Sonochemical effect on two new Ruthenium(II) complexes with ligand (E)-N-((6-bromopyridin-2-yl)methylene)-4-(methylthio)aniline precursors for synthesis of RuO2 nanoparticles

Two novel Ru(II) complexes [(η⁶-p-cymene)RuCl(L2)]PF₆ (R2) and [(η⁶-C₆H₆)RuCl(L2)]PF₆ (R4), with ligand (E)-N-((6-bromopyridin-2-yl)methylene)-4-(methylthio)aniline (L2), were synthesized and characterized by elemental analysis, ¹H NMR, ¹³C NMR and IR spectroscopy. Based on X-ray crystallography studies, complexes R2 and R4 have coordination environments with formulated (η⁶-p-cymene)Ru(N₂Cl) and (η⁶-C₆H₆)Ru(N₂Cl), respectively. The thermal stabilities of compounds R2 and R4 were studied by thermal gravimetric (TG) and differential scanning calorimetry (DSC). Thermal decomposition of these complexes was at 280 °C and 260 °C under air atmosphere respectively. The interaction of these complexes with calf thymus DNA (CT-DNA) was explored through electronic absorption spectra, fluorescence and redox behavior studies. The results showed that the complexes bind to CT-DNA with electrostatic interactions. Nanoparticles of RuO₂ were prepared by calcination of R2 and R4. Also the role of the ultrasound waves on the characteristics of the RuO₂ nanoparticles was studied. The nanoparticles were characterized by IR spectroscopy and X-ray diffraction (XRD). Also size and morphology of nanoparticles were studied by scanning electron microscopy (SEM).     

醋酸铜和多氮杂环配体配合物的低热固相合成

室温下 ,醋酸铜分别与 1,2 ,4 三氮唑和苯并三氮唑充分研磨 ,能发生固相配位反应 ,研磨过程有醋酸逸出 ,杂氮配体取代了醋酸与Cu (Ⅱ )配位形成混配配合物 ,元素分析表征表明产物的组成为Cu(C2 H2 N3) (Ac)·H2 O和Cu (C6 H4 N3) (Ac)·H2 O。红外光谱图显示了杂氮配体的 CN ,醋酸的 CO 和水的O—H特征吸收。固相反应为合成新配合物提供了一条快速、温和及不需溶剂的途径。     

NO dissociation pathways on Rh(1 0 0), (1 1 0), and (1 1 1) surfaces: A comparative density functional theory study

The chemisorption and dissociation pathways of NO on the Rh(1 0 0), (1 1 0), and (1 1 1) surfaces are studied by the plane-wave density functional theory (DFT) with CASTEP program. In addition, the electronic and geometrical effects that affect the NO dissociation reactions have been investigated in detail. The calculation results are presented as following: The effective activation energies of the best NO dissociation pathways on the Rh(1 0 0), the Rh(1 1 0), and the Rh(1 1 1) are 0.63, 0.66 and 1.77 eV, respectively. The activity of the Rh planes for NO dissociation is in the order of Rh(1 0 0) ≈ Rh(1 1 0) > Rh(1 1 1). The low dissociation barrier for Rh(1 0 0) and Rh(1 1 0) is associated with the existence of a lying-down NO structure which acts as a precursor for dissociation. By Mulliken population analysis and structure analysis, both electronic and geometrical effects are found to affect the NO dissociation reactions, but the geometrical effect exceed the electronic. The energy decomposition scheme has been used to provide further insight into the NO dissociation reactions. Based on the calculations, the interaction energy between N and O in the transition state on the Rh(1 1 1) is found much larger than that on the Rh(1 0 0) and the Rh(1 1 0). The major differences of should originate from the variation of the bonding competition effect.     

A valence band photoemission study of Pb adsorption on Rh(1 0 0) and Rh(1 1 0)

We have studied the adsorption of Pb on the Rh(1 0 0) and (1 1 0) surfaces by photoemission and low energy electron diffraction (LEED), and tested the chemical properties by adsorption of CO. Pb forms two distinct c(2 × 2) phases on Rh(1 0 0), according to the temperature of the substrate. The phase formed below about 570-620 K, denoted α-c(2 × 2), reduces the coverage of adsorbed CO but does not affect the valence band spectrum of the molecule. The phase formed above this temperature, denoted β-c(2 × 2), also reduces the coverage of adsorbed CO but the valence band spectrum of the adsorbed CO is strongly affected. The two phases are also characterised by a slightly different binding energy of the Pb 5d_5/2 level, 17.54 eV for the α phase and 17.70 for the β phase. The Pb/Rh(1 1 0) surface shows two ordered Pb induced phases, c(2 × 2) and p(3 × 1). CO adsorbs on the first with reduced heat of adsorption and with a valence band spectrum that is strongly altered with respect to CO adsorbed on clean Rh(1 1 0), but does not adsorb on the p(3 × 1) structure at 300 K. We compare the present results with previous results from related systems.     

83 K光系统Ⅱ核心复合物不同激发的荧光光谱学

在83 K低温下,利用稳态荧光光谱技术对光系统Ⅱ（PSⅡ）核心复合物中激发能的传递进行了研究,激励波长分别选择为436 nm,480 nm,495 nm和507 nm,得到4种波长激发下的稳态荧光光谱.经过比较发现其最大峰值所在的位置没有因激发波长的不同而发生改变,都在696 nm处,在不同激发波长下经过高斯解析获得不同的谱带.根据发射光谱与吸收光谱的对应性,反映了不同的光谱特性,说明在不同波长光的激发下,核心复合物中能量传递的途径不同.同时,可以分析出在核心复合物中,至少有Chl a670.4670,Chl a684.7,685.1683,Chl a689.0687,Chl a690.9,693.4,695.2,698.06904种Chl a组分参与了能量的传递.     

Dielectric properties and study of AC electrical conduction mechanisms by non-overlapping small polaron tunneling model in Bis(4-acetylanilinium) tetrachlorocuprate(II) compound

In the present work, the synthesis and characterization of the Bis(4-acetylanilinium) tetrachlorocuprate(II) compound are presented. The structure of this compound is analyzed by X-ray diffraction which confirms the formation of single phase and is in good agreement the literature. Indeed, the Thermo gravimetric Analysis (TGA) shows that the decomposition of the compound is observed in the range of 420–520 K. However, the differential thermal analysis (DTA) indicates the presence of a phase transition at T=363 k. Furthermore, the dielectric properties and AC conductivity were studied over a temperature range (338–413 K) and frequency range (200 Hz–5 MHz) using complex impedance spectroscopy. Dielectric measurements confirmed such thermal analyses by exhibiting the presence of an anomaly in the temperature range of 358–373 K. The complex impedance plots are analyzed by an electrical equivalent circuit consisting of resistance, constant phase element (CPE) and capacitance. The activation energy values of two distinct regions are obtained from log σT vs 1000/T plot and are found to be E=1.27 eV (T<363 K) and E=1.09 eV (363 K<T).The frequency dependence of ac conductivity, σ_ac, has been analyzed by Jonscher's universal power law σ(ω)=σ_dc+Aω^s. The value of s is to be temperature-dependent, which has a tendency to increase with temperature and the non-overlapping small polaron tunneling (NSPT) model is the most applicable conduction mechanism in the title compound.     

Toxic effects of copper (II) ions on bovine hemoglobin

In this paper, the toxic influence of copper ions (II) on bovine hemoglobin was investigated by the combination of ultraviolet-visible absorption, fluorescence, time-resolved fluorescence, synchronous fluorescence, and circular dichroism spectra. Driven by hydrophobic and electrostatic forces, copper ions (II) could interact with bovine hemoglobin to form bovine hemoglobin-copper ions (II) complex with one binding site. The binding constant (K) was 1.57?×?10⁴, 1.89?×?10⁴ and 2.11?×?10⁴?L/mol at 298, 304, and 310?K, respectively. The binding distance (r) was 4.24?nm. Fluorescence and time-resolved fluorescence spectra showed that bovine hemoglobin quenched by copper ions (II) was a static quenching process. Results of synchronous fluorescence spectra revealed that the microenvironment and the conformation of bovine hemoglobin were changed during the binding reaction. Data of circular dichroism spectra suggested that with the increasing concentration of copper ions (II), the secondary structure of bovine hemoglobin underwent a decrease in α-helix and alteration in backbone microenvironment. Copper ions (II) was thus evidenced to have a certain toxic effect on physical bodies.     

基于FPGA的高速数据传输系统设计与实现

为了满足国家重点专项“量子科学实验卫星”中“量子存储板”高速串行数据传输的测试要求,提出了一种以Nios II嵌入式处理器为控制核心,TLK2711、RS422、USB2.0和千兆以太网为传输接口的高速数据传输解决方案;系统采用TLK2711完成高速数据的串并转换,采用RS422完成命令和控制信号的传输,实现与“量子存储板”的高速数据传输;利用Xilinx公司Zynq-7000芯片独有的ARM+FPGA架构实现千兆以太网完成数据的高速传输,利用EXAR公司XR21V1414 USB转串口芯片实现命令、遥测等数据的传输;采用Labview编写上位机控制整个系统的运行,实现命令发送、指令解析、运行状态显示、数据帧产生、高速数据传输、解析和存储等功能;实测结果表明,此系统数据传输速率高达600 Mbps,满足高速串行数据传输的要求,且具有稳定性高、可靠性好等优点。     

利用红外光谱分析乙酸锌催化合成2,4-甲苯二氨基甲酸甲酯的反应机理

利用红外光谱技术研究了无水乙酸锌催化2,4-二氨基甲苯与碳酸二甲酯反应生成2,4-甲苯二氨基甲酸甲酯的甲氧基羰基化反应机理.结果表明,碳酸二甲酯羰基碳上的氧与无水乙酸锌中的Zn2+配位形成配合物,无水乙酸锌的结构由双齿型转变为单齿型,同时使DMC的羰基碳被活化.然后2,4-二氨基甲苯作为亲核试剂,其氨基进攻配合物中碳酸二甲酯上被活化的羰基碳原子,发生甲氧基羰基化反应,配合物中的Zn-O配位键断裂,生成2,4-甲苯二氨基甲酸甲酯和甲醇,并使无水乙酸锌的结构重新回到双齿型.