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doi: 10.1246/bcsj.35.1055pmid: N/A
The observed spectra of water of crystallization were compared with those of aluminum chloride hexahydrate and interpreted on the basis of the effects of aluminum-water coördination and hydrogen bonding O–H…O. The wagging and the rocking frequency were both much higher than is usual in water of crystallization. It was proposed that this result, together with other peculiarities, may have some connection with the coördination strength between aluminum and water.
doi: 10.1246/bcsj.35.1058pmid: N/A
The observed spectra of water of crystallization were interpreted on the basis of the effect of hydrogen bonding. It was proposed that at least two kinds of water molecules exist in the unit cell of the crystal. The corresponding two O–H…O distances were roughly estimated to be 3.01 and 2.58 Å respectively by the use of Glemser’s relationship between the stretching frequency and the hydrogen bond distance.
doi: 10.1246/bcsj.35.1060pmid: N/A
The basicities of the nitro-substituted benzoanthrones were measured. One nitro-substitution decreases the basicity of beazoanthrone by about two pK units, as in the case of nitrosubstituted aniline and anthraquinone. This is explained qualitatively not by the inductive effect but by the resonance effect of the nitro groups on the carbonyl group of benzoanthrone in such way as to estimate approximately the change of resonance energies in the cases of both hydrocarbons and their related quinones. The gradient of the straight line of pK plotted versus log(N∗N) in the case of nitro-substitution is greater than in the case of chlorosubstitution. This means that the contribution of the polarized structure in the ground state to resonance effect is greater in the case of the nitro-derivatives of benzoanthrone than in the case of the chloro-derivatives.
Okamura, Seizo; Katagiri, Keizo
doi: 10.1246/bcsj.35.1064pmid: N/A
Catalyzed styrene polymerization in the presence of azobisisobutyronitrile and telomer has been carried out to investigate the effects of the conversion of monomer and of the addition of catalyst on the degree of polymerization of polymer under the same conditions as in the previous report.The apparent degree of polymerization of polymer was obtained as a rather larger value than expected. This situation is qualitatively explained by the reactions of a catalyst fragment radical with telomer and with polymer freshly produced.
doi: 10.1246/bcsj.35.1067pmid: N/A
The electrostatic parts of van Laar coefficients for binary systems of polar and non-polar liquids were calculated, assuming that (1) the polar molecule is anisotropic in polarizability, (2) that the polar molecule is an ellipsoid, and (3) that the dipole is a point dipole and its position is not at the center of the molecule.The results were compared with the experimental results.The agreement between the experimental values and the calculated values based on the refined model cannot be said to have been improved compared with the previous results, in which the calculations were made based on the much simpler model in which the polar molecule was spherical and isotropic, and the dipole was at the center of the sphere.
doi: 10.1246/bcsj.35.1073pmid: N/A
Among various dyes, the dyes suitable for the sensitization of the polymerization of acrylonitrile have been determined. Acridine and xanthene dyes have been found to be the most effective.Using acridine yellow, one of the most effective, the dye-sensitized photopolymerization has been investigated in detail; it has been shown that the reaction has several features characteristic of heterogeneous polymerization, e.g., its order is higher than one-and-a-half on monomer concentration.Assuming the initiation process to be a direct interaction between excited dye and monomer, and assuming the unimolecular termination by occlusion of the propagating radicals, the kinetic data has been interpreted.
doi: 10.1246/bcsj.35.1078pmid: N/A
The photobleaching of acridine yellow has been studied in various vinyl monomers, such as acrylonitrile, vinyl acetate, styrene, α-methylstyrene and methyl methacrylate.It has been found that (a) the photobleaching is apparently different in featue depending on the type of monomer; (b) the absorption maximum of the dye in the reaction systems shifted rapidly to a shorter wavelength in the cases of both styrene and α-methylstyrene by the irradiation of light, while it did not in the cases of acrylonitrile, vinyl acetate and methyl methacrylate; (c) a new absorption maximum at a shorter wavelength may result from the production of a relatively stable intermediate from the dye and styrene.Considering also the effects of such quenchers as potassium iodide and hydroqinone on the photobleaching and the polymerization, it has been concluded that the interaction of the triplet state of the dye molecule with the monomers is responsible for both the bleaching and the polymerization.
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