Alcohol infrared spectra

Benzyl alcohol Infrared spectrum has peaks for O—H and sp C—H lacks peak for C=0... 

Section 16 18 An H—C—O—C structural unit m an ether resembles an H—C—O—H unit of an alcohol with respect to the C—O stretching frequency m its infrared spectrum and the H—C chemical shift m its H NMR spectrum Because sulfur is less electronegative than oxygen the H and chemical shifts of H—C—S—C units appear at higher field than those of H—C—O—C... 

Fingerprint region (Section 13 20) The region 1400-625 cm of an infrared spectrum This region is less character istic of functional groups than others but varies so much from one molecule to another that it can be used to deter mine whether two substances are identical or not Fischer esterification (Sections 15 8 and 19 14) Acid cat alyzed ester formation between an alcohol and a carboxylic acid... 

The infrared spectra of alcohols change markedly with increasing concentration. For example, at very low concentration, the infrared spectrum of te/t-butyl alcohol in carbon tetrachloride contains a single sharp band at approximately 3600 cm corresponding to the OH stretching motion. As the alcohol s concentration increases (by adding more alcohol to the sample), a second broad OH stretch band grows in at approximately 3400 cm and eventually replaces the other band. 

B) Acylation of 6-Aminopenicillanic Acid To a solution of the aryl halocarbonyl ketene (0.1 mol) in methylene chloride (sufficient to provide a clear solution and generally from about 5 to 10 ml per gram of ketene) there is added the proper alcohol RjOH (0.1 mol), in this case 5-indanyl alcohol. The reaction mixture is maintained under an atmosphere of nitrogen and stirred for a period of from 20 minutes to 3 hours, care being taken to exclude moisture. The temperature may range from about -70° to about -20°C. The infrared spectrum of the mixture is then taken to determine and confirm the presence of the ketene ester. A solution of 6-aminopenicillanic acid-triethylamine salt (0.1 mol) in methylene chloride (50 ml) is added and the mixture stirred at -70° to -20°C for 10 minutes. The cooling bath is then removed and the reaction mixture stirred continuously and allowed to warm to room temperature. 

Aero Hydrolysis. A solution of kasugamycin hydrochloride (1.5 grams, 3.46 mmoles) dissolved in 15 ml. of 6N hydrochloric acid was heated at 105°C. for five hours in a sealed tube. The solution was condensed to 5 ml. under a reduced pressure and the addition of 50 ml. of ethyl alcohol afforded a crude solid overnight. It was recrystallized from aqueous ethyl alcohol, showing m.p. 246°-247°C. (dec.). It showed no depression in the mixed-melting point and completely identical infrared spectrum with d-inositol which was supplied by L. Anderson of the University of Wisconsin. The yield was 81% (503 mg., 2.79 mmoles). Anal Calcd. for CgH12Og C, 40.00 H, 6.71 O, 53.29 mol. wt., 180.16. Found C, 40.11 H, 6.67 O, 53.33 mol. wt., 180 (vapor pressure osmometer). 

Figure 4 illustrates the infrared spectrum for a sample of PPE. The absorptions of the peaks at 3.4, 6.9 and 7.3 pm were assigned to C-H stretch and C-H bending frequencies in CH2 and CH3 (33). These absorptions are proportional to the surface density of deposited ethane (16). However, the absorptions at photons near 10 pm are attributable to OH deformations and CO stretchings of alcoholic groups and vibrations of alkyl ketones (22). They also indicate the existence of branches in unsaturated chain (33). 

Tris(dimethyl sulfoxide)indium(III) chloride is a white crystalline nonhygro-scopic compound, soluble in alcohols, ethyl acetate, and nitromethane. Decomposition occurs at 130°. The infrared spectrum and the results of thermal stability studies have been reported.6 The presence of dmso can be verified from the infrared spectrum,6 which shows C—H vibrations, and =0 at 945, 960, and 995 cm. ... 

The compound [N(PPh3)2][Ru3H(CO)10(SiEt3)2] is a red, crystalline material. The crystals are only slightly air sensitive and decompose above 120 °C over a broad temperature range. They dissolve in polar solvents such as THF, dichloromethane, trichloromethane, acetonitrile, methyl alcohol, or acetone. The red solutions are much more sensitive to oxygen than the solid. The infrared spectrum of a THF solution displays characteristic absorptions at 2070(w), 2019(m), 1992(m), 1984(vs), 1975(w), 1965(m), and 1925(sh) cm-1 (Nicolet MX-1 Spectrometer). The structure of the compound, tautomerism of the CO groups, and electrochemical characteristics have been reported.9... 

We therefore studied the effect of temperature and of concentration on the position of the hydroxyl peak in simple alcohols (methanol, ethanol, etc.) in the pure state, and in carbon tetrachloride or chloroform solutions. Some of the results of this work have already been reported [1]. A plot of peak position against concentration gives curves such as that in Fig. la. Interpretation of this type of curve from the N.M.R. data alone is impossible. It is clear that several different species (monomer, dimer, polymers) are contributing their effect, but because of the averaging phenomenon only a single OH peak, representing the weighted mean of all these species, is observed. We have now used infrared spectral data to clarify the situation. A careful examination of the infrared spectrum of all normal aliphatic alcohols... 

Propargyl alcohol HC = 0—CHgOH ako gives an infrared spectrum indicative of only a monomer dimer equilibrium, although since here there can be no steric hindrance there is no obvious reason why this should be the case. Its nuclear resonance shift with dilution is more akin to the kind shown by polymer-forming alcohols, and the anomaly... 

Perhaps you are curious as to why absorptions are observed in the infrared spectrum of alcohols that correspond both to free and bydrogen-borided hydroxyl groups, whereas only one OH resonance is observed in their proton nmr spectra. The explanation is that the lifetime of any molecule in either the free or the associated state is long enough to be detected by infrared absorption but much too short to be detected by nmr. Consequendy, in the nmr one sees only the average OH resonance of the nonhydrogen-bonded and hydrogen-bonded species present. The situation here is very much like that observed for conformational equilibration (Section 9-IOC). 

Fig. 11. Infrared spectrum of oriented polyvinyl alcohol. — E perpendicular to stretching direction - — E parallel to stretching direction [Krimm, Liang, and Sutherland (704)]...

If the unknown, neutral, oxygen-containing compound does not give the class reactions for aldehydes, ketones, esters and anhydrides, it is probably either an alcohol or an ether. Alcohols are readily identified by the intense characteristic hydroxyl adsorption which occurs as a broad band in the infrared spectrum at 3600-3300 cm-1 (O—H str.). In the nuclear magnetic resonance spectrum, the adsorption by the proton in the hydroxyl group gives rise to a broad peak the chemical shift of which is rather variable the peak disappears on deuteration. 

The broad, intense absorption at 3300 cm-1 is attributable to a hydroxyl group. Although both phenol and benzyl alcohol are possibilities, the peaks at 2800-2900 cm-1 reveal the presence of hydrogen bonded to -hybridized carbon. All carbons are sp2-hybridized in phenol. The infrared spectrum is that of benzyl alcohol. 

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