Switching on elusive organometallic mechanisms with photoredox catalysis
作者:Jack A. Terrett、James D. Cuthbertson、Valerie W. Shurtleff、David W. C. MacMillan
DOI:10.1038/nature14875
日期:2015.8
step) to occur via a Ni(iii) alkoxide intermediate. Here we demonstrate that visible-light-excited photoredox catalysts can modulate the preferred oxidation states of nickel alkoxides in an operative catalytic cycle, thereby providing transient access to Ni(iii) species that readily participate in reductive elimination. Using this synergistic merger of photoredox and nickel catalysis, we have developed
Synthesis and Mesomorphic Properties of Two Series of Laterally Fluorinated Symmetric Ester Liquid Crystals
作者:Qiang Wei、Xiaotao Yuan、Lipei Zhang、Liping Wang、Huai Yang、Yangbin Wang
DOI:10.1080/15421400802198359
日期:2008.7.30
Two series of symmetric ester liquid crystals (nAFBHQ and nADFBHQ) with lateral fluorine atoms have been synthesized. Their chemical structures were measured by FTIR, H-1 NMR, and elemental analysis (EA). Their mesomorphic properties were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that both series showed nematic phase only. And their melting point and clearing point decreased with the number of carbon atoms in alkoxy group. It can also be found that nAFBHQ have approximately the same temperatures of melting point but much higher temperatures of clearing point than their corresponding compound in nADFBHQ series.
Controlling Mirror Symmetry Breaking and Network Formation in Liquid Crystalline Cubic, Isotropic Liquid and Crystalline Phases of Benzil‐Based Polycatenars
作者:Tino Reppe、Silvio Poppe、Carsten Tschierske
DOI:10.1002/chem.202002869
日期:2020.12.4
capable of forming a wide variety of helically twisted networkstructures in the liquid, the liquidcrystalline (LC) and the crystalline state. Single polar substituents at the apex of tricatenar molecules support the formation of the achiral (racemic) cubic double networkphase with Ia d symmetry and relatively small twist along the networks. The combination of an alkyl chain with fluorine substitution
Metallaphotoredox C−O and C−N Cross‐Coupling Using Donor‐Acceptor Cyanoarene Photocatalysts
作者:Tommaso Gandini、Luigi Dolcini、Lorenzo Di Leo、Matthieu Fornara、Alberto Bossi、Marta Penconi、Alberto Dal Corso、Cesare Gennari、Luca Pignataro
DOI:10.1002/cctc.202200990
日期:2022.12.7
Timely delay: Donor-acceptor cyanoarenes capable of thermally activated delayed florescence (TADF) are shown to effectively promote metallaphotoredoxC−O and C−Ncoupling in the presence of light and a nickel catalyst. These readily available organic dyes represent a convenient replacement for precious metal photocatalysts.