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91.
Acetophenone photo-sensitized addition of indene to cyclic fluoro-olefins (1,2-dichlorohexafluorocyclopentene-1, 1,2-dichlorotetrafluorocyclobutene-1 and hexafluorocyclobutene) gave the corresponding cycloadducts in satisfactory yields. The cycloadducts obtained predominantly had exo configuration.Some reactions such as reduction, oxidation, dechlorination and halogenation, of the cycloadducts were also studied. 相似文献
92.
Itsuki Shindachi Hiroshi Hanaki Ryo Sasai Tetsuya Shichi Tatsuto Yui Katsuhiko Takagi 《Research on Chemical Intermediates》2007,33(1-2):143-153
Diarylethene derivatives (DE) covalently bonded to silanol oxygens of layered silicate surfaces, i.e., magadiite (Mag), were synthesized and investigated for their photochromic behavior. The DE-Mag layered hybrids were found to undergo reversible color change by alternating UV and visible light irradiation. A more highly efficient, reproducible photochromic behavior was realized with DE-Mag than with a corresponding DE-Si possessing silyl substituents on DE in place of the Mag surface. Moreover, the present covalently bonded DE exhibited an improvement over DE hybrids incorporated in layered double hydroxide (LDH) clays, in which the repetitive photochromic behavior decreased during alternating irradiation, due to the accumulation of the photochemically inert parallel isomers of DE. 相似文献
93.
Kawasaki H Sasaki A Kawashima T Sasaki S Kakehashi R Yamashita I Fukada K Kato T Maeda H 《Langmuir : the ACS journal of surfaces and colloids》2005,21(13):5731-5737
Lyotropic phase behavior of the nonionic and the half-ionized oleyldimethylamine oxide (OlDMAO)/water systems was investigated using polarized light microscopy, small-angle X-ray diffraction, and differential scanning calorimetry. Nonionic OlDMAO formed isotropic micellar solution, nematic, hexagonal, cubic, and lamellar liquid crystalline phases as the surfactant concentration increased. In contrast, half-ionized OlDMAO (i.e., 1:1 mixture of the nonionic and the protonated species) had a greater tendency to form bilayer structures, and the phase diagram became quite similar to those of double-chained ionic surfactants rather than single-chained ones, despite the introduction of positive charges to the nonionic one. The preference of the bilayer structures in the half-ionized OlDMAO was interpreted in terms of the dimers stabilized by the hydrogen bond between the nonionic and protonated species. For alkyldimethylamine oxides with a saturated hydrocarbon chain (CnDMAO, chain length: n = 14, 16, and 18), the phase sequence of lyotropic liquid crystals was hardly affected by the protonation, but an elongation of the cylinders of the hexagonal phase was observed for the half-ionized C14DMAO. Consequently, it can be considered that the dominant bilayer formation of the half-ionized OlDMAO is attributed to the combined effect of the hydrogen-bonded dimer formation and the cis-double-bond configuration of the alkyl chain. 相似文献
94.
Sato H Tashiro K Shinmori H Osuka A Aida T 《Chemical communications (Cambridge, England)》2005,(18):2324-2326
Upon complexation with 4,4[prime or minute]-bipyridine, a cyclic dimer of a fused porphyrin zinc complex, having two pi-electronically coupled binding sites, shows a strong negative cooperativity in the second guest binding, to allow stepwise formation of 1 : 1 and 1 : 2 inclusion complexes. 相似文献
95.
Masao Tomoi Satoru Ishigaki Yasushi Arita Hiroshi Kakiuchi 《Journal of polymer science. Part A, Polymer chemistry》1988,26(8):2251-2261
Polystyrene-bound 4-(1-pyrrolidino)pyridine moieties were prepared by the reaction of chloromethylated polystyrene resins with pyrrolidinopyridine derivatives containing hydroxyl groups. The supported amines were effective catalysts for acylations of tert-alcohols or enols, acylrearrangements, and diester synthesis from epoxides and anhydrides. Some of the low ring-substituted (8–15%) catalysts exhibited high activity comparable to that of 4-(N,N-dimethylamino)pyridine, though the activity was a little lower than that of 4-(1-pyrrolidino)pyridine. The recovered catalysts can be re-used, except for acyl rearrangements, without significant decrease in activity. 相似文献
96.
Hiroshi Nishikawa Ei-Ichi Terada Eishun Tsuchida Yoshimi Kurimura 《Journal of polymer science. Part A, Polymer chemistry》1978,16(10):2453-2463
The (alkyl)-bis(dimethylglyoximato)pyridinecobalt attached to polychloromethylstyrene by a cobalt–carbon bond was prepared by the reaction of Co(II)(DH)2Py with polychloromethylstyrene in benzene. The fraction of p-vinylbenzyl·Co(DH)2Py introduced to the polymer was 8.1 and 2.1 mole %. The photodecomposition of the polymer-bonded cobaloxime was investigated by following the change of the visible spectrum. The rate constant kdec of the polymer-bonded cobaloxime was 1.1 × 10?2 sec?1 in benzene; it is one-fourth of that of its monomeric analog, benzyl·Co(DH)2Py. The kdec values of the cobaloximes were also measured in benzene–dimethyl sulfoxide mixed solvents, and the polymer effects were discussed. The dependence of the photodecomposition on energy of the irradiation light was investigated, and it was found that the absorption band near 470 nm is important for the photodecomposition of the cobalt–carbon bond. Spectroscopic measurements of the ligand exchange reaction of polymer-bonded cobaloxime with pyridine in dimethyl sulfoxide gave a larger equilibrium constant (1.2 × 104 liter/mole) than that of benzyl·Co(DH)2Py (9.4 × 102 liter/mole). The kinetic data of the ligand exchange reaction indicated that the larger equilibrium constant for the polymeric system is due to the smaller rate constant of the reverse reaction. The thermodynamic parameters were also obtained. 相似文献
97.
98.
Hossain MJ Yamasaki M Mikuriya M Kuribayashi A Sakiyama H 《Inorganic chemistry》2002,41(15):4058-4062
A new end-off type acyclic ligand with four hydroxyethyl arms, 2,6-bis[bis(2-hydroxyethyl)aminomethyl]-4-methylphenol [H(bhmp)], formed dinuclear cobalt(II) complexes [Co(2)(bhmp)(OAc)(2)]BPh(4) (1) and [Co(2)(bhmp)(OBz)(2)]BPh(4) (2). The complex 1.2.5CH(3)CN (C(50)H(62.5)BCo(2)N(4.5)O(9)) crystallizes in the monoclinic space group C2/c with dimensions a = 25.424(5) A, b = 13.376(2) A, c = 29.913(6) A, beta = 105.930(3) degrees, and V = 9781(3) A(3) and with Z = 8. X-ray diffraction analysis revealed a mu-phenoxo-bis(mu-acetato)dicobalt(II) core structure containing two octahedral cobalt(II) ions. Electronic spectra were investigated for 1 and 2 in the range 400-1800 nm, and the data were typical for the octahedral high-spin cobalt(II) complexes. Magnetic susceptibility was measured for 1 and 2 over the temperature range 4.5-300 K, and the data were analyzed well using our theoretical method. The best fitting parameters were kappa = 0.77, lambda = -116 cm(-1), Delta = 572 cm(-1), and J = -0.44 cm(-1) for complex 1 and kappa = 0.96, lambda = -93 cm(-1), Delta = 616 cm(-1), and J = -0.33 cm(-1) for complex 2. 相似文献
99.
Kazuyuki MiyashitaHidenobu Murafuji Hiroshi IwakiEito Yoshioka Takeshi Imanishi 《Tetrahedron》2003,59(26):4873-4879
As a second-generation pyridoxal model compound for cystathionine β-synthase, we designed a novel model compound having an ionophore function and an imidazole function, application of which to the β-replacement reaction with various thiols smoothly took place to give S-substituted cysteines. Peptides having a serine-O-carbonate residue at the N-terminal position were also converted to the corresponding peptides having an S-substituted cysteine residue under the catalytic conditions of the novel pyridoxal model compound. 相似文献
100.
Hiroshi Maruoka Kenji Yamagata Fumi Okabe Yukihiko Tomioka 《Journal of heterocyclic chemistry》2005,42(4):717-721
A series of cyclic sulfonium ylides 4a‐h reacted with titanium( IV ) chloride in the presence of triethyl‐amine to give the corresponding fused 2,3‐dihydro‐1H‐thieno[3,4‐b]pyrroles 5a‐h , via a ring opening and recyclization. In contrast, treatment of compounds 4a, 4b, 4e and 4f with titanium(IV) chloride, triethy‐lamine and dimethylamine hydrochloride gave the corresponding thiophenes 6a, 6b, 6e and 6f . Furthermore, compounds 6a and 6b easily underwent cyclization with sodium hydride to afford the corresponding 5a and 5b . 相似文献