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Yao J.-L.,Tongji University | Gao X.,Tongji University | Sun W.,Tongji University | Fan X.-Z.,Xian Modern Chemistry Research Institute | And 2 more authors.
Inorganic Chemistry | Year: 2012

Herein, we report a new strategy for developing an on-off-on molecular "light switch" by utilizing the pH value to control the "conformational switch" of G-quadruplex DNA. A novel ruthenium(II) complex with an emission enhancement factor of 150 was synthesized and introduced to detect the switch by the naked eye. The "light switch" can be repeatedly cycled off and on through the addition of H+ and OH-, respectively. The conformational transitions of G-quadruplex DNA in K+ solution at different pH values in the acidic region were evidenced by circular dichroism and fluorescence titrations. Computational calculations by applying density functional theory (DFT)/time-dependent DFT and molecular docking were also carried out to gain insight into the "light-switch" mechanism. © 2012 American Chemical Society.

Wang Q.-H.,Xian Modern Chemistry Research Institute
Huozhayao Xuebao/Chinese Journal of Explosives and Propellants | Year: 2011

The physicochemistry properties, detonation performance, safety performance, crystallization and freeze performance, cast quality of the representative melt-cast carrier explosives, such as TNT, 2,2,2-trinitroethyl-4, 4,4-trinitrobutyrate(TNETB), 3,4-dinitrofurazanfuroxan(DNTF),1,3,3- trinitroazetidine (TNAZ), 2,4-dinitroanisole (DNAN),3,4-dinitropyrazole(DNP), were introduced. Their advantage and shortage as carrier explosives were analyzed. The route of using advantage and overcomsing shortage was presented. Considering that TNT will be the primary carrier explosive when it was modified; the systematic research of TNETB is necessary; DNTF is practicable when its sensitivity to shock is reduced and its crystal is controlled; DNP is an expected carrier explosive. With 13 refernces.

Tian C.,North University of China | Nie W.,North University of China | Borzov M.V.,North University of China | Su P.,Xian Modern Chemistry Research Institute
Organometallics | Year: 2012

Thermolysis of 1-ethyl-3-methyl-1H-imidazolium tetrafluoroborate (1) and 1,3-dimethyl-1H-imidazolium hexafluorophosphate (3) under reduced pressure eliminates HF to furnish the BF 3 and PF 5 adducts of the corresponding Arduengo carbenes (2 and 4) in high yields. The intuitively anticipated imidazole N adducts with BF 3 and/or PF 5 arising from elimination of alkyl fluorides are not detected at all. These observations represent the first examples of a direct bond rearrangement of the type [C-H] + E-F → [C-E] + H-F (E = B, P). DFT computational studies suggest a single-step mechanism for the reaction 1 → 2 + HF. Lower yield thermolysis of a 1,2,3-trimethyl-1H-imidazolium hexafluorophosphate (11) into [(1,3-dimethyl-1H-imidazolium-2-yl)methyl]pentafluorophosphate (12) supports the generality of this transformation. © 2012 American Chemical Society.

Xue Y.-Q.,Taiyuan University of Technology | Yang X.-C.,Taiyuan University of Technology | Cui Z.-X.,Taiyuan University of Technology | Lai W.-P.,Xian Modern Chemistry Research Institute
Journal of Physical Chemistry B | Year: 2011

A monomolecular layer model of the surface phase of microdroplets was proposed, and the exact expression for Tolman length was derived in this paper. The Tolman lengths of water, n-pentane, and n-heptane were calculated by the expression, and the values are quite in agreement with the experimental values. By use of the Gibbs-Tolman-Kening-Buff equation, the exact relationship between the microdroplet surface tension and the radius is obtained, and the predicted values agree well with the simulated values. The results show that there is an obvious effect of the size of microdroplets (or nanoparticles) on the surface tension, and the surface tension decreases with decreasing droplet size. For the microdroplets of general liquid, only if their radius approaches or reaches 10-9 m does the effect become significant. © 2010 American Chemical Society.

Mao Z.,Hubei University of Medicine | Hu L.,Huazhong University of Science and Technology | Dong X.,Xian Modern Chemistry Research Institute | Zhong C.,Hubei University | And 2 more authors.
Analytical Chemistry | Year: 2014

Zn2+ plays vital roles in regulating physiological and pathological processes. A number of diseases are associated with the disruption of intracellular free Zn2+ homeostasis, and the relationship is still uncovered. Thus, it is important to monitor intracellular free Zn2+ ions in real time, which is still challenging due to the low content of intracellular free Zn2+. In this work, we report on the design and synthesis of a new two-photon (2P) fluorescent probe, QZn, based on quinoline derivative for intracellular free Zn2+. Theoretical calculations were carried out to rationalize the design. The probe displayed a moderate 2P action cross section value of 51 GM at 820 nm and up to 10-fold fluorescence enhancement upon Zn2+ binding. The detection limit of Zn2+ was 15.1 pM, which presented a pronounced sensitivity toward Zn2+ and indicated that QZn would be competent for detecting the low-content intracellular Zn2+. By using two-photon microscopy, QZn was capable of monitoring the fluctuation of intracellular free zinc ions in real time. © 2014 American Chemical Society.

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