4204-60-8Relevant academic research and scientific papers
Self-complementary [2]catenanes and their related [3]catenanes
Cabezon, Beatriz,Cao, Jianguo,Raymo, Francisco M.,Stoddart, J. Fraser,White, Andrew J. P.,Williams, David J.
, p. 2262 - 2273 (2007/10/03)
Three [3]catenanes with cavities large enough to accommodate aromatic guests have been designed and synthesized (yields = 5-20%) by means of kinetically controlled self-assembly processes. The X-ray structural analysis of one of three [3]catenanes confirmed the presence of a rectangular cavity (dimensions = 7 ×11 A) lined by π-electron-rich recognition sites and hydro-gen-bond acceptor groups. In spite of their apparently ideal recognition features, none of these [3]catenanes bind guests incorporating a π-electron-deficient bipyridinium unit. However, the template-directed syntheses of the [3]catenanes also produce, in yields of 2-23%, [2]catenanes incorporating a l,5-dioxynaphtho[38]crown-10 inter-locked with a bipyridinium-based tetracationic cyclophane. The X-ray structural analyses of two of these [2]catenanes revealed that a combination of [π...π] and [C-H...π] interactions is responsible for the formation of supramolecular homodimers in the solid state. 1H NMR spectroscopic investigations of the four [2]catenanes demonstrated that supramolecular homodimers are also formed (Ka= 17-31M-1, T= 185 K) in (CD3)2CO solutions. Dynamic 1H NMR spectroscopy revealed that the 1,5-dioxynaphtho[38]crown-10 and tetracationic cyclophane components in the four [2]catenanes and in the three [3]catenanes circumrotate (ΔGC? = 9-14 kcal mol-1) through each other's cavity in (CD3)2CO. Similarly, the 1,5-dioxynaphthalene and the bipyridinium ring systems rotate (ΔGc? =10-14 kcalmol-1) about their [O...O] and [N ... N] axes, respectively, in solution.
Process for preparing α,ω-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester
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, (2008/06/13)
A process for producing an α,ω-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its ester, that has a high Young's modulus and that is useful as a material for polyesters capable to form self-extinguishing fibers and films. Thus α,ω-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its ester is obtained by reacting α,ω-bis(phenoxy)alkane-4,4'-dicarboxylic acid or its ester with chlorine in the presence of a solvent selected from the group consisting of lower fatty acid having 2 to 6 carbon atoms, hydrocarbon chloride having 1 to 8 carbon atoms, and carbon chloride having 1 to 2 carbon atoms, in high yield.
RADIATION-INDUCED REDUCTION OF AROMATIC CARBOXYLIC ESTERS IN ALCOHOLIC SOLUTIONS
Sugimori, Akira,Yashima, Toshihiro
, p. 483 - 486 (2007/10/02)
Gamma-irradiation of aromatic carboxylic esters in alcoholic solutions brings about the reduction of the ester group to aldehyde, alcohol, α-ketoalcohol, and 1,2-glycol.The reduction is effected by solvated electrons and solvent-derived hydroxyalkyl radicals.
Process for preparing alkyl 4,4'-(ethylenedioxy)bis-benzoates
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, (2008/06/13)
Alkyl 4,4'-(ethylenedioxy)bis-benzoates having improved properties such as anti-oxidation and anti-coloration are prepared in high yield and selectivity by, at the first step, reacting an excess alkyl p-hydroxybenzoate with a recycling alkyl p-(2-chloro-ethoxy)benzoate with heating in the presence of an alkali carbonate and an inert organic solvent until almost said alkyl p-(2-chloroethoxy)benzoate is consumed to produce an alkyl 4,4'-(ethylenedioxy)bis-benzoate and at the second step adding ethylene dichloride to the reaction system and continuing the heating to produce an alkyl p-(2-chloroethoxy)benzoate which is recycled, and separating the alkyl 4,4'-(ethylenedioxy)bis-benzoate produced.
