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1.
Bond IA Budding E Conway MJ Fenton KB Fujii H Fujii Z Fujimoto M Hasegawa H Hayashida N Honda M Hotta N Humble JE Kabe S Kasahara K Kifune T Masaike A Matsubara Y Mitsui K Miura Y Mori M Murakami K Muraki Y Nagano M Nakamura K Nakamura T Norris PM Ohashi Y Okada A Saito T Sakata M Sato H Shibata S Shima M Storey JR Tanimori T Teshima M Torii S Uchino K Watase Y Woodhams MD Yamamoto Y Yock PC Yuda T 《Physical review letters》1988,61(20):2292-2295
2.
The hydrogenolysisof 1-phenylbicyclo[4.1.0]heptane (1a), cis-1-phenyl-2-methylbicyclo[4.1.0]heptane (1b), 1-phenyl-7-azabicyclo[4.1.0]heptane (2) and 1-phenyl-7-oxabicyclo[4.1.0]heptane (3) was studied using Ni, Pd, Rh and Pt as catalysts. The hydrogenolysis of the C1C7 bond of 1a and 1b led to the selective formation of trans-1-phenyl-2-methylcyclohexane (4a) with retention of configuration. Compound 1a gave not only 4a but also phenylcycloheptane (6a), which is the product of C1C6 bond fission, and the ratio of 6a to 4a increased in the sequence: Ni ? Pd, Rh < Pt. No C1C6 bond fission was observed in the hydrogenolysis of 1b. These results can be explained by a mechanism involving the formation of the π-benzyl complex.trans-2-Phenylcyclohexylamine (8) was obtained stereoselectively in the hydrogenolysis of 2 over Raney Ni. This selective formation can be ascribed to the competition of “SN i” and “radical” processes. The Pd catalysed hydrogenolysis gave cis-2-phenylcyclohexylamine (9) as the main product, while the presence of sodium hydroxide promoted the formation of 8.Raney Ni catalysed hydrogenolysis of 3 yielded a mixture of phenylcyclohexane (13) and 2-phenylcyclohexanols (10 and 11). trans-2-Phenylcyclohexanol (10) was the dominant isomer; the hydrogenolysis resulted in the predominant configurational retention. Compound 13 was confirmed to be produced via 1-phenylcyclohexene (12). This deoxygenation may be explained by a mechanism involving the radical cleavage reaction of 3. The presence of sodium hydroxide led to the formation of cis-2-phenylcyclohexanol (11). The Pd catalysed hydrogenolysis also gave mainly 11.The difference in behaviour of cyclopropane, azidirine and epoxide we ascribe to the differences in the affinity for the catalyst and differences in the electronegativity between C, N and O atoms. 相似文献
3.
Hiroshi Mitsui Yuichi Shimizu 《Journal of polymer science. Part A, Polymer chemistry》1979,17(9):2805-2813
A kinetic study was made of the formation of hydrogen and trans-vinylene unsaturation in the radiolysis of polyethylene induced by γ rays with a dose rate of 6.35 × 105 rad/hr at 30–100°C in vacuo. The rates of the formation of hydrogen and trans-vinylene unsaturation were described by the zero-order formation kinetics with respect to each concentration combined with the first-order disappearance. The apparent rate constant for the formation of hydrogen increased gradually with rising irradiation temperature to give the activation energy of 0.6 kcal/mole. On the other hand, those for the disappearance of hydrogen and the formation and disappearance of trans-vinylene unsaturation were almost independent of temperature. The G values for crosslinking and main-chain scission were obtained from the gel data by using the Charlesby-Pinner equation, and the activation energy of 1.5 kcal/mole was given for both of them. On the basis of these results the reactions induced by γ rays in solid polyethylene were discussed. 相似文献
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Suzumura J Hosoya N Nagao S Mitsui M Nakajima A 《The Journal of chemical physics》2004,121(6):2649-2654
We have studied the electronic structures of several gas phase exohedral lanthanide (Ln)-C(60) clusters, Ln(n)C(60) (Ln=Pr, Ho, Tb, Tm, Eu, and Yb) with n=1-4, by photoionization spectroscopy of the neutrals and photoelectron spectroscopy of their anions. Both of the spectroscopic analyses reveal that most of the Ln atoms preferably take +3 oxidation states, while Eu atoms alone assume +2 oxidation states, and that C(60) accepts up to twelve donated electrons in Ln(n)C(60). An additional photoionization examination of the oxygen atom mixing into the Ln(n)C(60) clusters demonstrated that each oxygen atom reduces two electrons from C(60). This result implies that the number of accepted electrons in C(60) can be varied by a suitable choice of the number of Ln atoms and O atoms. 相似文献
6.
Synthesis and Self‐Assembly of Cyclic 2,7‐Anthrylene Ethynylene 1,3‐Phenylene Ethynylene Trimer with a Planar Conformation 下载免费PDF全文
Yuta Takaki Ryota Ozawa Dr. Takashi Kajitani Prof. Takanori Fukushima Prof. Masaaki Mitsui Prof. Kenji Kobayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16760-16764
Cyclic arylene ethynylene hexamer 1 , composed of alternating 2,7‐anthrylene ethynylene units and meta‐phenylene ethynylene units, was synthesized. It shows C3 symmetry and possesses a flat and rigid conformation with a large equilateral triangle‐like cavity. Macrocycle 1 self‐associates through π–π stacking interactions between the anthracene‐containing macrocyclic aromatic cores with indefinite‐association constant KE=6980 m ?1 in CDCl3 at 303 K. Macrocycle 1 also self‐assembles into π‐stacked nanofibers in the drop‐cast film. 相似文献
7.
To prepare cross‐linked silicone (silicone rubber) particles in an aqueous medium, we investigated two synthesis methods involving a miniemulsion system. The first method was based on cationic ring‐opening polymerization of cyclic siloxane, which is a common synthetic route for linear silicone oil and uses octamethylcyclotetrasiloxane (D4) as the monomer and dimeric D4 (bis‐D4) as the cross‐linker. Although this method produces silicone particles, the particles do not remain in the particulate state after drying because of low cross‐linking density. The polymerization mechanism of this method was also investigated, which proceeds under the ring‐opening reaction of D4 in monomer droplets and upon polycondensation of hydrolyzed D4, which occurs in the water phase (ie, outside the monomer droplets). This mechanism implied that introducing the cross‐linking structure into particles is difficult because of the low solubility of bis‐D4 in water. To overcome these difficulties, we demonstrated a second method of preparing silicone particles based on the thiol‐Michael addition reaction between thiol‐terminated silicone oil and triacrylate in miniemulsion systems. Transmission electron microscopy images indicated that the silicone particles obtained in the particulate state upon drying and the aggregates of these particles showed elasticity. 相似文献
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Anion photoelectron spectroscopy of acetonitrile cluster anions, (CH3CN)(-)(n) (n=10-100), successfully demonstrates the competitive coexistence of two different anionic species: a solvated electron and a solvent-bound valence anion. The distinctly different nature of these anions is revealed by hole-burning-type photoelectron spectroscopy and relative photodetachment cross section measurements. This unusual coexistence is attributed to the closely lying nature of their anionic states at just the number of solvent molecules sufficient to almost complete the first solvation layer. 相似文献