摘要：
In this paper, we synthesized and characterized a di-tetradentate macrocyclic ligand as a novel resonance fluorescence probe for the determination of uranium. The ligand contains two tetradentate ligand moieties and can chelate two cations to form binuclear complex. We found that when the ligand only chelates a uranyl ion or europium (III) ion, the formed complex can only produce weak resonance fluorescence. When the ligand chelates simultaneously uranyl and europium (III) to form heterobinuclear complex, the formed complex can produce strong resonance fluorescence due to the cation-cation interaction between uranyl and europium (III). Based on this finding, we established a resonance fluorescence chemosensor for the determination of uranium (VI) by utilizing the formation of the heterobinuclear complex. Under optimal conditions, the linear range for the determination of uranium (VI) is 0.008-1.2 nmol mL(-1) with a detection limit of 0.002 nmol mL(-1). The method has been applied to determine uranium (VI) in environmental water samples with the recoveries between 95.7% and 103.6%. (C) 2018 Elsevier B.V. All rights reserved.
通讯机构：
[Wang, Hongqing] U;Univ South China, Coll Chem & Chem Engn, 28 Changsheng West Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
Aluminum ions;Cell imaging;Fluorescence probe;Schiff's base
摘要：
<![CDATA[<ce:abstract xmlns:ce="" xmlns="" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0080" view="all">A reversible Schiff's base fluorescence probe for Al<ce:sup loc="post">3+</ce:sup>, (3,5-dichloro-2- hydroxybenzylidene) quinoline-2-carbohydrazide (<ce:bold>QC</ce:bold>), based on quinoline derivative has been designed, synthesized and evaluated. The<ce:bold>QC</ce:bold>exhibited a high sensitivity and selectivity toward Al<ce:sup loc="post">3+</ce:sup>in EtOH-H<ce:inf loc="post">2</ce:inf>O (v/v=1:9, pH=6) by forming a 1:1 complex with Al<ce:sup loc="post">3+</ce:sup>and the detection limit of<ce:bold>QC</ce:bold>for Al<ce:sup loc="post">3+</ce:sup>was as low as 0.012μM. Furthermore, these results displayed that the binding of<ce:bold>QC</ce:bold>Al<ce:sup loc="post">3+</ce:sup>was broken by F<ce:sup loc="post">?</ce:sup>, so this system could be used to monitor F<ce:sup loc="post">?</ce:sup>in the future. The enhancement fluorescence of the<ce:bold>QC</ce:bold>could be attributed to the inhibition of PET and ESIPT and the emergency of CHEF process induced by Al<ce:sup loc="post">3+</ce:sup>. More importantly,<ce:bold>QC</ce:bold>was not only successfully used for the determination of trace Al<ce:sup loc="post">3+</ce:sup>in the tap water and the human blood serum, but was valid for fluorescence imaging of Al<ce:sup loc="post">3+</ce:sup>in the Hela cells.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="" xmlns="" id="ab0010" class="graphical" xml:lang="en" view="all"><ce:section-title id="st0010">Graphical Abstract</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para>Display Omitted</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:c
通讯机构：
[Lin, Ying-Wu] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;Univ South China, Lab Prot Struct & Funct, Hengyang 421001, Peoples R China.
摘要：
Neuroglobin (Ngb), with its physiological role not fully understood, was found to be capable of self-oxidation of methionine64 introduced at the heme axial position (H64M Ngb), adopting a high-spin heme state and producing both methionine sulfoxide (SO-Met) and sulfone (SO2-Met), which represents the structure and function of cytochrome c in a non-native state.
作者机构：
[Lu, Yunfeng; Shen, Li; Wang, Xiaofeng; Liu, Fang; Wu, Hao Bin] Univ Calif Los Angeles, Dept Chem & Biomol Engn, Los Angeles, CA 90095 USA.;[Wu, Hao Bin] Zhejiang Univ, Sch Mat Sci & Engn, Hangzhou 310027, Peoples R China.;[Zink, Jeffrey I.; Brosmer, Jonathan L.] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA.;[Wang, Xiaofeng] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Cai, Mei; Xiao, Qiangfeng] Gen Motors Res & Dev Ctr, 30500 Mound Rd, Warren, MI 48090 USA.
通讯机构：
[Lu, Yunfeng; Wang, Ge; Dunn, Bruce] U;Univ Calif Los Angeles, Dept Chem & Biomol Engn, Los Angeles, CA 90095 USA.;Univ Sci & Technol Beijing, Sch Mat Sci & Engn, Beijing 100083, Peoples R China.;Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA.
关键词：
biomimetic ionic channels;lithium-ion electrolyte;lithium-metal batteries;metal–organic frameworks;open metal sites
摘要：
The wettability, or hydrophobic-hydrophilic balance, of cathode catalyst layer influences the performance of the proton exchange membrane fuel cell. In this paper, cathode catalyst layer with different polytetrafluoroethylene contents are prepared, and the effect of hydrophobic-hydrophilic balance on the performance of the membrane electrode assembly is investigated intensively. It is found that wettability, or hydrophobic-hydrophilic balance, of cathode catalyst layer can significantly affect the performance of membrane electrode assembly, and it can be effectively tuned by varying the loading of polytetrafluoroethylene. With the addition of polytetrafluoroethylene, the hydrophobicity of cathode catalyst layer, reflected by the contact angel, can be changed from 135.6 degrees of that without addition of polytetrafluoroethylene to 146.5 degrees with 70 wt.% polytetrafluoroethylene addition, and the optimal addition amount is 50 wt.%. For our optimal membrane electrode assembly with optimal addition of polytetrafluoroethylene in cathode, its current density are recorded as 990 mAcm(-2) at 0.7 V and 1400mA cm(-2) at 0.6 V, respectively; its maximum power density is up to 856mWcm(-2). Furthermore, our polytetrafluoroethylene-incorporated membrane electrode assembly also exhibits excellent stability, and current density only drops from 1000mA cm(-2) to 900mA cm(-2) after a continuous operation of 60 h. (C) 2018 Elsevier Ltd. All rights reserved.
作者机构：
[Zhao, Yu-Bao; Zhang, Xiao-Lin] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Mei, Lei; Zhang, Xiao-Lin; Hu, Kong-Qiu; Chai, Zhi-Fang; Shi, Wei-Qun] Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.;[Wang, Yi-Tong] China Int Engn Consulting Corp, Beijing 100089, Peoples R China.
通讯机构：
[Zhao, Yu-Bao] U;[Shi, Wei-Qun] C;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.
摘要：
<![CDATA[We report five novel uranyl coordination polymers, [(CH_(3))_(2)NH_(2)]UO_(2)(BTPCA) (<b>1 ), [(CH_(3))_(2)NH_(2)]UO_(2)(BTPCA) (<b>2 ), [(CH_(3))_(2)NH_(2)]_(2)[UO_(2)(BTPCA)][UO_(2)(BTPCA)]·(H_(2)O)_(5.5) (<b>3 ), [(CH_(3))_(2)NH_(2)]_(2)(UO_(2))_(2)(BTPCA)_(2)·(H_(2)O)_(3) (<b>4 ), and [(CH_(3))_(2)NH_(2)]UO_(2)(BTPCA) (<b>5 ), by the utilization of semirigid ligand 1,1′,1″-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid (H_(3)BTPCA) and uranyl nitrate through solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that the five compounds share a similar structure composition and local coordination mode to the exclusion of disordered water or DMF molecules. Each UO_(2)(COO)_(3)~(–) motif is connected to six neighboring units through three BTPCA~(3–) ligands, generating an infinite uranyl honeycomb (6, 3) net. The structures of all the five compounds consist of 2D honeycomb nets of various degrees of distortions, which are induced by the flexibility of piperidine rings. The dimethylamine cations and solvent molecules fill in the space between layers. Therefore, these five compounds are isomers in a broad sense. Notably, both compounds <b>3 and <b>4 possess 2-fold interpenetrated structures. For compound <b>5 , the distance between the neighboring 2D honeycomb nets is 7.253 ?. This is the largest distance between the 2D honeycomb nets in uranyl-based coordination polymers, to the best of our knowledge. In addition, compounds <b>1 , <b>2 , and <b>4 are also characterized by infrared spectroscopy (IR), thermogravimetric analysis (TG), powder X-ray diffraction (PXRD), and luminescence properties.]]>
摘要：
The design of functional metallohydrogels is attractive but challenging. A rational approach is introduced for designing functional metallohydrogels using chiral ligands, a phenylalanine derivative with a pyridyl group (l/d-PF). Intriguingly, the as-prepared metallohydrogel exhibits excellent O2 binding and activating properties. Insights into the O2 binding pathway reveals the presence of a novel [(l+d)-PF-Cu3+-O2−] species, which can efficiently reduce ferric cytochrome c with the reactive O2− by receiving an electron from reductant ascorbic acid. This study provides helpful instructions for developing new artificial systems with specific functions through the effective combination of chiral ligands with metal ions.
期刊：
Chemical Communications,2018年54(34):4356-4359 ISSN：1359-7345
通讯作者：
Lin, Ying-Wu
作者机构：
[Yin, Lu-Lu; Lin, Ying-Wu; Du, Ke-Jie; He, Bo] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Yuan, Hong; Tan, Xiangshi] Fudan Univ, Dept Chem, Shanghai 200433, Peoples R China.;[Yuan, Hong; Tan, Xiangshi] Fudan Univ, Inst Biomed Sci, Shanghai 200433, Peoples R China.;[Gao, Shu-Qin; Wen, Ge-Bo; Lin, Ying-Wu] Univ South China, Lab Prot Struct & Funct, Hengyang 421001, Peoples R China.
通讯机构：
[Lin, Ying-Wu] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;Univ South China, Lab Prot Struct & Funct, Hengyang 421001, Peoples R China.
摘要：
A de novo designed intramolecular disulfide bond in myoglobin, resembling that in cytoglobin without structural evidence, was confirmed by an X-ray structure for the first time and was demonstrated to regulate both the structure and function of this protein, which fulfills the design of an artificial dehaloperoxidase, with an activity exceeding that of a native enzyme.
