 cm . This method is used routinely to monitor the amount of C.I. PV29 in C.I. PR179 at levels below 2.5%. 

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The second block of experiments provide examples of the application of infrared spectroscopy. 

A. L. Smith, in J. R. Durig, ed.. Chemical, Biological and Industrial Applications of Infrared Spectroscopy,]ohn Wiley Sons, Inc., New York, 1985. 

Tosi, C. and Ciampelli, F. Applications of Infrared Spectroscopy to Ethylene-Propylene Copolymers. Vol. 12, pp. 87-130. 

The most common application of infrared spectroscopy in catalysis is to identify adsorbed species and to study the way in which these species are chemisorbed on the surface of the catalyst. Sometimes infrared spectra of adsorbed probe molecules such as CO and NO give valuable information on adsorption sites on a catalyst. We will first summarize the theory behind infrared absorption. 

Cesaro, S. N. Torracca, E. (1988). Early applications of infrared spectroscopy to chemistry. Ambix, 35, 39-46. 

Some applications of infrared spectra. A few of the applications of infrared spectroscopy may be mentioned. 

Many excellent reviews on the application of infrared spectroscopy for characterization of silicoaluminates have been written and some are referenced here if a more thorough coverage of this topic is desired [81-89]. The purpose of this section is not to cover infrared spectroscopy of zeolites in great detail, but to give the reader an overview of the utility of the technique and the types of information that can be obtained. References are provided if more in-depth information is desired. 

Infrared and Raman spectroscopy are nondestructive, quick and convenient techniques for monitoring the course of solid-phase reactions, and have therefore been widely used for the characterization of polymer supports and supported species [156-160]. In fact, the application of infrared spectroscopy in solid-phase synthesis has received much attention and has been the subject of several recent reviews [127, 128, 161-164]. Reactions involving either the appearance or disappearance of an IR-active functional group can be easily monitored using any of the IR techniques described in this section. Some beads are typically removed from the reaction mixture, then they are quickly washed and dried prior to IR analysis. Traditionally, polymer supports are diluted and ground with KBr, then conventional FT-IR analysis of the KBr disk is carried out Although this is a commonly used... 

Raman, A. Kuban, B. Razvan, A. (1991) The application of infrared spectroscopy to the study of atmospheric rust systems. I. Standard spectra and illustrative applications to identify rust phases in natural atmospheric corrosion products. Corrosion Sci. 32 1295-1306... 

R. N. Jones, in Chemical, Biological, and Industrial Applications of Infrared Spectroscopy (J.R. Durig, Ed.), John Wiley and Sons, Chichester, UK (1985). 

F. S. Parker, Applications of Infrared Spectroscopy in Biochemistry, Biology, and Medicine, Plenum, 1971. 

Infrared and Raman spectroscopy are in current use fo r elucidating the molecular structures of nucleic acids. The application of infrared spectroscopy to studies of the structure of nucleic acids has been reviewed,135 as well as of Raman spectroscopy.136 It was noted that the assignments are generally based on isotopic substitution, or on comparison of the spectrum of simple molecules that are considered to form a part of the polynucleotide chain to that of the nucleic acid. The vibrational spectra are generally believed to be a good complementary technique in the study of chemical reactions, as in the study76 of carbohydrate complexation with boric acid. In this study, the i.r. data demonstrated that only ribose forms a solid complex with undissociated H3B03, and that the complexes are polymeric. 

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