Sterically Hindered Fluorenyl-Substituted Poly(p-phenylenevinylenes) for Light-Emitting Diodes
摘要:
A new series of processable dihexylfluorenyl-substituted poly(p-phenylenevinylene) derivatives (DHF-PPVs) were synthesized by dehydrohalogenation-condensation polymerization (GILCH polymerization). The polymers were characterized by NMR, FT-IR, and elemental analysis and were completely soluble in common organic solvents, All of the polymers demonstrated bright blue-green emission with high photoluminescence (PL) efficiencies of 68-71% in chloroform, good thermal stability with decomposition temperatures above 322degreesC, and high glass transition temperatures in the range of 113-148degreesC. Cyclic voltammetry studies revealed that these polymers undergo both irreversible oxidation and reduction onsets around 0.9 and -1.5 V, which are attributed to the conjugated backbone. Polymer light-emitting diodes (PLEDs), fabricated with DHF-PPVs, as the emitting layer, poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonic acid) (PSS) (PEDOT:PSS), as the hole injection/ transporting layer, Ca cathodes, and indium-tin oxide (ITO) anodes, (ITO/PEDOT:PSS/DHF-PPVs/Ca), emitted blue-green emission with a maximum peak around 500 nm and a shoulder peak around 532 nm. For the poly[2-(9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (DHF-PPV) device, a low turn-on voltage of 2.8 V (0.13 MV/cm), a maximum luminance of 12 000 cd/m(2) at 0.4 MV/cm, and a maximum external quantum efficiency of 0.53% were obtained, The latter was 33-37 times brighter and 1.6-2.8 times more efficient than those devices with poly[2-(7-methoxy-9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (MDHF-PPV) and poly[2-(7-cyano-9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (CNDHF-PPV).
Sterically Hindered Fluorenyl-Substituted Poly(p-phenylenevinylenes) for Light-Emitting Diodes
摘要:
A new series of processable dihexylfluorenyl-substituted poly(p-phenylenevinylene) derivatives (DHF-PPVs) were synthesized by dehydrohalogenation-condensation polymerization (GILCH polymerization). The polymers were characterized by NMR, FT-IR, and elemental analysis and were completely soluble in common organic solvents, All of the polymers demonstrated bright blue-green emission with high photoluminescence (PL) efficiencies of 68-71% in chloroform, good thermal stability with decomposition temperatures above 322degreesC, and high glass transition temperatures in the range of 113-148degreesC. Cyclic voltammetry studies revealed that these polymers undergo both irreversible oxidation and reduction onsets around 0.9 and -1.5 V, which are attributed to the conjugated backbone. Polymer light-emitting diodes (PLEDs), fabricated with DHF-PPVs, as the emitting layer, poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonic acid) (PSS) (PEDOT:PSS), as the hole injection/ transporting layer, Ca cathodes, and indium-tin oxide (ITO) anodes, (ITO/PEDOT:PSS/DHF-PPVs/Ca), emitted blue-green emission with a maximum peak around 500 nm and a shoulder peak around 532 nm. For the poly[2-(9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (DHF-PPV) device, a low turn-on voltage of 2.8 V (0.13 MV/cm), a maximum luminance of 12 000 cd/m(2) at 0.4 MV/cm, and a maximum external quantum efficiency of 0.53% were obtained, The latter was 33-37 times brighter and 1.6-2.8 times more efficient than those devices with poly[2-(7-methoxy-9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (MDHF-PPV) and poly[2-(7-cyano-9,9-dihexylfluorenyl)-1,4-phenylenevinylene] (CNDHF-PPV).
Structural diversity, luminescence and photocatalytic properties of six coordination polymers based on designed bifunctional 2-(imidazol-1-yl)terephthalic acid
A variety of amphiphobic porous materials are provided. The materials can include a variety of porous frameworks that have an outer surface functionalized by a plurality of perfluoroalkyl moieties. By careful selection of appropriate perfluoralkyl moieties, hydrophobic properties can be imparted to the exterior surface of the porous materials without significantly impacting the wetting properties of the porous interior. This can be used to create a variety of highly amphiphobic porous materials. Methods of making and using the amphiphobic porous materials are also provided.
Polymerizable biaryls, method for the production and use thereof
申请人:Aventis Research & Technologies GmbH & Co. KG
公开号:US06323373B1
公开(公告)日:2001-11-27
A process for preparing polymerizable biaryl derivatives comprises reacting an aromatic comprising a 6-membered ring which bears ester or benzylic OH groups in the 1,4 position with a second aromatic in a palladium-catalyzed cross-coupling reaction to give a biaryl and converting the ester or benzylic OH groups into polymerizable groups in one or more steps. The biaryls obtained are suitable for preparing polymers which are used as electroluminescence materials.