Hydrogen-bonded OH groups

Shindo studied the hydrogen-bonding ability of a fairly long series of substituted pyridine 1-oxides with methanol in chloroform solution and found that the OH frequency of the hydrogen-bonded OH group in methanol is well correlated with the <7-values. For four compounds, the intensity of the same band is also well correlated. In a similar study the OH frequencies of phenol vary monotonically with the CT-values, but not in a linear fashion. 

These cements set in 3-5 to 56 minutes (at 37 °C). Infrared spectroscopy showed that as the cement set there was loss of acid carbonyl groups and OH groups associated with calcium hydroxide, and simultaneously formation of ionic carboxylate groups and hydrogen-bonded OH groups. 

Large bandwidth, red-shifted infrared band corresponding to hydrogen bonded OH groups at 3400 cm. ... 

The difference in frequency between the parallel type bonds in cellulose II and III and those of cellulose I is appreciable and suggests that the molecular form of the cellobiose residue is different in cellulose I from the other two modifications. However, since the frequency of a hydrogen-bonded OH group is very sensitive to the 0 0 distance, this difference in molecular configuration may not be very great. 

Little comment can be made about the hydrogen-bonded OH groups that absorb close to 3300 cm."1. It is unlikely, however, within the rank range of resinites covered here that much variation in the intensity of this absorption would be recorded. The broad region of absorption between 1100 and 1300 cm."1 common to vitrinite and sporinite spectra is also found in the resinite spectra. The peak at 1270 cm. 1 almost certainly corresponds to the 1250 cm."1 band assigned by other workers to hydrogen-bonded phenolic structures. Fol-... 

V is equal to the sum of the surrounding metal atoms sj. For complexes in the solution, Brown theory predicts that oxygen ligand interacts by three hydrogen bonds, OH group by the one acceptor and one donor hydrogen bonds, whereas OH2 group by two donor bonds. 

The products discussed in this report are 22-68% aluminum depleted, relative to the respective starting materials, yet the hydroxyl region of the infrared spectrum shows that few hydrogen bonded OH groups were created as a result of the treatments (see the "z" values in the Tables). The value "z" is calculated from the measured absorbance at 3710 cm"1 in the hydroxyl region of the Infrared spectrum, compared to that measured for a standard sample with a known number of defect sites (1). "z" numerically... 

Fig. 2 (a) Two inde[>endent single-well potential curves for the vibrating OH groups, (b) The double-well potential curve for the hydrogen-bonded OH group (-OH 0= vs. =0- HO-). The solid curve indicates a symmetric combination of the two individual proton wave-functions and the broken curve is for an antisymmetric combination. The tunnelling splitting (Ao) is also shown. 

The Koppel-Paju B scale was proposed to measure solvent hydrogen bond basicity, based on solvent shifts of the IR stretching frequencies of the free and hydrogen bonded OH group of phenol in CCI4 [Koppel and Paju, 1974]. 

Use SpartanView to measure the 0-H bond distance and identify the 0-H stretching vibration of (ert-hutyl alcohol. Next, measure the O—H bond distances and identify the two stretching vibrations in tert-butyl alcohol dimer. How does dimerization affect the hydrogen-bonded -OH group, and how does it affect the other -OH group ... 

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