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101.
Preparation of visible-light-responsive TiO2-xNx photocatalyst by a sol-gel method: analysis of the active center on TiO2 that reacts with NH3 总被引:5,自引:0,他引:5
Kuroda Y Mori T Yagi K Makihata N Kawahara Y Nagao M Kittaka S 《Langmuir : the ACS journal of surfaces and colloids》2005,21(17):8026-8034
Active reaction centers for ammonia on titanium oxyhydroxide were explored to direct the search for an efficient sol-gel method for the synthesis of a titanium oxynitride (TiO2-xNx) sample with an efficient responsiveness to the visible light constituting a main part of the solar spectrum. The results lead to the conclusion that the site giving IR bands at around 2195 cm(-1) for the adsorbed CO molecules at 300 K is a reactive site and behaves as Lewis acid site in the coordination environment of distorted five-coordinate Ti4+ ions. Ammonia molecules are adsorbed on such a site to form -NH2 and -OH species during the heat treatments at a temperature above 373 K, and they are ultimately incorporated into the TiO2 lattice as nitride through the dehydration at higher temperatures of up to 723 K, resulting in the formation of an anatase type of TiO2-xNx. 相似文献
102.
Yoshiro Kobayashi Toshinori Yamashita Katsuhiro Takahashi Hisashi Kuroda Itsumaro Kumadaki 《Tetrahedron letters》1982,23(3):343-344
Aryltrifluoromethylacetylenes were synthesized by an intramolecular Wittig reaction of trifluoroacetylarylidenephosphoranes, which were synthesized from arylmethyl halides. 相似文献
103.
104.
Nishimura K Higashi T Yoshimatsu A Hirayama F Uekama K Arima H 《Chemical & pharmaceutical bulletin》2008,56(5):701-706
The purpose of this study is to reveal whether Coenzyme Q10 (CoQ10) forms pseudorotaxane-like supramolecular complex with gamma-cyclodextrin (gamma-CyD). The poorly soluble complex of CoQ10 with gamma-CyD in water was prepared by the solubility method. The X-ray diffraction pattern of the CoQ10/gamma-CyD complex was different from that of the physical mixture, but almost the same as that of polypropylene glycol (PPG)/gamma-CyD polypseudorotaxane. Also, the differential scanning calorimetrical study and FT-IR study demonstrated the interaction between CoQ10 and gamma-CyD in the solid state. The 1H-NMR study and the yield study of the supramolecular complex of CoQ10 with gamma-CyD demonstrated that the stoichiometry was 5 : 1 (gamma-CyD : CoQ10). The dispersion rate of CoQ10 was markedly increased by the formation of the supramolecular complex with gamma-CyD, possibly due to submicron-ordered particle formulation. In fact, CoQ10 was found to form submicron-sized supramolecular particles with gamma-CyD, when prepared by the solubility method. Consequently, the present study showed that CoQ10 forms the pseudorotaxane-like supramolecular complex with gamma-CyD in water. 相似文献
105.
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107.
A Water‐Soluble Warped Nanographene: Synthesis and Applications for Photoinduced Cell Death 下载免费PDF全文
Dr. Hsing‐An Lin Dr. Yoshikatsu Sato Prof. Dr. Yasutomo Segawa Dr. Taishi Nishihara Nagisa Sugimoto Prof. Dr. Lawrence T. Scott Prof. Dr. Tetsuya Higashiyama Prof. Dr. Kenichiro Itami 《Angewandte Chemie (International ed. in English)》2018,57(11):2874-2878
Nanographene, a small piece of graphene, has attracted unprecedented interest across diverse scientific disciplines particularly in organic electronics. The biological applications of nanographenes, such as bioimaging, cancer therapies and drug delivery, provide significant opportunities for breakthroughs in the field. However, the intrinsic aggregation behavior and low solubility of nanographenes, which stem from their flat structures, hamper their development for bioapplications. Herein, we report a water‐soluble warped nanographene (WNG) that can be easily synthesized by sequential regioselective C?H borylation and cross‐coupling reactions of the saddle‐shaped WNG core structure. The saddle‐shaped structure and hydrophilic tetraethylene glycol chains impart high water solubility to the WNG. The water‐soluble WNG possesses a range of promising properties including good photostability and low cytotoxicity. Moreover, the water‐soluble WNG was successfully internalized into HeLa cells and promoted photoinduced cell death. 相似文献
108.
Dr. Takaaki Miyazaki Prof. Dr. Motonori Watanabe Prof. Dr. Toshinori Matsushima Dr. Ching-Ting Chien Prof. Dr. Chihaya Adachi Prof. Dr. Shih-Sheng Sun Prof. Dr. Hiroyuki Furuta Prof. Dr. Tahsin J. Chow 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(41):10677-10684
Heptacene ( 1 ) has been produced via a monoketone precursor, 2 , which was prepared from 1,2,4,5-tetrabromobenzene in nine steps in a total yield of 10 %. Compound 2 was converted to 1 quantitatively by heating at 202 °C. Heptacene exhibited high thermal stability in the solid state without any observable change over two months. To investigate the potential value of 1 as a material for p-type organic field-effect transistors (OFETs), top-contact OFET devices were fabricated by vacuum deposition of 1 onto a hexamethyldisilazane (HMDS)/SiO2/Si substrate. The best hole mobility performance was 2.2 cm2 V−1 s−1. This is the first report of stable heptacene being used in an effective device and examined for its charge carrier properties. 相似文献
109.
Takeshi Hoshikawa Xinming Huang Satoshi Uda Toshinori Taishi 《Journal of Crystal Growth》2006,290(2):338-340
Segregation phenomenon of Ga in Czochralski (CZ)–Si crystal growth has been investigated. The effective segregation coefficient, keff, of Ga was obtained for different growth rates by assuming the simple relationship between the concentration of Ga in Si crystal and the bulk Ga concentration in melt. Applying BPS theory to effective segregation coefficients which is valid for the melt-solidified fraction up to 0.38, an equilibrium segregation coefficient of Ga was obtained, k0=0.0079. 相似文献
110.
Yuki Yamamoto Dr. Hayato Sakai Dr. Junpei Yuasa Prof. Yasuyuki Araki Prof. Takehiko Wada Prof. Tomo Sakanoue Prof. Taishi Takenobu Prof. Tsuyoshi Kawai Prof. Taku Hasobe 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(12):4263-4273
A series of fluorescent “push‐pull” tetrathia[9]helicenes based on quinoxaline (acceptor) fused with tetrathia[9]helicene (donor) derivatives was synthesized for control of the excited‐state dynamics and circularly polarized luminescence (CPL) properties. In this work, introduction of a quinoxaline onto the tetrathia[9]helicene skeleton induced the “push–pull” character, which was enhanced by further introduction of an electron‐releasing Me2N group or an electron‐withdrawing NC group onto the quinoxaline unit (denoted as Me2N‐QTTH and NC‐QTTH, respectively). These trends were successfully discussed in terms of by electrochemical measurements and density functional theory (DFT) calculations. As a consequence, significant enhancements in the fluorescence quantum yields (ΦFL) were achieved. In particular, the maximum ΦFL of Me2N‐QTTH was 0.43 in benzene (NC‐QTTH: ΦFL=0.30), which is more than 20 times larger than that of a pristine tetrathia[9]helicene (denoted as TTH; ΦFL=0.02). These enhancements were also explained by kinetic discussion of the excited‐state dynamics such as fluorescence and intersystem crossing (ISC) pathways. Such significant enhancements of the ΦFL values thus enabled us to show the excellent CPL properties. The value of anisotropy factor gCPL (normalized difference in emission of right‐handed and left‐handed circularly polarized light) was estimated to be 3.0×10?3 for NC‐QTTH. 相似文献