Nuclear magnetic resonance spectroscopy aldehydes

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. 

Some of the cuticular lipids are also suitable for spectroscopic analysis. )3-Diketones absorb at 273 nm so that ultraviolet spectroscopy can be used (Tulloch, 1976). The functional groups of various fractions obtained by TLC can be confirmed by infrared analysis. Aldehydes and )8-diketones give useful shifts when examined by nuclear magnetic resonance and this technique can be made considerably more sensitive by the application of C-NMR for some wax components (Tulloch, 1976). 

Chapters 7 through 10 cover oxygen functionality in order of the increasing oxidation state of carbon—alcohols and phenols, ethers and epoxides, aldehydes and ketones, and acids and their derivatives. Brief mention of sulfur analogs is made in these chapters. Chapter 11 deals with amines. Chapters 2 through 11 treat every main functional group and constitute the heart of the course. Chapter 12 then takes up spectroscopy, with an emphasis on nuclear magnetic resonance (NMR) and applications to structure determination. This chapter handles the students question How do you know that those molecules really have the structures you say they have ... 

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