Cyclometalated Platinum(II) Complexes with Donor-Acceptor-Containing Bidentate Ligands and Their Application Studies as Organic Resistive Memories

A series of heteroleptic cyclometalated platinum(II) complexes, [Pt(C^N)(O^O)], ( 1 – 10 ) with various donors and acceptors has been synthesized and characterized by ¹H NMR spectroscopy, elemental analyses, infrared spectroscopy and mass spectrometry. The X-ray structure of 2 has also been determined. The electrochemical and photophysical properties of the platinum(II) complexes were studied. These experimental results have been supported by computational studies. Furthermore, two of the complexes have been employed as the active material in the fabrication of resistive memory devices, exhibiting stable binary memory performance with low operating voltage, high ON/OFF ratio and long retention time.     

Amorphous/Crystalline Hetero-Phase TiO2-Coated α-Fe2O3 Core–Shell Nanospindles: A High-Performance Artificial Nitrogen Fixation Electrocatalyst

Electrochemical nitrogen fixation techniques have emerged as a promisingly sustainable approach to face the challenge associated with nitrogen activation of ammonia synthesis by the Haber–Bosch process under ambient conditions. Herein, the performance of electrocatalytic nitrogen reduction for the production of α-Fe₂O₃ nanospindles coated with mesoporous TiO₂ with different crystallinity [denoted as α-Fe₂O₃@mTiO₂-X (X=300, 400, and 500 °C)] were investigated. The as-prepared α-Fe₂O₃@mTiO₂-400 composite exhibits a large NH₃ yield (27.2 μg h⁻¹ mg_cat.⁻¹) at −0. 5 V vs. the reversible hydrogen electrode and a high Faradaic efficiency (13.3 %) in 0.1 m Na₂SO₄, with excellent electrochemical durability. This work presents a novel avenue for the rational design of efficient unique hetero-phase nanocatalysts toward sustainable electrocatalytic N₂ fixation.     

Medicinal Applications of Metal Complexes Binding to Biological Macromolecules

Biological macromolecules present in living organisms, like proteins, DNA, have many metal-binding sites. As a consequence, coordination compounds can react with such cellular components, displaying possible toxic effects, or they also may have beneficial applications. So metal ions and compounds not only are essential for life in e.g. dioxygen transport, or biocatalysis, but they can also be used for controlled toxicity in medicinal applications. Well-known examples are the application of gold compounds in arthritis treatment, bismuth compounds for ulcer healing, and silver compounds for open skin protection. However, only in a few cases details of the mechanist are known, and if so, the biological macromolecules play a key role. Transition-metal coordination compounds that have metal-ligand exchange rates comparable to cell-division processes, i.e. in particular Pt and Ru, often appear to be highly active in killing cancers, as seen from the study of several cancer cell lines. Classical examples, like cisplatin, and new examples of Pt and Ru compounds will be discussed in some detail, with a focus on their binding to the DNA biomacromolecule. The classical compound cis-diamminedichloridoplatinum(II), often abbreviated as cisplatin, and its first-generation derivatives are known to bind to several biomacromolecules in a specific way, and eventually bind at DNA. Four important examples are shown in the figure. However, on its way to DNA other cellular components, like proteins and peptides might be intermediates before the final target is reached. Other metal-containing drugs, like Ru compounds, that show anti-cancer activity have a less well-known mode of action. Molecular-based mechanistic studies may result in improved clinical administration protocols.     

介观结构氮掺杂碳纳米笼负载铂-钌合金催化剂的优异甲醇电氧化性能

利用氮掺杂碳纳米笼（hNCNC）的高比表面积及掺杂氮原子的锚定作用,方便地将约3 nm的Pt-Ru合金纳米粒子均匀地负载在hNCNC表面,制得了Pt和Ru比例可调的Pt-Ru/hNCNC双金属合金催化剂.这些催化剂展现出优异的甲醇催化氧化活性和稳定性,且具有良好的抗CO中毒能力,显著优于Pt/hNCNC和商业PtRu/C等对照组催化剂.其优异的电化学性能可归因于以下因素的协同作用：（1） Pt-Ru合金的双功能机制增强了催化剂的CO氧化脱附能力从而使活性位重新暴露,（2） hNCNC的氮掺杂及高比表面积有利于获得粒径小且均匀的合金纳米粒子,（3） hNCNC的多尺度分级孔结构有利于甲醇等参与反应物质的传输.     

嵌段共聚物模板法一步制备WC/C基底电极材料

以酚醛树脂作为碳源,采用嵌段共聚物模板法一步制备新型有序介孔碳化钨/碳（WC/C）纳米颗粒. WC/C颗粒的比表面积为414 m²·g^-1,表面的平均孔径约为38 nm,处于介孔范围内（2 ~ 50 nm）. 通过调节树脂预聚时间以及碳化温度等条件制备出结构形貌较优的WC/C复合材料,并探讨了材料形成机理. 使用X射线衍射、扫描电镜、透射电镜及氮气吸脱附等方法表征了复合材料的结构. 将贵金属铂负载于WC/C表面制备得新电催化材料Pt-WC/C,使用循环伏安法和计时电流法对Pt-WC/C复合材料的电化学性能进行检测,并与商用碳载铂（Pt/C）材料进行对比. 测试结果发现,Pt-WC/C对甲醇的电催化活性以及稳定性等方面都表现出优于商用Pt/C材料的活性,这主要归功于碳化钨高度分散于碳表面.     

ICP-AES测定铂金饰品抛光灰中铂、钯、金和银

提出一种 ICP- AES快速测定铂金饰品抛光灰中铂、钯、金、银的分析方法。 5 g样品经灰化处理后 ,王水提取 ,直接测定 ,该方法的检出限 Pt、Pd、Au、Ag分别为 4 6 .5、4 2 .3、10 .4和 5 .1ng·m L-1。回收率为94 .2 %— 10 3.5 %之间。相对标准偏差为 2 .8%— 4 .4 %。     

流动注射-分光光度法测定助燃剂中铂

王水溶解助燃剂中的铂 ,原子吸收分光光度计为检测器 ,流动注射 -氯化亚锡分光光度法测定铂含量 ,用于 CO助燃剂中铂的测定 ,结果与理论值一致     

Platinum complexes of malonate-derived monodentate phosphines and their application in the highly chemo- and regioselective hydroformylation of styrene

Neutral complexes of the formula PtCl₂L₂ (where L = diethyl 2-diphenylphosphino-malonate (1), diethyl 2-methyl-2-diphenylphosphinomalonate (2), dibenzyl 2-diphenylphosphinomalonate (3), 1,3-dihydroxy-2-methyl-2-diphenylphosphinopropane (4)) were prepared. These proved to be precursors to active catalysts for the hydroformylation of styrene. The platinum-containing catalytic systems prepared from ligand 4 provided the highest activity, while the platinum compounds prepared from other ligands all showed similar levels of reactivity to each other. The matching of high chemo- and regioselectivities were observed in most cases. Surprisingly, the complexes were practically inactive in imidazolium-type ionic liquids. ³¹P NMR studies on the PtCl₂L₂ complexes revealed that the stereoselectivity of the cis/trans geometrical isomers is strongly dependent on the structure of the ligand.     

Syntheses and structures of overcrowded silanedichalcogenols and their applications to the syntheses of silanedichalcogenolato complexes

Overcrowded silanedichalcogenols Tbt(Mes)Si(EH)(E′H), such as silanedithiol (E = E′ = S), hydroxysilanethiol (E = O, E′ = S) and hydroxysilaneselenol (E = O, E′ = Se), bearing an efficient combination of steric protection groups, Tbt and Mes (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, Mes = 2,4,6-trimethylphenyl), were synthesized and isolated as air- and moisture-stable crystals, and their structures were fully characterized by spectroscopic and elemental analyses together with X-ray crystallographic analyses. The results of IR spectroscopy and the X-ray structural analyses suggested that these compounds exist as monomers without any intra- and intermolecular interactions such as hydrogen bonds even in the solid state and in solution. Novel four-membered-ring compounds, such as Tbt(Mes)Si(μ-S)₂PnBbt and [Tbt(Mes)Si(μ-E)(μ-E′)ML_n] [E, E′ = O, S, Se; Pn = Sb, Bi; Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl; ML_n = Pd(PPh₃)₂, Pt(PPh₃)₂, Ru(η⁶-benzene)] were synthesized by utilizing the silanedichalcogenols as key building blocks. The molecular structures of these newly isolated compounds were determined by NMR spectroscopic data together with X-ray crystallographic analyses.     

Harvesting solar energy using conjugated metallopolyyne donors containing electron-rich phenothiazine-oligothiophene moieties

A new family of soluble, solution-processable metallopolyynes of platinum(II) functionalized with electron-rich phenothiazine-oligothiophene rings and their corresponding dinuclear model complexes were synthesized and characterized. The organometallic polymers show different degrees of absorption capabilities in the solar spectral region, rendering some of them good electron donors for fabricating bulk heterojunction polymer solar cells by blending with a methanofullerene electron acceptor. The influence of the number of thienyl rings along the polymer chain on the optical and photovoltaic properties of these metallopolymers was studied. At the same donor:acceptor blend ratio of 1:4 or 1:5, the light-harvesting capability and solar cell efficiency notably increase as the number of thienyl rings is doubled. Photoexcitation of the polymer solar cells results in a photoinduced electron transfer from the π-conjugated metallopolyyne to [6,6]-phenyl C₆₁-butyric acid methyl ester and the best-performing polymer showed a power conversion efficiency (PCE) up to ∼1.3% with a corresponding peak external quantum efficiency of 63% under air mass (AM1.5) simulated solar illumination even at shorter absorption wavelength regime. The power dependencies of the solar cell parameters (including the short-circuit current density, open-circuit voltage, fill-factor and PCE) were also tested in detail.