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791.
Yusuke Ishigaki Takashi Harimoto Keisuke Sugimoto Luyan Wu Wenhui Zeng Deju Ye Takanori Suzuki 《化学:亚洲杂志》2020,15(7):1147-1155
When the 1,1,4,4‐tetraanilinobutadiene skeleton is attached with two halogenated aryl units at the 2,3‐positions, they undergo facile two‐electron oxidation to give stable dicationic dyes which exhibit a near‐infrared (NIR) absorption whereas the neutral dienes show only pale color. Therefore, a distinct electrochromic response with an absorption change in the NIR region is achieved, which is attracting considerable recent attention from the viewpoint of bioimaging. Herein, we demonstrate that the redox potentials of the 1,1,4,4‐tetraanilinobutadiene can be precisely controlled by the donating properties of the amino group on the aniline unit as well as the number of halogen atoms on the aryl units at 2,3‐positions on the butadiene. In contrast, the NIR absorption bands mainly depend on the number of halogen atoms irrespective to the donating properties of aniline unit. Thus, the hexaarylbutadiene skeleton is proven to be a versatile scaffold to develop less‐explored organic NIR electrochromic materials, whose redox and spectroscopic properties can be finely tuned by modifying/attaching the proper substituents. 相似文献
792.
Munechika Nakamura Yoshimi Tsukamoto Takuro Ueta Yoshihisa Sei Takanori Fukushima Kenji Yoza Kenji Kobayashi 《化学:亚洲杂志》2020,15(14):2218-2230
A 2 : 4 mixture of tetrakis[4‐(4‐pyridyl)phenyl]cavitand ( 1 ) or tetrakis[4‐(4‐pyridyl)phenylethynyl]cavitand ( 2 ) and Pd(dppp)(OTf)2 self‐assembles into a homocapsule { 1 2 ? [Pd(dppp)]4}8+ ? (TfO?)8 ( C1 ) or { 2 2 ? [Pd(dppp)]4}8+ ? (TfO?)8 ( C2 ), respectively, through Pd?Npy coordination bonds. A 1 : 1 : 4 mixture of 1 , 2 , and Pd(dppp)(OTf)2 produced a mixture of homocapsules C1 , C2 , and a heterocapsule { 1 ? 2 ? [Pd(dppp)]4}8+ ? (TfO?)8 ( C3 ) in a 1 : 1 : 0.98 mole ratio. Selective formation (self‐sorting) of homocapsules C1 and C2 or heterocapsule C3 was controlled by guest‐induced encapsulation under thermodynamic control. Applications of Pd?Npy coordination capsules with the use of 1 were demonstrated. Capsule C1 serves as a guard nanocontainer for trans‐4,4′‐diacetoxyazobenzene to protect against the trans‐to‐cis photoisomerization by encapsulation. A chiral capsule { 1 2 ? [Pd((R)‐BINAP)]4}8+ ? (TfO?)8 ( C5 ) was also constructed. Capsule C5 induces supramolecular chirality with respect to prochiral 2,2′‐bis(alkoxycarbonyl)‐4,4′‐bis(1‐propynyl)biphenyls by diastereomeric encapsulation through the asymmetric suppression of rotation around the axis of the prochiral biphenyl moiety. 相似文献
793.
Aoyama H Noguchi T Misawa T Nakamura T Miyachi H Hashimoto Y Kobayashi H 《Chemical & pharmaceutical bulletin》2007,55(6):944-949
We synthesized a series of compounds based on the potent tubulin-polymerization inhibitor 5-hydroxy-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione [5HPP-33 (3)], which is structurally derived from thalidomide (1), and investigated their inhibitory effects on tubulin polymerization. Direct interaction between 5HPP-33 (3) and alpha,beta-tubulin heterodimer protein was demonstrated by means of a surface plasmon resonance study. 相似文献
794.
Takanori Suzuki Ryuuichi Tamaki Eisuke Ohta Takashi Takeda Hidetoshi Kawai Kenshu Fujiwara Masako Kato 《Tetrahedron letters》2007,48(22):3823-3827
The spiro-acridan/acridinium-based dynamic redox pair (1/22+) transduces the electrochemical input into UV-vis and fluorescence spectra, whereas the 2,2′-bipyridine units in 1 works as a bidentate ligand for metal ions. X-ray structural analyses of this redox pair and the corresponding Zn-complexes [1-ZnI2/22+-Zn2+(OTf−)4] demonstrate drastic structural changes upon electron-transfer, thus metal binding properties are modified by redox reactions. 相似文献
795.
Let α and β be functions in ${L^\infty(\mathbb{T})}$ , where ${\mathbb{T}}$ is the unit circle. Let P denote the orthogonal projection from ${L^2(\mathbb{T})}$ onto the Hardy space ${H^2(\mathbb{T})}$ , and Q = I ? P, where I is the identity operator on ${L^2(\mathbb{T})}$ . This paper is concerned with the singular integral operators S α,β on ${L^2(\mathbb{T})}$ of the form S α,β f = αPf + βQf, for ${f \in L^2(\mathbb{T})}$ . In this paper, we study the normality of S α,β which is related to the Brown–Halmos theorem for the normal Toeplitz operator on ${H^2(\mathbb{T})}$ . 相似文献
796.
Takanori Iino Po-Lin Li Wen-Zhe Wang Jia-Huei Deng Yun-Chang Lu Fu-Jen Kao Yoichiroh Hosokawa 《Applied Physics A: Materials Science & Processing》2014,116(1):389-393
When an intense femtosecond laser is focused in a cell culture medium, shock wave, stress wave, and cavitation bubble are generated at the laser focal point. Cell–cell adhesion can be broken at the cellular level by the impacts of these factors. We have applied this breaking of the adhesion to an estimation of the cell–cell adhesion strength. In this application, it is important to identify which of these factors is the dominant factor that breaks the adhesion. Here we investigated this issue using streptavidin-coated microbeads adhering to a biotin-coated substrate as a mimic of the cell–cell adhesion. The results indicated that the break was induced mainly by the stress wave, not by the impact of the cavitation bubble. 相似文献
797.
Koga T Jiang N Gin P Endoh MK Narayanan S Lurio LB Sinha SK 《Physical review letters》2011,107(22):225901
We report the origin of the effect of nanoscale confinement on the local viscosity of entangled polystyrene (PS) films at temperatures far above the glass transition temperature. By using marker x-ray photon correlation spectroscopy with gold nanoparticles embedded in the PS films prepared on solid substrates, we have determined the local viscosity as a function of the distance from the polymer-substrate interface. The results show the impact of a very thin adsorbed layer (~7 nm in thickness) even without specific interactions of the polymer with the substrate, overcoming the effect of a surface mobile layer at the air-polymer interface and thereby resulting in a significant increase in the local viscosity as approaching the substrate interface. 相似文献
798.
Takanori Tsutaoka Koji ShimomuraAkira Tanaka 《Journal of magnetism and magnetic materials》2011,323(23):3147-3150
Magnetovolume effect in Nd7Rh3 single crystal has been studied by measuring the magnetostriction as a function of external magnetic field at 4.2 K. An irreversible magnetovolume effect having a negative remanent volume magnetostriction was observed when the external magnetic field was applied along the b-axis. The irreversible magnetostrictive effect takes place in the longitudinal magnetostriction along the b-axis. The remanent magnetostriction along the b-axis relaxes after removing external magnetic field for several hours and equilibrium state is stabilized. 相似文献
799.
800.
Surinder K. Mehta Yosuke Imai Hiroki Takumi Kinue Shibata Hiroyasu Sakamoto Takanori Takiue Hiroki Matsubara Makoto Aratono 《Colloid and polymer science》2013,291(11):2647-2652
The temperature-dependent conformational states of a monolayer film of ethylene glycol monododecyl ether (C12E1) at the air/water interface have been investigated using ellipsometry, surface tension, external reflection–absorption FTIR spectroscopy and two-dimensional infrared (2DIR) correlation analysis. The ellipticity coefficients and the entropy associated with C12E1 adsorption changed almost discontinuously at certain temperatures, which manifested the interfacial phase transitions. The phase transition and coexistence of two phases were further clarified using 2DIR correlation analysis with temperature perturbation. The asynchronous correlation maps revealed that both bands of asymmetric and symmetric C–H stretching vibration in one-dimensional IR were split into two components, which confirmed the coexistence of two phases at the interface. 相似文献