Light-catalyzed Organic Reactions. I. The Reaction of Carbonyl Compounds with 2-Methyl-2-butene in the Presence of Ultraviolet Light

1954 ◽  
Vol 76 (17) ◽  
pp. 4327-4331 ◽  
Author(s):  
G. Büchi ◽  
Charles G. Inman ◽  
E. S. Lipinsky
Keyword(s):  
Ultraviolet Light ◽  
Carbonyl Compounds ◽  
Organic Reactions

Organic reactions using sodium hydrogentelluride. 3. The Reaction of Sodium Hydrogentelluride with .alpha.,.beta.-Unsaturated Carbonyl Compounds

1994 ◽  
Vol 59 (12) ◽  
pp. 3500-3502 ◽  
Author(s):  
Masakazu Yamashita ◽  
Yoshifumi Tanaka ◽  
Akishi Arita ◽  
Minoru Nishida
Keyword(s):  
Carbonyl Compounds ◽  
Organic Reactions ◽  
Alpha Beta

Gelation of Rubber Sols by Ultraviolet Light

1946 ◽  
Vol 19 (3) ◽  
pp. 632-644 ◽  
Author(s):  
R. Buckingham ◽  
G. V. Planer
Keyword(s):  
Ultraviolet Light ◽  
Experimental Work ◽  
Carbonyl Compounds ◽  
Theoretical Aspect ◽  
The Other ◽  
Other Hand ◽  
Industrial Manufacture ◽  
Quantitative Results

Abstract On exposure of rubber sols to ultraviolet light in the absence of oxygen, gels known as rubber photogels are formed under certain conditions. It has been found that on removing the solvent the rubber recovered exhibits properties somewhat similar to those obtained on vulcanization. The study of photogelation is of interest, apart from the purely theoretical aspect, because of its possible bearing on the problem of vulcanization, including the various sulfurless vulcanization reactions. Another important aspect is the bearing on the study of the aging of rubber, as well as on the industrial manufacture of rubber cements and solutions. Solvents used in the preparation of photogels are divided into active ones, i.e., those which condense with the rubber on irradiation, and nonactive ones. A number of accelerators are effective in the reaction ; among the most efficient of these are carbonyl compounds Buch as benzophenone, acetone, benzaldehyde, as well as benzoquinone, chloranil, eosin, etc. The nature of the reaction has not hitherto been satisfactorily explained, and a number of widely varying theories have been advanced in the literature. Some investigators regard the reaction as being a polymerization. Pummerer and Kehlen support this view because of the similarity to the photopolymerizations of styrene and isoprene, both of which are favored by the same accelerators as those used in the formation of photogels. Stevens, on the other hand, mentioned cyclization of the rubber molecules as a possible mechanism, and Asano drew attention to the possibility of a stereochemical rearrangement taking place in the molecule on irradiation, producing insolubility. In the experimental work to be described, the reaction was studied by determining the reaction curves under various conditions. As it has frequently been pointed out in the literature that inconsistent quantitative results have been obtained in the study of this reaction, particular importance was attached to developing methods which enabled reproducible results to be obtained.

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