‘Cloverleaf’ crown ether resorcin[4]arenes

Crown ether resorcin[4]arenes 1a, 1b, and 2b with a novel connectivity have been prepared from diquinoxaline cavitands in yields of 68%, 73%, and 25%, respectively. The reaction involves bridging the contiguous oxygen atom pairs with tri-, tetra- or pentaethylene glycol ditosylates.     

Investigation into the surface modification of aragonite whiskers

Aragonite whiskers (AWs) were treated with several fatty acid surfactants and silane coupling agent in order to determine the optimal modifier by using contact angle measurements. The results revealed that the AWs modified by fatty acids showed more remarkable increase in the contact angle than by silane, suggesting the former were preferentially applied in modifying AWs. While the samples coated with fatty acids exhibited hydrophobicity with contact angles ranging from 104.08° to 137.87° with increasing of carbon chain length. Therefore, the highest contact angle of AWs treated by oleic acid was discussed in detail as an example, which was characterized by field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), thermo‐gravimetry analyses (TGA), X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). FESEM and TEM results showed a thin layer coated on the modified sample surface. Both the results of TGA and XPS confirmed organic groups existed in the sample of AWs treated by oleic acid. FTIR demonstrated that calcium dioleate was formed in the modification process. Further, modification mechanism was proposed based on the obtained results. Copyright © 2016 John Wiley & Sons, Ltd.     

Amine-Responsive Disassembly of AuI–CuI Double Salts for Oxidative Carbonylation

A sensitive amine-responsive disassembly of self-assembled Au^I-Cu^I double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)₂][CuI₂] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)₂]⁺ and the capacity of [CuI₂]⁻ on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d¹⁰ metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.     

Cy5.5-MSA-G250 nanoparticles (CMGNPs) induce M1 polarity of RAW264. 7 macrophage cells via TLR4-dependent manner

CMGNPs can promote M1 polarization of macrophages and TLR4 is involved in CMGNP-induced inflammation.     

Recent advances in carbon nanostructures prepared from carbon dioxide for high-performance supercapacitors

The burgeoning global economy during the past decades gives rise to the continuous increase in fossil fuels consumption and rapid growth of CO₂ emission,which demands an urgent exploration into green and sustainable devices for energy storage and power management.Supercapacitors based on activated carbon electrodes are promising systems for highly efficient energy harvesting and power supply,but their promotion is hindered by the moderate energy density compared with batteries.Therefore,scalable conversion of CO₂ into novel carbon nanostructures offers a powerful alternative to tackle both issues:mitigating the greenhouse effect caused by redundant atmospheric CO₂ and providing carbon materials with enhanced electrochemical performances.In this tutorial review,the techniques,opportunities and barriers in the design and fabrication of advanced carbon materials using CO₂ as feedstock as well as their impact on the energy-storage performances of supercapacitors are critically examined.In particular,the chemical aspects of various Cv2 conversion reactions are highlighted to establish a detailed understanding for the science and technology involved in the microstructural evolution,surface engineering and porosity control of CO₂-converted carbon nanostructures.Finally,the prospects and challenges associated with the industrialization of CO₂ conversion and their practical application in supercapacitors are also discussed.     

Palladium Catalysis for Aerobic Oxidation Systems Using Robust Metal–Organic Framework

Described here is a new and viable approach to achieve Pd catalysis for aerobic oxidation systems (AOSs) by circumventing problems associated with both the oxidation and the catalysis through an all‐in‐one strategy, employing a robust metal–organic framework (MOF). The rational assembly of a Pd^II catalyst, phenanthroline ligand, and Cu^II species (electron‐transfer mediator) into a MOF facilitates the fast regeneration of the Pd^II active species, through an enhanced electron transfer from in situ generated Pd⁰ to Cu^II, and then Cu^I to O₂, trapped in the framework, thus leading to a 10 times higher turnover number than that of the homogeneous counterpart for Pd‐catalyzed desulfitative oxidative coupling reactions. Moreover, the MOF catalyst can be reused five times without losing activity. This work provides the first exploration of using a MOF as a promising platform for the development of Pd catalysis for AOSs with high efficiency, low catalyst loading, and reusability.     

Influence of lanthanum on morphology and electrochemical performance of nano-platinum-based catalytic membrane electrode

The current research of platinum (Pt)–based catalysts focuses on reducing Pt loading in the catalysts while enhancing the catalytic activity. As a rare-earth element, lanthanum (La) has demonstrated good synergistic effect with Pt-based catalysts, because of its catalytic promoting capability and high dispersibility. Here, we fabricated La-doped nano-Pt-based catalytic membrane electrode using ion beam sputtering method. The effect of La on the morphology and electrochemical performance of the catalytic membrane electrode was investigated by scanning electron microscope, X-ray photoelectron spectroscopy, and electrochemical measurements. Compared with pure Pt-based sample, the electrochemical activity specific area of the La-doped sample increases by 74.59%, with 63.95% increase in exchange current density. The results also show that La₂O₃ enhances oxygen enrichment of the membrane electrode and reduces interfacial energy among Pt grains while pinning the grain boundaries. In addition, the inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurement shows that the Pt loading in the membrane electrodes is below 0.1 mg/cm². Thus, enhanced catalytic performance is achieved in catalysts with lower Pt loading.     

气相色谱-质谱法同时测定氧化型染发剂中的多种染料中间体

氧化型染发剂是广泛使用的永久性染发剂.因其多具致敏性或致癌性,因此我国《化妆品卫生规范》对其作了限量使用规定,并采用高效液相色谱法（HPLC）测定其中8种染料中间体,但在实际应用中由于样品基体复杂,导致分离效果不理想、定性困难等问题.《欧盟化妆品规程》采用的薄层色谱法能很好地分离和鉴别各种染料组分,但对其进行精确定量存在一定困难.我国行业标准推荐的气相色谱法只能测定其中对苯二胺一种组分,故使用价值不高.本采用气相色谱-质谱法（GC/MS）同时测定染发剂中的（1）邻苯二胺、（2）对苯二胺、（3）对氨基酚、（4）间氨基酚、（5）对苯二酚、（6）间苯二酚、（7）2,5-二氨基甲苯硫酸盐及（8）4-甲胺苯酚硫酸盐等8种氧化型染料中间体,可满足化妆品监督管理的需求.     

调控供电子策略简易制备近红外二区有机小分子光学诊疗试剂

有机小分子凭借着明确的化学结构、出色的生物相容性、优异的可重复性等诸多优势被广泛应用于光学诊疗领域. 然而, 目前报道的有机小分子存在合成步骤复杂、成像波长位于近红外一区(NIR-I)、光热转换效率及单线态氧产率低等缺陷, 严重限制了其诊疗效果. 基于此, 本工作以吡咯并吡咯二酮作为缺电子单元、分别以苯、苯胺、邻苯二胺作为供电子单元, 通过一步偶联反应简易制备得到三种有机小分子DPP-0、DPP-2、DPP-4, 进一步利用纳米沉淀法制备得到对应的水溶性纳米粒子DPP-0 NPs、DPP-2 NPs和DPP-4 NPs. 研究发现, 随着氨基数量的增加, 纳米粒子吸收/发射均发生了红移, 其中DPP-4 NPs具有良好的NIR-I吸收能力且其最大荧光发射达到了近红外二区(NIR-II)区域, 表明可以通过改变供电子单元策略实现光学性能的调控. 在单一激光照射下, DPP-4 NPs可以同时产生NIR-II荧光信号、过高热及单线态氧, 其光热转换效率和单线态氧产率分别高达40.2%及34.3%, 可成功应用于肿瘤深层次NIR-II荧光成像诊断及高效光热/光动力联合治疗.     

压强对钙钛矿薄膜形貌和结晶性影响的研究

采用新型简便的方法控制钙钛矿层薄膜的结晶过程,对优化制备工艺、获得高性能器件至关重要。本文采用调节真空度的方法有效控制钙钛矿层结晶,系统地研究了压强的作用及其对晶体生长、薄膜形成及器件性能的影响。采用扫描电子显微镜(SEM)、紫外-可见吸收光谱、X射线衍射光谱(XRD)谱图等手段对钙钛矿层的形貌及结晶程度进行了分析表征。在此基础上,制备出器件结构为Glass/ITO/PEDOT:PSS/CH3NH3PbI3/PCBM/Al的钙钛矿太阳能电池,考察了不同压强下的器件性能。结果表明:随压强降低,钙钛矿层结晶程度明显提高,孔洞减少,表面覆盖率提高。同时,器件的短路电流、填充因子以及光电转化效率均随压强降低而提高,器件效率由原来的10.38%提高到12.36%,提高了19%。