C–H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
作者:Bradley J. Gorsline、Long Wang、Peng Ren、Brad P. Carrow
DOI:10.1021/jacs.7b03887
日期:2017.7.19
catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C–H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C–H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples)
Enhanced Conjugated Polymer Fluorescence Quenching by Dipyridinium-Based Quenchers in the Presence of Surfactant
作者:Jyoti Dalvi-Malhotra、Liaohai Chen
DOI:10.1021/jp0455071
日期:2005.3.1
only 50% of fluorescence was recovered upon addition of DOTAP surfactant to the CHMB-quenched polymer solution. In contrast, no fluorescence was recovered when DTAB was added to either the MV- or CHMB-quenched polymer systems. Thus, fluorescence enhancement was observed for the polymer complex with DOTAP, whereas fluorescencequenching was predominant in the polymer complex with DTAB. Such studies will
Synthesis of Poly(arylenevinylene)s with Fluorinated Vinylene Units
作者:Francesco Babudri、Antonio Cardone、Gianluca M. Farinola、Carmela Martinelli、Raniero Mendichi、Francesco Naso、Marinella Striccoli
DOI:10.1002/ejoc.200700815
日期:2008.4
Poly(arylenevinylene) polymers bearing fluorine atoms in the vinyleneunits were obtained by a Stille cross-coupling reaction of (E)-(1,2-difluoro-1,2-ethenediyl)bis(tributylstannane) with diiodoaryl derivatives. The introduction of fluorine atoms on the double bond of the stannane leads to polymers with relatively high molecular weights. Furthermore, the presence of fluorinatedvinyleneunits changes
Highly selective binding of methyl orange dye by cationic water-soluble pillar[5]arenes
作者:L. S. Yakimova、D. N. Shurpik、L. H. Gilmanova、A. R. Makhmutova、A. Rakhimbekova、I. I. Stoikov
DOI:10.1039/c6ob00539j
日期:——
The bulky/negatively charged substituents of guest anions hinder the substrate entering the π-electron rich pillar[5]arene cavity.
客体阴离子的庞大/负电荷取代基阻碍了底物进入富含π电子的pillar[5]arene中空腔。
Fuel cell, polyelectrolyte and ion-exchange resin use for same
申请人:Morishima Makoto
公开号:US20050271923A1
公开(公告)日:2005-12-08
The object of this invention is to provide a solid polymer electrolyte which is excellent in durability and of low cost, and membranes, solutions for electrode catalyst coating, membrane/electrode assemblies and fuel cells which use the electrolyte. According to this invention, there can be provided a fuel cell which comprises an electrode assembly having an electrode catalyst membrane formed therein, said catalyst membrane comprising a polymer electrolyte membrane held between an anode on one side of the principal plane of the electrolyte membrane and a cathode on the other side of the principal lane thereof, current collecting plates provided each independently in close contact, to the anode side and the cathode side of the electrode assembly, and electroconductive separators having gas supply passages to the anode and to the cathode provided on the outside surfaces of the current collecting plates.