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1.
Hisaya Tani Tuyoshi Konomi 《Journal of polymer science. Part A, Polymer chemistry》1968,6(8):2281-2293
The high molecular weight polymer of α-piperidone, which had been unobtainable with the use of alkali metal, trialkyl aluminum, or Grignard reagent as catalyst, was prepared with M–AlEt3, (where M is alkali metal), MAlEt4 or KAlEt3 (piperidone) as catalyst and N-acyl-α-piperidone as initiator. From the determination of the behavior of the solution viscosity of poly-α-piperidone in m-cresol at 30°C. the value of 0.27 for the Huggins constant was obtained. Examination of the correlation between the number-average molecular weight, determined by endgroup titration, and the intrinsic viscosity gave a somewhat small value for the endgroup COOH. This may be considered due to the consumption of N-acyl-α-piperidone by a propagating polymer in the course of polymerization. The thermal stabilities of the polyamides, nylons 4, 5, and 6, was in the order nylons 6 > 5 > 4 according to differential thermal and thermogravimetric analyses, Poly-α-piperidone, which has a reduced viscosity of 0.7, shows a melting point of 270°C.. which was expected from the zigzag pattern of the correlation between melting points and numbers of CH2 groups for polyamino-acid polymers. 相似文献
2.
Rahim MK Fukaminato T Kamei T Tamaoki N 《Langmuir : the ACS journal of surfaces and colloids》2011,27(17):10347-10350
The gliding motility of microtubules driven by kinesin on the surface of an azobenzene monolayer presenting lysine terminal groups is reversibly and repeatedly altered upon photoisomerization of the monolayer. 相似文献
3.
Fukaminato T Tanaka M Kuroki L Irie M 《Chemical communications (Cambridge, England)》2008,(33):3924-3926
Diarylethene derivatives with oxidized thiophene rings shift their absorption band to a shorter wavelength in the UV region upon photocyclization; no color change was observed during the photochromic reaction, and the invisible photochromism is advantageous for devices used under room light. 相似文献
4.
Soh N Ariyoshi T Fukaminato T Nakajima H Nakano K Imato T 《Organic & biomolecular chemistry》2007,5(23):3762-3768
A swallow-tailed perylene derivative including a triphenylphosphine moiety was synthesized and applied to the detection and the live-cell imaging of lipid hydroperoxides. The novel probe, named Spy-LHP, reacted rapidly and quantitatively with lipid hydroperoxides to form the corresponding oxide, Spy-LHPOx, which emits extremely strong fluorescence (Phi approximately 1) in the visible range (lambda(em) = 535 nm, 574 nm). Spy-LHP was highly selective for lipid hydroperoxides, and the addition of other reactive oxygen species (ROS) including hydrogen peroxides, hydroxyl radical, superoxide anion, nitric oxide, peroxynitrite, and alkylperoxyl radical, caused no significant increase in the fluorescence intensity. The probe exhibited good localization to cellular membranes and was successfully applied to the confocal laser scanning microscopy (CLSM) imaging of lipid hydroperoxides in live J774A.1 cells, in which lipid peroxidation was proceeded by the stimulation of 2,2-azobis(2-amidinopropane)dihydrochloride (AAPH). These findings establish Spy-LHP as a promising new tool for investigating the physiology of lipid hydroperoxides. 相似文献
5.
Soh N Yoshida K Nakajima H Nakano K Imato T Fukaminato T Irie M 《Chemical communications (Cambridge, England)》2007,(48):5206-5208
A fluorescent photochromic compound, composed of diarylethene, fluorescein and succinimidyl ester units, was developed for the controllable fluorescent labeling of biomolecules based on a small molecule. 相似文献
6.
Liu M You W Lei Z Zhou G Yang J Wu G Ma G Luan G Takata T Hara M Domen K Li C 《Chemical communications (Cambridge, England)》2004,(19):2192-2193
Y(2)Ta(2)O(5)N(2) is presented as a novel photocatalyst with high activity for water splitting under visible-light irradiation in the presence of appropriate sacrificial reagents; the activity for reduction to H(2) is increased by the incorporation of Pt or Ru as a co-catalyst, with a significant increase in production efficiency when both Pt and Ru are present. 相似文献
7.
Photochemically inactive diarylethene derivatives having a N-(O-hydroxyphenyl) group underwent photochromic reaction when they were esterified by the addition of acetic anhydride. 相似文献
8.
Nobuyuki Tanaka Chie Okabe Kenji Sakota Tuyoshi Fukaminato Tsuyoshi Kawai Masahiro Irie Alexander Goldberg Shinichirou Nakamura Hiroshi Sekiya 《Journal of Molecular Structure》2002,616(1-3):113-118
The fluorescence excitation and dispersed fluorescence spectra of the open-ring isomer of 1,2-bis(3-methyl-2-thienyl)perfluorocyclopentene have been measured in a supersonic free jet. No vibronic structure has been observed in the excitation spectrum. The intensity of fluorescence gradually increases with the excitation energy in the 25,500–28,700 cm−1 region, indicating that the geometry of the molecule substantially changes upon photoexcitation. The dispersed fluorescence spectrum is anomaly Stokes-shifted with respect to the excitation energy, suggesting that the S2(1B) state is initially excited followed by rapid internal conversion from the S2(1B) to S1(2A) state. The fluorescence is due to the S1(2A)–S0(1A) transition. Density functional theory calculations at the B3LYP/6-31G** level have been carried out to investigate stable conformations responsible for the observed spectra. 相似文献
9.
Polymerization of five-, six-, and seven-membered lactams by metallic potassium or MAlEt4 (where M is Li, Na, or K) as a catalyst and N-acyl lactam or diphenylketene as an initiator was carried out at temperatures below 80°C. By using MAlEt4 instead of a metallic potassium catalyst in the polymerization of α-piperidone the propagation was continued until the reduced viscosity of polymer reached a value of 0.9. The polymer obtained has a film-forming ability. The experimental results obtained in the gasometry suggest that MAlEt4 reacts with lactam to form such a complex of the type (where M is Li, Na, or K and X is an ethyl or 2-oxo-alkylene-imine group). The resulting complexes are considered to increase the solubility of catalyst and also to protect the polymer endgroups from side reactions by stabilizing the alkali metal as the complex. In addition, the mode of action of diphenylketene as an initiator was revealed by the facts that the corresponding N-diphenylacetyl lactam was obtained from the reaction of diphenyl ketene with lactam and N-diphenylacetyl lactam itself was useful for the polymerization of α-piperidone. 相似文献
10.
Nishida M Yoshimitsu H Okawa M Ikeda T Nohara T 《Chemical & pharmaceutical bulletin》2003,51(10):1215-1216
Two new 15,16-seco-cycloartane glycosides (1, 2) were isolated from Cimicifuga Rhizome. Their structures were determined by spectroscopic analysis. 相似文献