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Nylon-polystyrene microcapsules with immobilized ferroelectric liquid crystalline segments were prepared, and permeability control of an encapsulated core material was investigated under an external electric field. A ferroelectric liquid crystal monomer possessing both mesogenicity and chirality responded effectively to the external electrical field. Permeation of the material (oxprenolol) contained in the inner aqueous core of the microcapsules was enhanced under a weak electric field (2 V). Furthermore, the permeability of oxprenolol did not depend on the external electric field in the absence of the ferroelectric liquid crystal segments. To clarify the controlled-release mechanism of the core material, the light transmittance of the polymer membranes was quantitatively evaluated under an external electric field using a handmade polarized light transmittance apparatus.

The copolymer of N-isopropylacrylamide and 3-(acrylamido)phenylboronic acid (82:18, (M) over bar (n)=47000 g. mol(-1)) was prepared by free radical polymerization. The copolymer showed typical thermal precipitation behavior in aqueous solutions, its precipitation temperature (T-P) being increased from 23 to 32degreesC by increasing the pH from 6.5 to 9.7, because of ionization of the phenylboronate units. The pK(a) was evaluated as 8.9+/-0.1 from the effect of pH on T-P. At pH>9, i.e., in the anionic form of the copolymer, T-P was affected by a very low concentration of glucose (5.6 muM, DeltaT(P)=1-1.5degreesC), because of complex formation with a high binding constant. At a higher concentration of polyols (560 muM, pH>8) the increase of T-P was maximal for the copolymer complexes with fructose (7-10degreesC) and decreased in the order: fructose>glucoseapproximate tomannitol>pentaerythritol>galactose>Tris>glycerol. Di- and oligosaccharides (lactose, sucrose, and dextran) caused a slight increase of T-P at pH 7.5-8.7 while no effect was observed at pH>9. Isothermal dissolution of the copolymer suspension in water (27degreesC, pH 8.5) was possible in the. presence of fructose or mannitol but required higher concentrations (1.4-3.6 x 10(3) muM) as compared to those which enabled the shift of T-P in the soluble copolymer. The dissolution rate increased with fructose concentrations. (Less)

The photoamination of 1,1-diphenylpropene (1a) with ammonia and some primary alkylamines in the presence of p-dicyanobenzene gave the corresponding N-substituted 2-amino-1,1-diphenylpropane (2a–e) along with the formation of 3-methyl-4,4-diphenylbutanenitrile (3a), 1,1-diphenylpropane (4a), 3,3-diphenylpropene (5), and diphenylmethane (6). In the case of 1,1-diphenylethene (1b), N-substituted 1-amino-2,2-diphenylethane (2f–h), 4,4-diphenylbutanenitrile (3b), and 1,1-diphenylethane (4b) were produced. In photoamination with t-butylamine in acetonitrile, 3a and 3b were mainly formed as a consequence of the incorporation of acetonitrile to 1a and 1b. The photoamination of 1-phenyl-3,4-dihydronaphthalene (1c) with isopropylamine or t-butylamine gave cis- and trans-N-substituted 1-phenyl-2-amino-1,2,3,4-tetrahydronaphthalenes (15 and 16) in a ratio of ca. 8:2. The mechanism of photoamination is discussed in terms of a photochemical electron transfer of 1 to p-dicyanobenzene followed by a nucleophilic addition ...

Photoamination of 9-methoxyphenanthrene (1) with ammonia in the presence of m-dicyanobenzene (DCNB) gives cis- and trans-9-amino-10-methoxy-9,10-dihydrophenanthrene (6a, b) in a ratio of 75 : 25. The stereochemistry of 6a has been confirmed by X-ray crystallographic analysis of its acetamide. The photoamination of 1 with isopropylamine and 9-ethoxyphenanthrene (2) with tert-butylamine gives exclusively N-substituted cis-9-amino-10-alkoxy-9,10-dihydrophenanthrene. Also, the photoamination of phenanthrene (4) and anthracene (5) proceeds with trans addition of ammonia with high selectivities. The photoamination proceeds by nucleophilic addition of amine to the cation radical of the arene, generated from photochemical electron transfer to DCNB. The resulting aminated cation radicals undergo reduction by an anion radical of DCNB, followed by protonation to give final products. Selective trans additions of ammonia and alkylamines to arenes are suggested to arise from the protonation of the aminated anion.