Ethanol NMR spectra

Reaction progress and individuality of compounds controlled over Silufol UV-254 plates. Infrared spectrum was taken on the Specord lR-75 device, UV spectrum - on the spectrometer Specord UV VIS in ethanole, NMR spectrum -on the spectrometer WP-200 SY (200 MHz), internal standard - TMS. 

Figure 18.16 One-dlmenslonal NMR spectra, (a) H-NMR spectrum of ethanol. The NMR signals (chemical shifts) for all the hydrogen atoms In this small molecule are clearly separated from each other. In this spectrum the signal from the CH3 protons Is split Into three peaks and that from the CH2 protons Into four peaks close to each other, due to the experimental conditions, (b) H-NMR spectrum of a small protein, the C-terminal domain of a cellulase, comprising 36 amino acid residues. The NMR signals from many individual hydrogen atoms overlap and peaks are obtained that comprise signals from many hydrogen atoms. (Courtesy of Per Kraulis, Uppsala, from data published in Kraulis et al.. Biochemistry 28 7241-7257, 1989.)...

Compound A undergoes hydrolysis of its acetal function in dilute sulfuric acid to yield 1,2-ethanediol and compound B (CgHg02), mp 54°C. Compound B exhibits a carbonyl stretching band in the infrared at 1690 cm and has two singlets in its H NMR spectrum, at 8 2.9 and 6.7, in the ratio 2 1. On standing in water or ethanol, compound B is converted cleanly to an isomeric substance, compound C, mp 172—173°C. Compound C has no peaks attributable to carbonyl groups in its infrared spectrum. Identify compounds B and C. 

Solid sodium nitrite (0.97 g) was added at room temperature with stirring over a period of one hour to a solution of 2-chloro-9-(2-hydroxyethoxymethyl)adenine (0.5 g) in glacial acetic acid (10 ml). The reaction mixture was stirred for an additional A A hours. The white solid was removed by filtration, washed with cold acetic acid and then well triturated with cold water to remove the sodium acetate present. The solid product was retained. The combined acetic acid filtrate and wash was evaporated at reduced pressure and 40°C bath temperature and the residual oil triturated with cold water. The resulting solid material was combined with the previously isolated solid and the combined solids dried and recrystallized from ethanol to give 2chloro-9-(2-hydroxyethoxymethyl)+iypoxanthine (0.25 g), MP>310°C. Elemental analysis and NMR spectrum were consistent with this structure. 

FIGURE I The NMR spectrum of ethanol. The red letters denote the protons that give rise to the associated peaks. 

Stephadiamine (16) was isolated as a minor component from the ethanolic extract of the whole plant of Stephania japonica collected in Taiwan (6). The IR spectrum of stephadiamine (16) exhibited bands at 3375 (NH2) and 1720 cm 1 (5-lactone), and the H-NMR spectrum (Table II) showed the presence of one JV-methyl and two methoxyl groups. Its mass spectrum revealed a base ion peak at m/z 243 of stephamiersine-type cleavage (Table V) (6). 

If you take a pure sample of ethanol, and run its NMR spectrum in dry CDCI3, the hydroxyl proton will appear as a well-defined triplet, which couples to the adjacent -CH2-, rendering it a multiplet. This is because the hydroxyl proton remains on the oxygen for relatively long periods of time, as there is nothing in the solution to entice it off, i.e., exchange (if any) is said to be very slow on the NMR timescale (less than about 1 s). 

Scheme 3 shows the details of the synthetic strategy adopted for the preparation of heteroleptic cis- and trans-complexes. Reaction of dichloro(p-cymene)ruthenium(II) dimer in ethanol solution at reflux temperature with 4,4,-dicarboxy-2.2 -bipyridine (L) resulted the pure mononuclear complex [Ru(cymene)ClL]Cl. In this step, the coordination of substituted bipyridine ligand to the ruthenium center takes place with cleavage of the doubly chloride-bridged structure of the dimeric starting material. The presence of three pyridine proton environments in the NMR spectrum is consistent with the symmetry seen in the solid-state crystal structure (Figure 24). 

UV spectrum A run in ethanol UV spectrum B run in ethanol/NaOH NMR spectrum A sweep offset by 120 Hz NMR spectrum B sweep offset by 210 Hz After deuteration... 

Figure 2.39 NMR spectrum of ethanol (CH3 CH2 OH). The three peaks are due to the three groups in the compound, which can be split into multiple peaks using a higher resolution. The peak at zero chemical shift is due to the reference compound, DSS.

A 100 MHz NMR spectrum of a mixture of ethanol (C2H6O) 5 18.3 (CH3), 5 57.8 (CH2) and bromoethane (C2HsBr) 5 19.5 (CH3) and 6 27.9 (CH2) in CDCI3 solution is given below. The spectrum was recorded with a long relaxation delay (300 seconds) between acquisitions and with the NOE suppressed. Estimate the relative proportions (mole %) of the 2 components from the peak intensities in the spectrum. 

The different types (doublet, triplet, and so on) exhibit a characteristic ratio of intensities. Doublets are equally intense. Triplets have a more intense central peak flanked by two equal peaks of lesser intensity. A quartet has two equally intense central peaks with two smaller outer peaks that are equal to each other in intensity. See Figure 5-4 for the NMR spectrum of ethanol. 

Solid Mo02Br2(DMF)2 melts at 139-141°C with decomposition. The IR spectrum, taken as a KBr dispersion, has characteristic bands for i moO 903 and 940 cm The NMR spectrum in acetone-t/g exhibits signals at S 3.03 (s, 3H, CHa), 3.22 (s, 3H, CH3), 8.26 (s, IH, CH). The complex is insoluble in hexane and diethyl ether and is soluble in methanol, ethanol, dichloromethane, chloroform, acetone, dimethyl formamide, and dimethyl sulfoxide. It is stable in air at room temperature and can be manipulated without special care. This product is specially useful for the synthesis of a number of adducts with pyridine and related bases, since the dimethyl formamide displaced can be readily removed by washing with most common organic solvents. 

As an example. Fig. 18 shows CP/MAS NMR spectra recorded during the investigation of surface ethoxy species (7S) formed on acidic zeolite HY ( si/ Ai = 2.7) by a SF protocol. Figure 18a shows the CP/MAS NMR spectrum recorded after a continuous injection of C-1-enriched ethanol, CHI CHzOH, into the MAS NMR rotor reactor containing calcined zeolite HY. The ethanol was injected at room temperature for 10 min. Subsequently, the loaded zeolite was purged with dry nitrogen (200 mL/min) at room temperature for 2h. 

Trimethylsilyl ethanol [2916-68-9] M 118.3, b 53-55 /llmm, 75 /41mm, 95 /100mm, 0.8254, np 1.4220. It the NMR spectrum is not clean then dissolve in Et2O, wash with aqueous NH4CI solution, dry (Na2SO4), evaporate and distil. The 3,4-dinitrobenzoyl deriv has m 66 (from EtOH). [NMR JACS 79 974 7957 Z Naturforsch 14b 137 7959],... 

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