Synthesis of silyl-functionalized oligothiophene-based polymers with bright blue light-emission and high refractive index

Fluorescence Enhancement of Pyrene Chromophores Induced by Alkyl Groups through σ–π Conjugation: Systematic Synthesis of Primary, Secondary, and Tertiary Alkylated Pyrenes at the 1, 3, 6, and 8 Positions and Their Photophysical Properties

“…The PL properties of dyes that show σ*−π* conjugation between various Si–C σ-orbitals and chromophores has been investigated previously. It has been reported that Si–C substituents such as trimethylsilyl and trimethylsilylmethyl can improve the fluorescence quantum yields of the chromophores. ,− ,, However, in our results, the enhancement of Φ F upon the introduction of a TMS group was not much different from that caused by the introduction of an alkyl group. Moreover, since the Φ F of tetrakis(trimethylsilyl)pyrene is 0.57 in cyclohexane, it can be said that the tetraalkylated P4b also fluoresces strongly.…”

“…For these applications, the most general and important strategy for designing fluorescent materials based on the pyrene chromophore is to introduce substituents at the 1-, 3-, 6-, and 8-positions in the pyrene. For instance, it is widely known that the introduction of phenyl − and ethynyl groups − or trimethylsilyl (TMS) ,− and trimethylsilylmethyl (TMSM) groups at the 1-, 3-, 6-, and 8-positions in pyrene expand the π-system and increase the oscillator strength, resulting in dramatic improvements in the photoluminescence (PL) properties, especially in the fluorescence quantum yield. In addition, various functional groups such as carbonyl groups have been also used to modify the PL properties as well as the mechanisms of the PL in pyrene. − Furthermore, these pyrene dyes have often been introduced into sophisticated structures such as spiro skeletons, polymers, − cyclophanes, , calix arenes, , and inorganic matrixes , to obtain various desired functions.…”

Perfectly Regioregular Electroactive Polyolefins: Impact of Inter-Chromophore Distance on PLED EQE

“…To determine the effects of chromophore separation on device parameters, we have prepared a set of perfectly regioregular electroactive polyolefins with carefully controlled average chromophore–chromophore distances. As shown in Figure A, regioregular electroactive polyolefins comprise a class of materials in which the active pendant group occurs at exactly defined backbone run length intervals (spacer lengths). , These regioregular materials are analogous to previously reported vinyl type or regiorandom polymers containing pendant electroactive moieties (Figure B). − Similar to main chain π-functional materials (Figure C), − pendant π-functional polymers offer the opportunity for inclusion of various electroactive units, which may serve their purposes cooperatively (e.g., various chromophores for white emission, emissive units and charge transporters, etc. ) ,, and thus afford an interesting and relatively new avenue for exploration into optoelectronic materials, as compared to conjugated polymers (Figure D).…”

Synthesis of PVA/CeO2 Based Nanocomposites with Tuned Refractive Index and Reduced Absorption Edge: Structural and Optical Studies

“…It is shown that a broad dispersion region and a high refractive index over a wide spectrum of wavelengths characterize the samples. The high n polymers have recently been used for several applications, such as display devices, advanced organic light-emitting diodes (OLEDs), anti-refractive coatings, and various semiconductors [ 43 , 44 ]. Based on this impressive property, numerous researchers have focused on increasing the n of polymers.…”