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51.
Imamura T Zhang W Horiuchi H Hiratsuka H Kudo T Obi K 《The Journal of chemical physics》2004,121(14):6861-6867
A laser-induced fluorescence spectrum was observed in the 500-560 nm region when a mixture of 1,4-cyclohexadiene and oxalyl chloride was photolyzed at 193 nm. The observed excitation spectrum was assigned to the A (2)A(2)<--X (2)B(1) transition of the cyclohexadienyl radical c-C6H7, produced by abstraction of a hydrogen atom from 1,4-cyclohexadiene by Cl atoms. The origin of the A<--X transition of c-C(6)H(7) was at 18 207 cm(-1). From measurements of the dispersed fluorescence spectra and ab initio calculations, the frequencies of several vibrational modes in both the ground and excited states of c-C(6)H(7) were determined: nu(5)(C-H in-plane bend)=1571, nu(8)(C-H in-plane bend)=1174, nu(10)(C-C-C in-plane bend)=981, nu(12)(C-C-C in-plane bend)=559, nu(16)(C-C-C out-of-plane bend)=375, and nu(33)(C-C-C in-plane bend)=600 cm(-1) for the ground state and nu(8)=1118, nu(10)=967, nu(12)=502, nu(16)=172, and nu(33)=536 cm(-1) for the excited states. 相似文献
52.
Takayanagi T 《The Journal of chemical physics》2005,122(24):244307
Ab initio electronic structure calculations have been performed for (CH(3)CN)(2) (-) and (CH(3)CN)(3) (-) cluster anions using a diffuse basis set. We found both the dipole-bound structures and internal structures, where in the former structure an excess electron is mainly distributed on the surface of the cluster while an excess electron is internally trapped in the latter configuration. The optimized structures found for cluster anions were compared to those for neutral clusters. Potential-energy surfaces were also plotted as a function of appropriate internal coordinates in order to understand the interconversions of the optimized structures of clusters. The relative stabilities of the optimized confirmers have been discussed on the basis of the characteristics of these potential surfaces, relative energies, and electron vertical detachment energies. 相似文献
53.
Mitsuru Ueda Toshiyuki Suzuki Yoshio Imai Charles U. Pittman Easley Wallace 《Journal of polymer science. Part A, Polymer chemistry》1983,21(10):2997-3008
The kinetics of cyanomethyl methacrylate (CyMA) homopolymerization was investigated in acetonitrile with azobisisobutyronitrile as initiator. The rate of polymerization Rp was expressed by Rp = k[AIBN]0.49[CyMA]1.2 and the overall activation energy was calculated as 72.3 kJ/mol. Kinetic constants for CyMA polymerization were obtained as follows: kp/k = 0.10 L1/2s?1/2; 2fkd = 1.57 × 10?5s?. The relative reactivity ratios of CyMA(M2) copolymerization with styrene (r1 = 0.15, r2 = 0.29) and methyl methacrylate (r1 = 0.43, r2 = 0.75) in acetonitrile were obtained. Applying the Q-e scheme (in styrene copolymerization) led to Q = 1.64 and e = 0.98. The glass transition temperature Tg of poly(CyMA) was observed to be 91°C by thermomechanical analysis. Thermogravimetry of poly(CyMA) showed a 10% weight loss at 265°C in air. 相似文献
54.
Kunitaka Muramatsu Masaji Shimazu Junzo Tanaka Shigeo Horiuchi 《Journal of solid state chemistry》1981,36(2):179-182
Complex bismuth oxides with layered structure are prepared with a series of compositions in the system Bi2CaNb2O9-NaNbO3. It is found by X-ray powder diffraction that each compound is composed of more than two phases, which are described by a formula Bi2CaNan?2NbnO3n+3, e.g., in the sample with the nominal composition Bi2CaNb2O9 · 8NaNbO3, the phases with n = 6 to 8 appear predominantly. These phases are closely intergrown to each other. Moreover, high-resolution electron microscopy reveals that microsyntactic intergrowth frequently occurs in the phases with n > 5. The occurrence of the latter intergrowth is explained in terms of the bond length obtained. 相似文献
55.
Hiroyoshi Kamogawa Toshiyuki Sueki 《Journal of polymer science. Part A, Polymer chemistry》1985,23(7):1963-1972
p-Vinylphenylsulfonylnitromethane ( 3 ) was synthesized by the reaction of sodium p-styrenesulfinate with nitromethane. Free radical copolymerizations of 3 with styrene and N-vinyl-2-pyrrolidone provided soluble copolymers. Conversions of RCH2X (X = Br, OAc) with the copolymers as reagents proceeded in a different manner from the corresponding lowmolecular-weight compound, phenylsulfonylnitromethane, to afford RCOOH in addition to the expected RCH2CH2NO2 and RCH2COOH; no nitriles were formed. 相似文献
56.
Mori Toshiyuki Drennan John Wang Yarong Li Ji-Guang Ikegami Takayasu 《Journal of Thermal Analysis and Calorimetry》2002,70(2):309-319
Doped ceria (CeO2) compounds are fluorite type oxides that show oxygen ionic conductivity higher than yttria stabilized zirconia, in oxidizing
atmosphere. In order to improve the conductivity, the effective index was suggested to maximize the oxygen ionic conductivity
in doped CeO2 based oxides. In addition, the true microstructure of doped CeO2 was observed at atomic scale for conclusion of conduction mechanism. Doped CeO2 had small domains (10-50 nm) with ordered structure in a grain. It is found that the electrolytic properties strongly depended
on the nano-structural feature at atomic scale in doped CeO2 electrolyte.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
57.
Kenjiro Hattori Akira Kenmoku Tsukasa Mizuguchi Daisuke Ikeda Mamoru Mizuno Toshiyuki Inazu 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):9-16
A synthetic series of heptakis-galactose-branched cyclodextrins (termed CDs) having a longer spacer arm using two amino-caproic acids as an enlarging unit were prepared. Starting with heptakis-amino-β-CD or heptakis-amino-caproic-amide-β-CD, treated with galactosyl-glucono-amide-caproic acid, the new compounds heptakis (Gal-cap1)-CD (4) or heptakis (Gal-cap2)-CD (5) were obtained. The longer galactose spacer arm extremely favors the PNA association. The effect of branch length on K with PNA was enhanced up to 138-fold 3 as well as with DXR enhanced up to 81-fold. Hexakis (Gal-cap2)-CD (6) was prepared and the association constants with rat liver cells were observed to be 2.5 × 1010 M−1. A multi-high mannose type oligosaccharide branched CD (7) showed a large association constant with DXR up to 1.1 × 109 M−1. The two-dimensional map for the association constants of newly synthesized oligosaccharide-branched CDs toward lectin or liver cells versus the association constants toward a drug (doxorubicin) suggested a method of finding a better targeting drug carrier. The structural effect of the oligosaccharide-CDs showed that the number and length of the branch were dominant factors in designing for enhanced dual recognition. 相似文献
58.
A sensitive and selective high-performance liquid chromatographic method is described for the determination of a novel calcium antagonist, (+)-(R)-3,4-dihydro-2-[5-methoxy-2-[3-[N-methyl-N-[2-[(3,4- methylenedioxy)phenoxy]ethyl]amino]propoxy]phenyl]-4-methyl-3-oxo-2H- 1,4-benzothiazine hydrogen fumarate (sesamodil fumarate; JAN, SD-3211, I), and its N-desmethylated metabolite (II) in plasma. Compounds I and II and an internal standard were isolated from plasma by solid-phase and liquid-liquid extraction. The extract was chromatographed on a reversed-phase C18 column, and the compounds of interest were detected by dual coulometric electrodes operated in an oxidative screen mode. The limit of determination for both I and II was at least 0.4 ng/ml in plasma. The utility of the assay was demonstrated by determining plasma levels of I and II in five dogs administered an oral dose of 60 mg of the drug. 相似文献
59.
C.Akira Horiuchi Akinori Takeda Wen Chai Kishoh Ohwada Shun-Jun Ji T.Tomoyoshi Takahashi 《Tetrahedron letters》2003,44(52):9307-9311
A novel reaction of α-iodo ketone (α-iodocycloalkanone, α-iodo-β-alkoxy ester, and α-iodoacyclicketone) with irradiation under a high-pressure mercury lamp gave the corresponding α-hydroxyketone in good yields. In the case of α,α′-diiodo ketone, α,α′-dihydroxyketone which little has been reported until now was obtained. This reaction affords a new, clean and convenient synthetic method for α-hydroxy- and α,α′-dihydroxyketone. 相似文献
60.
Nabeshima T Saiki T Iwabuchi J Akine S 《Journal of the American Chemical Society》2005,127(15):5507-5511
Synthesis and binding behavior of a novel multi-responsive host 1, in which two esters, two polyether moieties, two urea sites, and two bipyridine units as ion binding sites are arranged on the calix[4]arene skeleton, is reported. 1 recognizes Na(+) and Ag(+) simultaneously and quantitatively and captures an anionic guest. The ability of 1 to recognize anions, including CF(3)SO(3)(-) and BF(4)(-), remarkably increases in a stepwise manner using Na(+) and Ag(+) as effectors. The enhancement of the K(a) eventually reaches factors of 1500 and 2000 for NO(3)(-) and CF(3)SO(3)(-), respectively, in the presence of both Na(+) and Ag(+), compared to the free 1. The regulation of binding of multiple ligands may be applicable to multistep cascade systems for the amplification of molecular events, and further studies in this field could provide insight applicable to more advanced molecular devices. 相似文献