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991.
Xiaoyin Xiao Daniel Brune Jin He Stuart Lindsay Christopher B. Gorman Nongjian Tao 《Chemical physics》2006
We have synthesized cysteamine-terminated ferrocene molecules and determined the dependence of the electron transport properties of the molecules on their redox states by measuring the current through the molecules as a function of the electrode potential. The current fluctuates over a large range, but its average value increases with the potential. We attribute the current fluctuation and its increase with the potential to the switching of the molecules from low-conductance reduced state to high-conductance oxidized state. 相似文献
992.
Jun-Min Liu Qi-Yu Zheng Chuan-Feng Chen Zhi-Tang Huang 《Journal of inclusion phenomena and macrocyclic chemistry》2005,51(3-4):165-171
A new calix[4]arene-based fluorescent compound with two thio-ether groups as ionophore and one 3-alkoxy-2-naphthoic acid moiety as fluorophore has been designed, which exhibited highly selective binding of Cu 2+ over alkali, alkaline earth and some transition metal ions, including Co 2+, Ni 2+, Zn 2+, Mn 2+, Cd 2+, Pb 2+, Hg 2+, Ag +, Cu +, in CH 3OH–H 2O (2:1) within wide pH region. Moreover, the change of pH induces the consecutive quenching/revival of the fluorescence, with a concomitant distinct difference of the fluorescence quantum yield. In consequence, this system could be considered as a molecular switch. 相似文献
993.
A novel fluorescent chemosensor with two 5-nitro-salicylaldehyde groups at the upper rim of calix[4]arene has been synthesized. The chemosensor can effectively recognize copper(II) ion. This system could be considered as a molecular switch. By alternating the light irradiation of mixed solution formed by the host and Cu2+, off-on-off fluorescent switching is carried out. 相似文献
994.
995.
Properties of molecular switch triad compounds for photoinduced intramolecular energy transfer 总被引:1,自引:0,他引:1
He Tian Kongsheng Yang Xuehong Luo 《Journal of photochemistry and photobiology. A, Chemistry》1997,110(3):265-256
This paper reports the synthesis and transient absorption decay kinetics of several triad compounds, in which a sulfur aryl section is used as the spacer for intramolecular energy transfer (IET). After flash photolysis the producing sulfur radicals will provide an ‘energy trap’ to stop the IET process, after stopping flash photolysis the sulfur radicals reversibly recombine and the IET process recovers, and then a rapid photoinduced IET switchable function is realized. 相似文献
996.
The formation of heterobimetallic ruthenium(Ⅱ) complex was investigated by absorption and emission spectra. As an intercalator of DNA, the luminescent monometallic ruthenium(Ⅱ) complex [Ru(bpy)2tpphz]2+ could coor-dinate with Zn2+ to form the nonluminescent heterobimetallic complex [Ru(bpy)2(tpphz)Zn]4+. The emission in-tensity of complex decreased as increasing the amounts of Zn2+ and the luminescence was almost lost at the ratio of [Zn]/[Ru] of 1. After binding to DNA, the peripheral coordination site on the tpphz ligand remained accessible for Zn2+, the coordination occurred from the oppsite side of helix with respect to intercalated [Ru(bpy)2tpphz]2+ and the nonluminescent heterobimetallic complex was formed. On the other hand, the [Ru(bpy)2(tpphz)Zn]4+ also bound to DNA by intercalation and situated the region of the intercalated [Ru(bpy)2tpphz]2+ between the base pairs of DNA. The complex looked like a molecular nut (the Zn2+) and bolt (the [Ru(bpy)2tpphz]2+). 相似文献
997.
Fluorescence Switch Based on a Porphyrin-perylene Dyad 总被引:1,自引:0,他引:1
XinGuoYANG JingZhiSUN HanYingLI JianCAO MangWANG 《中国化学快报》2005,16(2):257-260
Upon excitation of porphyrin or perylene subunit, the porphyrin-perylene dyad exhibits reversible fluorescence emitting and quenching by formation and neutralization of the protonated porphyrin subunit, thereby providing a prototype of molecular fluorescence switch working in an expanded spectral range. 相似文献
998.
Some hymecromone derivatives containing chiral 1,1'-bi-2-naphthyl moiety were synthesized and their photodimerizations were investigated. It was found that fluorescence intensity and optical rotation of the new chiral hymecromone derivatives could be regulated by light. This property has potential significance for developing a new type of dual-mode molecular switch. 相似文献
999.
《Mendeleev Communications》2020,30(6):719-721
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1000.
在磁共振T/R开关和主动失谐线圈中广泛使用PIN管,由外部驱动器向PIN管提供驱动电源,控制其导通或截止,从而达到开关切换和线圈失谐的目的.因此,驱动器的性能直接影响T/R开关和线圈的性能.该工作提出了一种新的T/R开关驱动器设计方案.电路中门控信号与驱动电源互相隔离,同时包含了场效应管死区调整电路,提高了电路稳定性和灵活性.该电路开关切换时间可达500 ns,驱动电压和电流理论上分别可达400 V和10 A以上,具有快速、驱动能力强等特点.可用于快速T/R开关和主动失谐线圈的驱动、缩短死时间、减小发射线圈和接收线圈间的耦合. 相似文献