5-二乙胺基-2-(吡啶-2’-亚氨甲基)苯酚的合成及其对Zn2+的识别

本文利用2-氨基吡啶与4-二乙胺基水杨醛反应合成了5-二乙胺基-2-(吡啶-2’-亚氨甲基)苯酚(探针L),对其结构进行了表征。在DMSO/Tris(6:4, v/v, pH =7.4)溶液中,探针L高选择性荧光“关-开”识别Zn₂₊,在365 nm紫外灯照射下,由无荧光变成蓝色荧光。实验表明,探针L与Zn₂₊的结合比为1:1,结合常数为2.6×10₃ L. mol_-1,检测限为 9.39×10_-7mol/L,pH适用范围为7-11,并可检测水样中的Zn₂₊。     

A New Thiosemicarbazone-Based Fluorescence “Turn-on” Sensor for Zn<Superscript>2+</Superscript> Recognition with a Large Stokes Shift and its Application in Live Cell Imaging

Selective fluorescence turn on Zn²⁺ sensor with long-wavelength emission and a large Stokes shift is highly desirable in Zn²⁺ sensing area. We reported herein the synthesis and Zn²⁺ recognition properties of a new thiosemicarbazone-based fluorescent sensor L. L displays high selectivity and sensitivity toward Zn²⁺ over other metal ions in DMSO-H₂O (1:1, v/v, HEPES 10 mM, pH = 7.4) solution with a long-wavelength emission at 572 nm and a large Stokes shift of 222 nm. Confocal fluorescence microscopy experiments demonstrate that L is cell-permeable and capable of monitoring intracellular Zn²⁺.

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Graphical Abstract We report a new thiosemicarbazone-based fluorescent sensor (L) for selective recognition of Zn²⁺ with a long wavelength emission and a large Stokes shift.

     

Photofragment translational spectroscopy of iodobenzene at 266 nm

The photofragmentation of C_6 H_5I at 266 nm is investigated on the nuiversal crossed molecular beam machine, and the translational spectroseopy as well as the angular distribution of I atom is measured. The results reveal that under the laser intensity of 10~8 W/cm~2 the single-phuton dissociation competes with multi-photon processes. In singlephoton dissociation the anisotropy parameter β is 0.4 and the average translational energy is only 1.04 keal/mol, which indicates that this process is a slow predissociation. In two-photon phutofragmentation the average translational energy is 51.64 kcal/mol, which accounts for about 35% of the available energy. Another photofragmentation channel is even more faster, whose peak in time-of-flight spectra corresponds to four or five photon absorptions. The branching ratio of these three channels is determined to be about 3: 3: 4.     

α-噻吩羧酸锌铕复合物的光谱性质

本文采用流变相反应法合成了具有很强红色发光的α－噻吩羧酸锌铕复合物,测定了样品的粉末Ｘ－射线衍射数据,热重曲线,紫外、红外光谱、激发和发射光谱,讨论了硫杂环和锌对铕离子特征发射的影响。α－噻吩羧酸锌铕复合物中锌能增加铕离子的特征发射强度,硫杂环能增强铕离子发光的效率。     

将SVRT模型应用到单原子多原子反应F+CH2 D2→CH2 D/CHD2 +DF/HF中

The semirigid vibrating rotor target（SVRT）model is applied for the reaction F+CH2D2→CH2D/CHD2+DF/HF. The time-dependent wave packet approach is also used in the calculation. Reaction probabilities,crosssections,and rate constants are calculated for the title reaction from the ground state of the reagent on the modified J1（MJ1）potential energy surface（PES）for both channels. Numerical calculation shows the oscillatory structures in the energy dependence of the calculated reaction probability. Those structures are generally associated with broad dynamical resonances. They are smooth in the energy dependence of integral cross-sections due to summation over partial waves. The calculated rate constants are in good agreement with the experimental measurement.     

Electronic structures and spectroscopic properties of rhenium (I) tricarbonyl photosensitizer: [Re(4,4'-(COOEt)2-2,2'-bpy)(CO)3py]PF6

The ground state and lowest triplet-state structures of [Re(4,4'-(COOEt)(2)-2,2'-bpy)(CO)(3)py]PF(6) photosensitizer (bpy=bipyridine, py=pyridine) have been studied with density functional theory (DFT). Time-dependent density functional theory (TD-DFT) was carried out to predict the photophysical properties of the photosensitizer. The effects of the solvents were evaluated using the conductor-like polarizable continuum (CPCM) method in dichloromethane, chloroform, acetonitrile, acetone, ethanol and dimethylsulfoxide. The electronic transition energies computed with BLYP, MPWPW91, B3LYP and MPW1PW91 functionals are compared with the experimental spectra. Based on the calculated excited energies, the experimental absorption maximum is assigned as metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT) mixed transition, and the luminescence originates from the lowest triplet state that is ascribed as the mixed transition of MLCT/LLCT.     

A Phenylbenzothiazole Derived Fluorescent Sensor for Zn(II) Recognition in Aqueous Solution Through “Turn-On” Excited-State Intramolecular Proton Transfer Emission

A highly selective and sensitive fluorescent Zn²⁺ sensor N-(2-(benzo[d]thiazol-2-yl)phenyl)-2-((pyridin-2-ylmethyl)amino)acetamide (1) that derived from 2-(2′-aminophenyl)benzothiazole has been developed. In aqueous solution (HEPES/CH₃CN=4/6, v/v, HEPES 20 mM, pH?=?7.4), sensor 1 displays highly selective recognition to Zn²⁺ over other metal ions with a distinct longer-wavelength emission enhancement. Sensor 1 binds Zn²⁺ through its amide form with a 1:1 binding stoichiometry, which switched on the excited-state intramolecular proton transfer (ESIPT). Graphical Abstract

A simple 2-(2′-aminophenyl)benzothiazole-based fluorescent “off-on” sensor for Zn²⁺ recognition in HEPES/CH₃CN(4/6, v/v, HEPES 20 mM, pH?=?7.4) solution through switching on ESIPT has been developed.     

Rhodium(III)- and Ruthenium(II)-Catalyzed Olefination of Isoquinolones

NH and N-protected isoquinolones undergo Rh(III)-catalyzed oxidative olefination at the 8-position. Complementary redox-neutral olefination of such isoquinolones using internal alkynes was achieved under ruthenium catalysis.     

An ICT-based strategy to a colorimetric and ratiometric fluorescence probe for hydrogen sulfide in living cells

We present a colorimetric and ratiometric fluorescent probe Cy-N(3) that exhibits a selective response to H(2)S. The probe employs a near-infrared cyanine as a fluorophore, and is equipped with an operating azide unit. It is readily employed for assessing intracellular H(2)S levels, and confocal ratiometric imaging is achieved successfully.