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1,8-Bis(diphenylmethylium)naphthalenediyl dications promoted oxidative coupling of various N,N-dialkylanilines to afford the corresponding para-coupled bisanilines, benzidines, in good to excellent yield. The dications were readily prepared from a cyclic ether precursor, derived from 1,8-dibromonaphthalene, via deoxygenation with a silylating reagent in 1,1,1,3,3,3-hexafluoro-2-propanol under anhydrous conditions. [reaction: see text] 相似文献
2.
Ryozo Takatsuka Terunobu Unishi Itaru Honda Toshio Kakurai 《Journal of polymer science. Part A, Polymer chemistry》1977,15(8):1785-1797
Aromatic polyimides were synthesized by polymerization of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 2-dialkylamino-4,6-dihydrazino-1,3,5-triazines by a solution polymerization method followed by cyclodehydration. The polyimides had number-average molecular weights over 13,000–16,000 or viscosity values of 0.23–0.65 dl/g. The x-ray diffraction diagram of polyimide I showed a crystal pattern, but the pattern became less pronounced with increasing length of the polymer side chain, and thus polyimide V showed a typical amorphous pattern. Study of the thermal stability of the polyimides by thermogravimetric analysis showed that a steep weight loss occurred in the range 380–410°C. Among the polyimides, I had only poor solubility in organic solvent, while IV and V were soluble even in general organic solvents such as tetrahydrofuran and dioxane. 相似文献
3.
Yoshio Kobayashi Hidekazu Kakinuma Daisuke Nagao Yasuo Ando Terunobu Miyazaki Mikio Konno 《Journal of nanoparticle research》2009,11(7):1787-1794
This article describes a method for silica coating of Co–Pt alloy nanoparticles prepared in the presence of poly(vinylpyrrolidone)
(PVP) as a stabilizer. The Co–Pt nanoparticles were prepared in an aqueous solution at 25–80 °C from CoCl2 (3.0 × 10−4 M), H2PtCl6 (3.0 × 10−4 M), PVP (0–10 g/L), and NaBH4 (4.8 × 10−3–2.4 × 10−2 M). The silica coating was performed for the Co–Pt nanoparticle colloid containing the PVP ([Co] = [Pt] = 3.0 × 10−5 M) at 25 °C in (1/4) (v/v) water/ethanol solution with tetraethoxyorthosilicate (TEOS) (7.2 × 10−5–7.2 × 10−3 M) and ammonia (0.1–1.0 M). Silica particles, which had an average size of 43 nm and contained multiple cores of Co–Pt nanoparticles
with a size of ca. 8 nm, were produced at 1.4 × 10−3 M TEOS and 0.5 M ammonia after the preparation of Co–Pt nanoparticles at 80 °C, 5 g/L PVP, and 2.4 × 10−2 M NaBH4. Their core particles were fcc Co–Pt alloy crystallites. Their saturation magnetization was 2.0-emu/g sample, and their coercive
field was 12 Oe. 相似文献
4.
Yasushi Aoki Terunobu Nakajyo Akira Tsunemi Jinfeng Yang Yasuhiro Okada Masafumi Yorozu Masafumi Hirose Fumio Sakai Akira Endo 《Research on Chemical Intermediates》2001,27(7-8):689-697
A compact pulse radiolysis system using a photocathode RF gun was installed at Sumitomo Heavy Industries. Some performance tests were conducted concerning the electron beam and the laser pulse. The energy and the per-pulse charge of the electron beam were measured to be 1.75 MeV max. and 1 nC. The fluctuation of the charge was restricted within 2%. The pulse widths of the electron pulse and the analyzing laser pulse were 20 ps and 15 ps, respectively. The timing jitter between electron pulse and the laser pulse was ±5.7 ps. Based on these measurements, the all-over time resolution can deduced to be about 25 ps. 相似文献
5.
Teruaki Mukaiyama Kazuya Takeuchi Hideki Jona Hisashi Maeshima Terunobu Saitoh 《Helvetica chimica acta》2000,83(8):1901-1918
A catalytic and stereoselective glycosylation of several glycosyl acceptors with β‐D ‐glycosyl fluoride was successfully performed in the presence of a catalytic amount of trityl tetrakis(pentafluorophenyl)borate (TrB(C6F5)4) or trifluoromethanesulfonic acid (TfOH). When TrB(C6F5)4 was used as a catalyst in the solvent pivalonitrile/(trifluoromethyl)benzene 1 : 5, the glycosylation proceeded smoothly to afford the glycosides in high yields with high β‐D ‐stereoselectivities (see Table 3). Further, the glycosylation by the armed‐disarmed strategy in the presence of this catalyst was established (see Table 4). Similarly, glycosylation catalyzed by the strong protic acid TfOH afforded the corresponding β‐D ‐glycosides in good‐to‐excellent yields on treating β‐D ‐ glycosyl fluorides having a 2‐O‐benzoyl group with various glycosyl acceptors including thioglycosides (see Tables 6 and 7). 相似文献
6.
Muhammad Javed Iqbal Rafaqat Ali KhanShigemi Mizukami Terunobu Miyazaki 《Journal of magnetism and magnetic materials》2011,323(16):2137-2144
Single-phase W-type hexaferrite, BaCo2Fe16−2x(ZrMn)xO27 (x=0.0-1.0), has been synthesized by the chemical co-precipitation technique. Mössbauer analysis indicates substitution of Zr ions on tetrahedral (4e and 4fIV) sites and Mn ions on the octahedral ‘4fVI site’ at low-doped concentration when the concentration is increased Mn ions but show preference for the octahedral ‘2b site’. The highest enhancement in the value of the room temperature resistivity of 2.82×109 Ω cm has been obtained by doping with Zr-Mn content of x=0.6. The dissipation factor increases from 6.49×103 to 9.97×103 at 10 kHz with the addition of Zr-Mn dopants. Such materials are potentially suitable for electromagnetic attenuation purposes, for microwave absorption and as radar absorbing material. High values of saturation magnetization (67 emu/g) and remanent magnetization (34.7 emu/g) are obtained for substitution level of x=0.4 making them suitable for data processing devices. 相似文献
7.
Hisatoshi Konishi Shun Hashimoto Terunobu Sakakibara Shingo Matsubara Yusuke Yasukawa Osamu Morikawa Kazuhiro Kobayashi 《Tetrahedron letters》2009,50(6):620-10412
Tetranitroazacalix[4]arenes have been synthesized by the nucleophilic aromatic substitution of 1,5-difluoro-2,4-dinitrobenzene with 1,3-diaminobenzenes. An X-ray crystal structure analysis revealed that the azacalixarenes adopt a non-symmetrical 1,3-alternate conformation, and the dinitrobenzene rings strongly conjugate with the bridging nitrogen atoms. In the 1H NMR spectrum (CDCl3, 30 °C), the tetraisopropyl derivative 3b displays a pair of diastereotopic methyl signals of the isopropyl groups in agreement with the frozen 1,3-alternate conformation on the NMR time scale. The free energy of activation () for the macrocyclic inversion was determined to be 87.5 kJ mol−1 by temperature-dependent NMR spectroscopy. 相似文献
8.
We present a diode-pumped, chirped-pulse Yb:S-FAP regenerative amplifier. This regenerative amplifier was developed as a first amplifier in an all-solid-state Yb:S-FAP laser system for laser-Compton X-ray generation. The amplifier delivers pulse energies above 24 mJ at a repetition rate of 50 Hz. Pulse compression reduces pulse widths to approximately 2.0 ps. 相似文献
9.
Various aryl 4-dialkylaminophenyl ethers were readily synthesized without heating in good yield from phenols and N,N-dialkyl-4-phenylthioanilines. This oxidative arylation of phenols was successfully promoted by a bis(diphenylmethylium)naphthalenediyl dication via ipso-substitution of the phenylthio group in the anilines through a radical process. 相似文献
10.
Naphthalene-1,8-diylbis(diphenylmethylium) exhibits a unique electron-transfer reduction behavior due to the close proximity of the two triarylmethyl cations, which form a C-C bond while accepting two electrons, leading to 1,1,2,2-tetraphenylacenaphthene. The preparation of the dication was readily accomplished under anhydrous conditions starting from a cyclic bis(triarylmethyl) ether, derived from 1,8-dibromonaphthalene. The process proceeded via deoxygenation accompanying the formation of a disiloxane on treatment with a silylating agent (Me3SiClO4 or Me3SiOTf) in 1,1,1,3,3,3-hexafluoropropan-2-ol. The dication was successfully employed for oxidative coupling of N,N-dialkylanilines at the para-position to afford the corresponding benzidines in good to excellent yield. 相似文献
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