Letter Ruling 99-1: Electronic Retailers

The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]­Cl_{(1–<i>p</i>)}{CCC₆H_5–<i>m</i>(CCFlu)_<i>m</i>}_(1+<i>p</i>)]­[PF₆]_<i>n</i> are reported (<i>n</i> = 0–1; <i>m</i> = 1–2; [M] = [Fe­(η⁵-C₅Me₅)­(κ²-dppe)] and <i>p</i> = 1 or [M] = [<i>trans</i>-Ru­(κ²-dppe)₂] and <i>p</i> = 0–1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru­(II) compounds in the 600–800 nm range (<i>Z</i>-scan) make them attractive nonlinear chromophores. Structure–property studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range

Spirobifluorenyl-porphyrins and their derived polymers for homogeneous or heterogeneous catalysis

International audienceDecorating porphyrin cores at their meso positions by one, two or four 9,9'-Spirobifluorenyl (SBF) units is an interesting design strategy to obtain efficient and recyclable heterogeneous catalysts for various chemical reactions. The synthesis of metalloporphyrin polymers (RuIICO, FeIIICl, MnIIICl) is easily performed along anodic oxidation of their related monomers or along copolymerization of their monomers in presence of 9,9'-SBF. The efficiency of this polymerization mainly depends on the number of SBF units around the porphyrin cores and on the nature of the metal ion within the porphyrin ligand. Polymer catalysts in heterogeneous phase appear as efficient as the monomer catalysts in homogeneous phase. The main interest of catalysis with polymers is that they can be very easily separated from the reaction medium after reaction by a simple filtration and that they can be washed and reused without loss of their activity. The recyclability of metalloporphyrins polymers is of high interest in the field of catalysis. For asymmetric catalysis, recyclable chiral polymetalloporphyrins based on the SBF scaffold are also of high interest. The chirality may be introduced either by the dimethanoanthracenyl (DMA) units linked to SBF units (acting as electropolymerizable entities) or by a chiral SBF fragment which can be electropolymerizable. Compared to other porphyrin immobilization processes, anodic oxidation is hence a relatively easy tool as the polymer is directly obtained on the anode surface, easily separated under its insoluble form and directly usable as recyclable catalyst for many chemical reactions. © Springer International Publishing Switzerland 2016

New polyfluorenylidenes substituted by donnor or acceptor groups

L'oxydation anodique des fluorénylidènes I, II et III conduit dans des conditions expérimentales définies à des polymères dont l'état d'oxy dation varie avec le potentiel auquel ils sont polarisés. La présence de groupement(s) cyano dans les poly(II) et (III) permet la préparation de composites polymère-métal (Au, Ag, Pt, Pd). Ces composites ont été utilisés comme matériau d'électrode lors de l'oxydation de différents substrats (hydrazine, méthanol, formaldehyde, azoture ...)

Blue Single-Layer Organic Light-Emitting Diodes Using Fluorescent Materials: A Molecular Design View Point

International audienceSince the beginning of organic light-emitting diodes (OLEDs), blue emission has attracted the most attention and many research groups worldwide have worked on the design of materials for stable and highly efficient blue OLEDs. However, almost all the high-efficiency blue OLEDs using fluorescent materials are multilayer devices, which are constituted of a stack of organic layers to improve the injection, transport, and recombination of charges within the emissive layer. Although the technology has been mastered, it suffers from real complexity and high cost and is time-consuming. Simplifying the multilayer structure with a single-layer one, the simplest devices made only of electrodes and the emissive layer have appeared as an appealing strategy for this technology. However, removing the functional organic layers of an OLED stack leads to a dramatic decrease of the performance and achieving high-efficiency blue single-layer OLEDs requires intense research especially in terms of materials design. Herein, an exhaustive review of blue emitting fluorophores that have been incorporated in single-layer OLEDs is reported, and the links between their electronic properties and the device performance are discussed. Thus, a structure/properties/device performance relationship map is drawn, which is of interest for the future design of organic materials

Anodic oxidation of indenofluorene. Electrodeposition of electroactive poly(indenofluorene)

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Encumbered DiSpiro[Fluorene-IndenoFluorene]: Mechanistic Insights

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