Infrared spectra methanol

After washing the combined extracts with ammonium chloride solution and water and working up in the usual way a white solid (IV) is obtained which after one recrystalli2ation from aqueous methanol has MP 242° to 243°C. The infrared spectrum of this compound indi-... 

In 1977 Ford and co-workers showed that Ru3(CO)12 in the presence of a ca. fiftyfold excess of KOH catalyzes the shift reaction at 100°C/1 bar CO (79). The effectiveness of the system increased markedly as temperature was increased (rate of hydrogen formation approximately quadrupled on raising the temperature from 100° to 110°C), and over a 30-day period catalyst turnovers of 150 and 3 were found for Ru3(CO)12 and KOH, respectively. Neither methane nor methanol was detected in the reaction products. Although the nature of the active ruthenium species could not be unambiguously established, infrared data indicated that it is not Ru3(CO)12, and the complexity of the infrared spectrum in the... 

K. N. Woods and H. Wiedemann, The influence of chain dynamics on the far infrared spectrum of liquid methanol. J. Chem. Phys. 123, 134506 (2005). 

In these results, COad does not seem to exist at 600 mV or higher potentials, llie electrochemical studies, however, showed that the coverage increases when the potential is kept at 600 mV. To solve this discrepancy, a higher concentration of methanol was used. Figure 3-31 shows the change of infrared spectrum with time while the potential was held at 600 mV in 0.5 M sulfuric add with 1 M methanol. The reference state was at 1050 mV, the last step of deaning, at which potential, the electrode was pushed onto the window. 

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... 

Attempts were made to reduce any aldehyde and ketone function with sodium borohydride. A 1.5-gram sample was weighed into a 100-ml. reaction flask and suspended in 10 ml. of methanol. A solution of 0.3 gram of sodium borohydride in 25 ml. of 0.1 IV sodium hydroxide was added to the sample over a period of 15 minutes. The mixture was refluxed under nitrogen for 6 hours, filtered, and washed thoroughly with water. The amount of aldehyde and ketone was estimated by the decrease in the 5.8 micron peak in the infrared spectrum of the treated sample as compared with the untreated sample. 

Trimethoxysilyl)propyloctadecyldimethylammonium chloride (SiQAC) was obtained from Dow Coming Corporation, Midland, MI, as a 40% solution in methanol. A suitable aliquot of this solution was rotary-evaporated to remove most of the methanol and then diluted to 10 ml with an appropriate solvent. An infrared spectrum was recorded immediately after this procedure to obtain the initial methanol concentration. It was observed that complete evaporation of the methanol to solid SiQAC results in hydrolysis of the methoxy groups and condensation of the silanol groups to form siloxane bonds. Scheme 1 shows the structures and abbreviations of all the compounds used in this investigation. 

The methoxylation can be carried out by reacting silica with methanol vapor at 300-400°C, or by refluxing silica in methanol (21,36). Because the infrared spectrum of the modified surface is well understood (36) we chose to use this system as a model to test the feasibility of using Raman spectroscopy (21 ) for studying such surface modification procedures. 

After the reactor had been cleaned, evacuated and purged with N2, 1.29 g of 2,5-di-tert-butyl-l,4-benzoquinone (5.85 mmol) were added, taking care that the benzoquinone did not touch the ATR sensor. After the desired jacket temperature had been reached, a reference background infrared spectrum was recorded. Then, 19.2 mL dioxan, 8 mL EtOH and 8 mL tert-butyl hydroperoxide (70% solution in water, 58.5 mmol) were added, the stirrer was turned on to 400 rpm and the desired reaction temperature was set. After degassing the solution for 3 minutes with N2, Triton B (0.8 mL of a 40% solution in methanol, 1.78 mmol) was added within 24 seconds into the closed reactor to start the reaction. 

The (1,1-diphenyl) phosphonitrile fluoride trimer is a colorless crystalline solid that melts at 68.5-69.5°C. It can be recrystallized from n-pentane, n-heptane, petroleum ether, or absolute methanol. It is also soluble in diethyl ether, carbon disulfide, and chloroform, but it is insoluble in and not attacked by water. The infrared spectrum shows a strong phosphorus-nitrogen stretching mode at 1250-1265 cm."1. Strong bands at 914-920, 900-906 cm."1 and at 812-820 cm."1 are associated, respectively, with phosphorus-fluorine asymmetric and symmetric stretching modes. 

Considerably better results are obtained with copolymers of vinyl chloride and lead undecylenate. The lead salt of undecylenic acid, (CH2=CH—(CH2)g—COO)2Pb, can be copolymerized by free radicals in bulk or in methanol solution. The composition of the resulting polymer has been determined by infrared spectroscopy (4). Figure 5 shows an infrared spectrum of a film of homopolymeric PVC and of a copolymer obtained from vinyl chloride and lead undecylenate. At wavenumbers... 

The infrared spectrum of methanol shows O — H, C — H, and C — O stretching absorptions, together with absorptions from several bending modes. 

A nonlinear molecule with n atoms generally has 3n — 6 fundamental vibrational modes. Water (3 atoms) has 3(3) -6 = 3 fundamental modes, as shown in the preceding figure. Methanol has 3(6) - 6 = 12 fundamental modes, and ethanol has 3(9) - 6 = 21 fundamental modes. We also observe combinations and multiples (overtones) of these simple fundamental vibrational modes. As you can see, the number of absorptions in an infrared spectrum can be quite large, even for simple molecules. 

Pentacarbonyl(methoxymethylcarbene)chroniiuin(0) is a dull-yellow, crystalline solid mp 34°. It slowly decomposes in the solid state at room temperature in air, but may be stored at 5° for a few days before appreciable decomposition is observed. It is soluble in aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and other common laboratory solvents such as benzene, 1,4-dioxane, tetrahydrofuran, chloroform, dichloromethane, and methanol, and is slightly soluble in ethanol. The infrared spectrum (cyclohexane solution) has v(CO) bands at 2065, 1985, 1965, and 1950 cm-1. The H nmr spectrum in chloroform-d shows the methoxy proton resonance at t6.15 and the methyl proton resonance at t7.70. Other physical properties are reported in the literature.6,7... 

Identification The volatile oil distilled from an oleoresin is similar in its physical and chemical properties, including its infrared spectrum, to that distilled from the spice of the same origin. To obtain the volatile oil from the oleoresin, proceed as directed under Volatile Oil Content, Appendix VHI. Residual Solvent Chlorinated Hydrocarbons (total) Not more than 0.003% Acetone Not more than 0.003% Isopropanol Not more than 0.003% Methanol Not more than 0.005% Hexane Not more than 0.0025%. 

The blue-green adduct was heated in vacuum at 45° for 20 hours to yield emerald-green crystals of [Rh(OCOCH3)2]2. A check on the removal of methanol can be made periodically by taking an infrared spectrum. Overall yield is 3.2 g. (76% based on RhCl3-3H20). Anal. Calcd. C, 21.74 H, 2.74. Found C, 21.79 H, 2.99. 

The infrared spectrum (Nujol mull) of Na2[ReH9] has URell) at 1835(s), (br) and 5(ReH) at 745(s), ca. 720(sh), and 630(sh) cm.-1. In aqueous alkali rRe-H = 19.1. The compound is soluble in water and methanol, slightly soluble in ethanol, and insoluble in 2-propanol, acetonitrile, ether, and tetrahydrofuran. Alkali stabilizes the water and methanol solutions. With acids... 

Fig. 6-9. The vc o stretching absorption band in the infrared spectrum of camphor (a) in the gas phase, (b) in n-heptane, (c) in tetrachloromethane, (d) in pyridine, (e) in methanol, and (f) in l,l,l,3,3,3-hexafluoro-2-propanol [378].

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