O-H stretching region

Figure 10. Vibrational spectra of the [HO—Fe—CHs] insertion intermediate in the O—H stretching region. Spectra are obtained by monitoring loss of argon from IR resonance enhanced photodissociation of the argon-tagged complexes [HO—Fe—CH3] (Ar) (n — 1,2).

The spectrum of chemisorbed propylene in the CH and O—H stretching region is shown in Fig. 15. The band at 3593 cm-1 is clearly due to an OH frequency hence, dissociation accompanies propylene adsorption. Careful scrutiny of the region from 1500 to 2000 cm-1 reveals no band assignable to a ZnH band. Since the presence of adsorbed propylene has been found to block out the infrared active hydrogen chemisorption on the ZnO pair sites, we may assume that propylene adsorption occurs as follows ... 

Figure 4.9 FDIR spectrum of phenol (A) and the phenol-BTMA complex (B) in the O-H stretching region. The bottom lines correspond to the theoretical calculations performed for the complex depicted in Figure 4.11 and the phenol monomer, marked with an asterisk. (Reproduced with permission from ref. 20.)...

The effects of hydrogen bonding on the stretching frequencies of hydroxyl and carbonyl groups are summarized in Table 2.2. Figure 2.14 (spectrum of cyclo-hexylcarbinol in the O—H stretch region) clearly illustrates this effect. 

Figure 22 shows some data on methanol pumped in the O-H stretching region by a 35 cm 1 wide pulse at 3400 cm-1. When the pump and probe pulses are time coincident, a coherent artifact is observed at an anti-Stokes shift of 3400 cm1. By about 2 ps this artifact has vanished... 

Fig. 7. Evolution of the differential optical density in the O-H stretching region for MCM-41 irradiated with increasing doses 5 kGy (black), 10 kGy (red), 15 kGy (blue), 20 kGy (green), and 25 kGy (purple).

H. Watanabe and I. Iwata, Theoretical studies of geometric structures of phenol-water clusters and their infrared absorption spectra in the O-H stretching region, J. Chem. Phys. 105, 420-431 (1996). 

Fig. 10.35 INS spectra of bone and model compounds in the O—H stretching region, recorded by two groups of workers. Left spectra recorded on LRMECS (IPNS) [84] (a) nanometre sized crystalline hydroxyapatite (b) micron sized crystalline hydroxyapatite, (c) bovine bone mineral, (d) bone mineral from rat. Right spectra recorded on HET (ISIS) [85] (e) highly crystalline hydroxyapatite, (f) ox femur bone mineral, and (g) brushite CaHP04.2H20. The dashed vertical lines show the position of the hydroxyapatite peaks.

The occurrence of multiple absorption bands at the O-H stretching region in the spectra of samples examined in the neat or solid form is indicative of an involvement of the OH group in more than one type of hydrogen bonding. 

Particularly intriguing is the O-H stretching region from 4000 to 2000 cm which is shown in greater detail in Figure 3.10. 

FIGURE 2.32 The O—H stretch region, (a) Hydrogen-bonded O—H only (neat liquid), (b) Free and hydrogen-bonded O—H (dilute solution), (c) Free and hydrogen-bonded O—H (very dilute solution). 

The emission bands near 620 nm are due to the presence of water. We also observed these bands, characteristic for the high-frequency O-H stretching region at 2900-3700 cm 1 in Raman spectra obtained using the same excitation... 

In the Raman and i.r. spectra of crystalline methyl 3,6-dideoxy-/3-D-ri o-hexo-pyranoside measured at low temperatures, four O-H bands were observed in the O-H stretching region. These were correlated with four distinct hydrogen bonds determined from X-ray data, and deuterium-isotope dilution methods were used to assist the analysis. An interesting study of the far-i.r. spectrum of a pyroelectric sucrose single crystal has been carried out, and the temperature dependence was correlated with polarization of the low-frequency mode (49.5 cm" ) along the binary axis. ... 

Owing to moisture in the atmosphere, pellet spectra often show weak hydroxyl bands when there is no hydroxyl group present in the sample. Care should be used when one interprets spectra of pellets in the O—H stretching region. A check on this problem is to record the spectrum of a disk of the alkali halide alone. 

Cellulose and Xylan. Detailed assignments have been made of bands in the O—H stretching region of the polarized spectra of the polysaccharides, cellulose 1 and... 

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