Nuclear magnetic resonance spectroscopy alcohols

The trifluoroethyl (CF3CH2—) derivative of organic acids and alcohols has been found to be useful for distinguishing carboxyl from primary hydroxyl from secondary hydroxyl functional groups by F nuclear magnetic resonance spectroscopy (Roller and Dorn, 1982). This derivative is formed under conditions shown in reaction (4) ... 

Brunow, G., and Lundquist, K. (1980) Comparison of a synthetic dehydrogenation polymer of coniferyl alcohol with milled wood lignin from spruce, using H NMR nuclear magnetic resonance spectroscopy. Pap Puu. Helsinki, Suomen Paperi ja Puutavaralehti Oy 62(11), 669-670. 

Seo S, Tomita Y, Tori K, Yoshimura Y (1978) Determination of the Absolute Configuration of a Secondary Hydroxy Group in a Chiral Secondary Alcohol Using Glycosidation Shifts in Carbon-13 Nuclear Magnetic Resonance Spectroscopy. J Amer Chem Soc 100 3331... 

Nuclear magnetic resonance spectroscopy carbon, 510-517, 535 alcohols, 606... 

The assignment of these isomers was confirmed by nuclear magnetic resonance spectroscopy on a Perkin-Elmer 60 Mc./sec. NMR spectrometer, after removal of -OH by exchange with deuterium oxide. The spectrum of the cw-alcohol showed a single broad peak, while that of the trans-alcohol showed two peaks they thus resembled the spectra of the corresponding hydrocarbons (8). 

The Pd(MeCN)4(BF4)2-catalysed conversion of allylic alcohols into allylic silanes and boronates has been investigated by product studies, kinetic studies, and H, B, F, and Si NMR (nuclear magnetic resonance) spectroscopy. The two reactions that occur by the same mechanism involve the formation of a palladium allylic alcohol [(a -allyl) palladium] complex after the alcohol is activated by BF3 formed from a BF4 ion of the catalyst. Then, a rate-determining, stereoselective transmetalation with Si(Me)2 and a reductive elimination of the palladium gives the linear silane. B2pin2 replaces Si(Me)2 in the borylation reaction. 

Roberts J D, Weigert F J, Kroschwitz J I, Reigh H J 1970 Nuclear magnetic resonance spectroscopy. Carbon-13 chemical shifts in acyclic and alicyclic alcohols. J Am Chem Soc 92 1338-1347... 

Acidify the aqueous phase D, remaining after the removal of alcohols (see above) with concentrated hydrochloric acid and extract the liberated thioacid with diethyl ether. Liquid - liquid extraction for 4 hours produces more material, but shaking with 50 cm of diethyl ether for about 1 min normally gives enough extract for identification. Because of partial decomposition of the thioacid during the foregoing saponification, sulphides are produced and the above acidification and extraction should be carried out in a fiime cupboard. The ether extract can be evaporated to dryness on a water bath md examined by infrared or nuclear magnetic resonance spectroscopy or by both techniques, but, because of partial decomposition a better way of identification at least for the thioacid, is as follows ... 

An unusual method for the preparation of syndiotactic polybutadiene was reported by The Goodyear Tire Rubber Co. (43) a preformed cobalt-type catalyst prepared under anhydrous conditions was found to polymerize 1,3-butadiene in an emulsion-type recipe to give syndiotactic polybutadienes of various melting points (120—190°C). These polymers were characterized by infrared spectroscopy and nuclear magnetic resonance (44—46). Both the Ube Industries catalyst mentioned previously and the Goodyear catalyst were further modified to control the molecular weight and melting point of syndio-polybutadiene by the addition of various modifiers such as alcohols, nitriles, aldehydes, ketones, ethers, and cyano compounds. 

Despite the importance of solid-state nuclear magnetic resonance (NMR) spectroscopy for the characterization of solid catalysts, in situ studies related to photocatalysts are rare. Mills and O Rourke [59] monitored the selective photooxidation of toluene by in situ NMR using an NMR tube as the photoreactor. A Ti02 precursor paste was prepared by hydrolysis of titanium propoxide and following treatment at 228 °C. The obtained anatase-type titania was mixed with poly(vinyl alcohol). The obtained paste was coated on the walls of the NMR tube, rotated over night and calcined. In parallel, batch experiments were carried out. The reaction mixture containing the catalyst was directly placed into the tube, which was irradiated outside the spectrometer and then inserted into the NMR spectrometer. 

Carbon stable isotope ratio (CSIR) analysis of sugar utilizing an isotope ratio mass spectrometer (IRMS) is routinely used to detect the addition of cane sugar and corn syrup to most juices with the exception of pineapple. The inability of CSIR analysis to detect beet sugar in orange and apple juices because of metabolic similarities between adulterant and authentic products has required alternative methods, e.g., combination of IRMS and nuclear magnetic resonance (NMR) spectroscopy. The method requires the determination of five isotope ratios after fermentation of the juice the H/ H and iSq/ISo ratios of the fermentation water plus the total C/ C and H/ H ratios on the methyl and methylenic groups of the alcoholic distillate. 

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