Hydrogenated homologues

Elastomeric styrene containing compounds, such as styrene-buta-diene-styrene block copol mriers, or styrene-isoprene-styrene block copolymers, including its hydrogenated homologues, all of them containing vegetal or even mineral oils in their formulations, can be made biodegradable (13). This is achieved by the admixture of brewer s yeast or yeast mother in amounts of 1-4%. 

X for this system was essentially negligible however, at higher temperatures X became negative. This was attributed to the copolymer effect rather than the existence of specific interactions. The poly butadienes were treated as random copolymers of 1,4- and 1,2-addition units, and there are deuterated and hydrogenous homologues in the mixture, i.e. there are four different types of monomer segment. A, B,C and D. Using the copolymer theory of ten Brinke et al. [30], then % can be written as ... 

Following Kirste and Ohm [ 1 ], the answer can be obtained from Small Angle Neutron Scattering with samples obtained from having deuterated backbone, mixed with their hydrogenated homologues ... 

Protonated methanes and their homologues and derivatives are experimentally indicated in superacidic chemistry by hydrogen-deuterium exchange experiments, as well as by core electron (ESCA) spectroscopy of their frozen matrixes. Some of their derivatives could even be isolated as crystalline compounds. In recent years, Schmidbaur has pre-... 

Formic acid exhibits many of the typical chemical properties of the aHphatic carboxyHc acids, eg, esterification and amidation, but, as is common for the first member of an homologous series, there are distinctive differences in properties between formic acid and its higher homologues. The smaller inductive effect of hydrogen in comparison to an alkyl group leads, for example, to formic acid = 3.74) being a considerably stronger acid than acetic acid... 

In quinoline and isoquinoline, the benzene ring is more receptive to fluorma-tion, its double bonds being saturated and the hydrogen atoms replaced in preference to those in the pyridine ring As with pyridine and its homologues, ring contraction takes place during fluorination with cesium tetrafluorocobaltate at... 

Notes on the preparation of secondary alkylarylamines. The preparation of -propyl-, ijopropyl- and -butyl-anilines can be conveniently carried out by heating the alkyl bromide with an excess (2-5-4mols) of aniline for 6-12 hours. The tendency for the alkyl halide to yield the corresponding tertiary amine is thus repressed and the product consists almost entirely of the secondary amine and the excess of primary amine combined with the hydrogen bromide liberated in the reaction. The separation of the primary and secondary amines is easily accomplished by the addition of an excess of per cent, zinc chloride solution aniline and its homologues form sparingly soluble additive compounds of the type B ZnCl whereas the alkylanilines do not react with sine chloride in the presence of water. The excess of primary amine can be readily recovered by decomposing the zincichloride with sodium hydroxide solution followed by steam distillation or solvent extraction. The yield of secondary amine is about 70 per cent, of the theoretical. 

The role of the methyl substituents in the diol host molecule was assessed by preparation of the homologues of 1 with hydrogen [ejco-2,ejco-6-dihydroxybicyclo-[3.3.1]nonane, (5)] and ethyl [exo-2,exo-6-dihydroxy-2,6-diethylbicyclo[3.3.1 Jnonane, (6)] substituents11 . Neither compound showed evidence of inclusion, or forma-... 

The diacyl peroxide and its lower homologues, though of relatively high thennal stability, are very shock-sensitive. Replacement of the hydrogen atoms adjacent to the carbonyl groups with alkyl groups renders the materials non-shock-sensitive. 

This, and the corresponding 5-chloro and 5-methoxy derivatives, tend to explode during vacuum distillation, and minimal distillation pressures and temperatures are recommended. This instability, (which was not noted for the homologues in which the hydrogen atom of the secondary amino group was replaced by alkyl) may be connected with the possibilty of isomerisation to the ac7-nitro iminoquinone internal salt species. 

F. Oxelfelt, P. Tamagnini, P. Lindblad (1998) Hydrogen uptake in Nostoc sp. strain PCC 73102. Cloning and characterization of a hupSL homologue. Archives of Microbiology, 169 267-274... 

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