酰氨基硫脲类新型分子钳受体的合成及其对氟离子的识别性能研究

本文设计并高产率合成了三种新型阴离子识别受体化合物,它们对F-的识别选择性较卤素其他阴离子的高。其对F-的识别性能通过紫外—可见光谱和核磁共振氢谱进行了检测,光谱数据表明,在DMSO溶液中受体与F-通过氢键相互作用形成1:1配合物。与以前我们报道的受体化合物相比,由于此类分子钳受体化合物具有更多的阴离子识别位点,因此具有更好地阴离子识别性能。     

Synthesis and Characterization of Copper(II) and Zinc(II) Tricyanomethanide (tcm) Complexes with Di(2‐pyridyl)amine (dpyam) as Co‐ligands: [Cu(dpyam)(tcm)2], [Cu(dpyam)(tcm)(OAc)] and Zn(dpyam)2(tcm)2

Three new transition metal tricyanomethanide complexes [Cu(dpyam)(tcm)₂] ( 1 ), [Cu(dpyam)(tcm)(OAc)] ( 2 ) and Zn(dpyam)₂(tcm)₂ ( 3 ) were synthesized and characterized by single crystal X‐ray diffraction analysis. In 1 each copper(II) atom is coordinated to three tcm anions and one dpyam molecule to form a square pyramide geometry. In 2 the coordination geometry around the central metal is also square pyramidal, and each copper atom is surrounded by two tcm anions, one dpyam ligand and one OAc. Both 1 and 2 display a µ_1,5‐tcm bridged infinite chain structure. In 3 each zinc(II) atom is coordinated by two tcm anions and two dpyam molecules to form a distorted octahedral geometry. Different from the former two complexes, 3 shows a mononuclear structure. Magnetic susceptibility measurement in the range 2–300 K indicates that there are weak antiferromagnetic couplings between adjacent copper(II) ions in 1 (J=?0.03 cm^?1) and 2 (J=?0.11 cm^?1) respectively.     

对苯二甲酸、2-(3-吡啶基)苯并咪唑配位聚合物的合成、晶体结构和发光

在水热条件下,对苯二甲酸(H2Bdc)和2-(3-吡啶基)苯并咪唑(3-PyHBIm)与Cd(NO3)2、Zn(NO3)2反应,得到配合物{[Cd(3-PyHBIm)(Bdc)(H2O)2](H2Bdc)1/2}n (1)、[Zn(3-PyHBIm)2(Bdc)(H2O)2]n (2)。单晶X-射线衍射结构分析表明,两个化合物均呈一维聚合结构,3-PyHBIm配体采用吡啶氮原子单齿配位。在配合物1中,对苯二甲酸根作为四齿配体,桥联Cd(II)离子,形成一维锯齿链状配位聚合物,两个水分子呈顺式配位。该化合物含有对苯二甲酸客体分子,通过强的氢键,构成三维超分子框架。在配合物2中,对苯二甲酸根作为双齿配体,结合Zn(II)离子,形成直线链状配位聚合物,两个水分子呈反式配位。两个配位聚合物都对热稳定,在固体状态下,呈蓝色发光。     

Synthesis and herbicidal activities of pyridyl sulfonylureas： More convenient preparation process of phenyl pyrimidylcarbamates

Four 4-monosubstituted pyrimidine pyridyl sulfonylureas were synthesized from pyridinesulfonamide and phenyl pyrimidylcarbamate and screened for herbicidal activities. We also reported a convenient preparation process of phenyl pyrimidylcarbamates from pyrimidineamine and phenyl chloroformate.     

Direct electron transfer of Mb on chitosan/single-wall carbon nanotubes film modified Au electrode and its interaction with cimetidine

Three methods were used to immobilize myoglobin (Mb) on chitosan/single-wall carbon nanotubes (SWNTs) film, and direct electrochemistry of the immobilized Mb was extensively investigated. Immobilized Mb displayed a couple of stable and well-defined redox peaks with the formal potential (E’) is at about −0.27 V (vs. SCE) in 0.1 M phosphate buffer solution (pH 7.0). The E′ was shifted linearly with pH in the range of 3.0 to 9.0 with a slope of −54.1 mV pH⁻¹, denoting that one-electron accompanies with one-proton transfer in electrode reaction process. The FT-IR spectroscopy and UV-vis spectroscopy showed that Mb on the film retained its secondary structure similar to its native state. The experimental results demonstrated that the immobilized Mb exhibited excellent electrocatalytic activity to reduction of cimetidine with a significant lowering of overpotential. The electrocatalytic current was proportional to the concentration of cimetidine over the range from 9.80 × 10⁻⁶ to 1.1 × 10⁻⁴ M; the detection limit is 8.40 × 10⁻⁶ M (signal-to-noise ratio of 3). The proposed method exhibits good sensitivity, stability and reproducibility. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 2, pp. 235–243. The text was submitted by the authors in English     

A Novel Electrochemical DNA Biosensor Fabricated with Layer‐by‐Layer Covalent Attachment of Multiwalled Carbon Nanotubes and Gold Nanoparticles

A novel DNA biosensor has been fabricated for the detection of DNA hybridization based on layer‐by‐layer (LBL) covalent assembly of gold nanoparticles (GNPs) and multiwalled carbon nanotubes (MWCNTs). The stepwise LBL assembly process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The hybridization events were monitored by differential pulse voltammetry (DPV) measurement of the intercalated doxorubicin, and the factors influencing the performance of the DNA hybridization was investigated in detail. The signal was linearly changed with target DNA concentration increased from 0.5 to 0.01 nM, and had a detection limit of 7.5 pM (signal/noise ratio of 3). In addition, the DNA biosensor showed an excellent reproducibility and stability under the DNA‐hybridization conditions.     

Ultrasensitive Voltammetric Detection of Trace Lead(II) and Cadmium(II) Using MWCNTs‐Nafion/Bismuth Composite Electrodes

Multiwall carbon nanotubes were dispersed in Nafion (MWCNTs‐NA) solution and used in combination with bismuth (MWCNTs‐NA/Bi) for fabricating composite sensors to determine trace Pb(II) and Cd(II) by differential pulse anodic stripping voltammetry (DPASV). The electrochemical properties of the MWCNTs‐NA/Bi composites film modified glassy carbon electrode (GCE) were evaluated. The synergistic effect of MWCNTs and bismuth composite film was obtained for Pb(II) and Cd(II) detection with improved sensitivity and reproducibility. Linear calibration curves ranged from 0.05 to 100 μg/L for Pb(II) and 0.08 to 100 μg/L for Cd(II). The determination limits (S/N=3) were 25 ng/L for Pb and 40 ng/L for Cd, which compared favorably with previously reported methods in the area of electrochemical Pb(II) and Cd(II) detection. The MWCNTs‐NA/Bi composite film electrodes were successfully applied to determine Pb(II) and Cd(II) in real sample, and the results of the present method agreed well with those of atomic absorption spectroscopy.     

Side-effect of ancillary ligand on electron transfer and photodynamics of a dinuclear valence tautomeric complex

A cobalt complex [[Co(dpqa)]2(dhbq)](PF6)3 ((PF6)3, dhbq = deprotonated 2,5-dihydroxy-1,4-benzoquinone, dpqa = di(2-pyridylmethyl)-N-(quinolin-2-ylmethyl)amine) was prepared and studied by X-ray diffraction, electrochemistry, ESR, thermally and photo-induced magnetic measurements; the results show that the ancillary ligand finely tuned structural factors as well as intermolecular interactions that affect the VT behavior.     

Enhanced Electrocatalytic Water Oxidation by Interfacial Phase Transition and Photothermal Effect in Multiply Heterostructured Co9S8/Co3S4/Cu2S Nanohybrids

The rational design of advanced nanohybrids (NHs) with optimized interface electronic environment and rapid reaction kinetics is pivotal to electrocatalytic schedule. Herein, we developed a multiple heterogeneous Co₉S₈/Co₃S₄/Cu₂S nanoparticle in which Co₃S₄ germinates between Co₉S₈ and Cu₂S. Using high-angle annular-dark-field imaging and theoretical calculation, it was found that the integration of Co₉S₈ and Cu₂S tends to trigger the interface phase transition of Co₉S₈, leading to Co₃S₄ interlayer due to the low formation energy of Co₃S₄/Cu₂S (−7.61 eV) than Co₉S₈/Cu₂S (−5.86 eV). Such phase transition not only lowers the energy barrier of oxygen evolution reaction (OER, from 0.335 eV to 0.297 eV), but also increases charge carrier density (from 7.76×10¹⁴ to 2.09×10¹⁵ cm⁻³), and creates more active sites. Compared to Co₉S₈ and Cu₂S, the Co₉S₈/Co₃S₄/Cu₂S NHs also demonstrate notable photothermal effect that can heat the catalyst locally, offset the endothermic enthalpy change of OER, and promote carrier migrate, reaction intermediates adsorption/deprotonation to improve reaction kinetics. Profiting from these favorable factors, the Co₉S₈/Co₃S₄/Cu₂S catalyst only requires an OER overpotential of 181 mV and overall water splitting cell voltage of 1.43 V to driven 10 mA cm⁻² under the irradiation of near-infrared light, outperforming those without light irradiation and many reported Co-based catalysts.     

Selective Formal Carbene Insertion into Carbon-Boron Bonds of Diboronates by N-Trisylhydrazones

Bisborylalkanes play important roles in organic synthesis as versatile bifunctional reagents. The two boron moieties in these compounds can be selectively converted into other functional groups through cross-coupling, oxidation or radical reactions. Thus, the development of efficient methods for synthesizing bisborylalkanes is highly demanded. Herein we report a new strategy to access bisborylalkanes through the reaction of N-trisylhydrazones with diboronate, in which the bis(boryl) methane is transformed into 1,2-bis(boronates) via formal carbene insertion. Since the N-trisylhydrazones can be readily derived from the corresponding aldehydes, this strategy represents a practical synthesis of 1,2-diboronates with broad substrate scope. Mechanistic studies reveal an unusual neighboring group effect of 1,1-bis(boronates), which accounts for the observed regioselectivity when unsymmetric 1,1-diboronates are applied.