Infrared assignments

Bohm et al. (1995) have studied the protective effect of 3-CAR and LYC against cell membrane damage by N02 showing that LYC is more than twice as effective as 3-CAR. These authors observe two species from the reaction, both in the infrared, assigning them to the radical cation and a radical addition product. 

The infrared spectrum of pseudoephedrine hydrochloride is shown in Figure 1. It was obtained as a 0.2% dispersion of pseudoephedrine hydrochloride in KBr with a Nicolet Model 7199 FT-IR spectrophotometer.2 Table I gives the infrared assignments consistent with the structure of pseudoephedrine hydrochloride. 

Table I. Infrared Assignments and Apparent Integrated Absorption Intensity...

L. G. Tensmeyer and C. D. Underbrink for the infrared assignments and C. L. Winely for the microbiological assay portions. 

Table 7.1 shows the infrared assignments for some of the common metal carbonates. Significant amounts of impurities can cause the infrared peaks to shift noticeably, so X-ray diffraction is still the most reliable analytical tool for crystal form assignment. Additional information on infrared absorption of carbonates [15], relative thermodynamic stabilities and transformation between phases has been published [16, 17]. 

Metal Carbonate form Infrared assignments, wave numbers, cm ... 

Figure 7. Infrared assignments illustrated with the spectrum of zeolite Y, Si/Al of 2.5...

The Raman frequencies of the protein backbone vibrations are often different than the infrared frequencies and thus infrared assignments are needed for structure determinations from infrared spectra. Such structural information is needed from the... 

Infrared Assignments for Clldinium Bromide Frequency (cm ) Characteristic of... 

The observed bands were classified by Flanigen et al. [112] into two types, namely internal modes of the TO4 tetrahedra ( intra-tetrahedral modes, cf. Sect 5.2) and external modes ( inter-tetrahedral modes) of the zeolite fi-amework. Table 1 summarizes the zeolite infrared assignment according to the FKS correlation. The internal vibrations represent structure-insensitive modes, and no distinction has been made between the modes of Si04 and AIO4 tetrahedra. The bands of external modes were observed to be sensitive to the structure, and their positions in the spectra are shifted in dependence on the framework topology and on the nsi/n i ratio. Even though this classification proved to be very successful in many applications, from a theoretical point of view such a division into... 

Table 1. Zeolite infrared assignments foUowing the FKS correlation [112]...

Figure 1. Infrared assignments illustrated with the Y spectrum. Full lines internal TO4 structure insensitive. Dashed lines external TO4 linkages structure sensitive.

Figure 6.2 illustrates the infrared spectrum of poly(methyl methacrylate) (PMMA). The structure of PMMA is -[-CH2-C(CH3)(COOCH3)-] -. The infrared spectrum of PMMA results from the group frequencies of the C-C and C-H groups of the backbone chain, the C-C, C=0 and C-0 units of the ester group and the C-H units of the methyl substituent. The infrared assignments for this spectrum are listed in Table 6.1. 

The infrared analysis of plant material has traditionally relied upon the use of harsh chemicals and modification of the intractable cell walls. Plants comprise up to 80% of their dry weight of carbohydrates, with the most important including cellulose, starches, pectins and sugars, such as glucose and sucrose. The mid-infrared assignments of conunon plant carbohydrates are listed in Table 7.9 [50, 51]. The advent of FTIR microspectroscopy has allowed for the investigation of localized regions of plant cells which require no modification [50, 52],... 

Table 3. Fourier Transform Infrared Assignments for Tetramethyl Bis A (Neat)...

Proposed principal functional groups on carbon surfaces and their corresponding infrared assignments... 

Infrared Assignments (in cm ) for Thorium Hyponitrite-Nitrate Hydrates. 

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