Synthesis and photophysical properties of novel butterfly-shaped blue emitters based on pyrene

Synthesis and photophysical properties of novel butterfly-shaped blue emitters based on pyren

An efficient approach to the synthesis of novel pyrene-fused azaacenes

An efficient approach to the synthesis of novel pyrene-fused azaacene

Synthesis and fluorescence emission properties of 1,3,6,8-tetraarylpyrenes

Synthesis and fluorescence emission properties of 1,3,6,8-tetraarylpyrene

Pyrene-cored blue-light emitting [4]helicenes: synthesis, crystal structures, and photophysical properties

The synthesis, crystal structures and photophysical properties of two types of pyrene-cored blue-light emitting [4]helicenes are reported, in which two naphthalene rings of condensed pyrenes were constructed resulting in helical architectures. The photophysical properties and electrochemical characteristics of these pyrene-cored [4]helicenes were fully investigated in both solutions and films, along with that of the pre-cyclization Q4 products, 4,9- and 4,10-(phenylethenyl)pyrenes

Naphthodithiophenediimide (NDTI): Synthesis, Structure, and Applications

A straightforward synthesis of α,β-unsubstituted and α-halogenated naphtho­[2,3-<i>b</i>:6,7-<i>b</i>′]­dithiophenediimides (NDTIs) is described. Electrochemical and optical studies of <i>N</i>,<i>N</i>-dioctyl-NDTI demonstrate that the compound has a low-lying LUMO energy level (4.0 eV below the vacuum level) and a small HOMO–LUMO gap (∼2.1 eV). With its interesting electronic and optical properties, in addition to its planar structure, NDTI is a promising building block for the development of novel π-functional materials. In fact, it afforded n-channel, p-channel, and ambipolar materials, depending on the molecular modification

Naphthodithiophenediimide (NDTI): Synthesis, Structure, and Applications

A straightforward synthesis of α,β-unsubstituted and α-halogenated naphtho­[2,3-<i>b</i>:6,7-<i>b</i>′]­dithiophenediimides (NDTIs) is described. Electrochemical and optical studies of <i>N</i>,<i>N</i>-dioctyl-NDTI demonstrate that the compound has a low-lying LUMO energy level (4.0 eV below the vacuum level) and a small HOMO–LUMO gap (∼2.1 eV). With its interesting electronic and optical properties, in addition to its planar structure, NDTI is a promising building block for the development of novel π-functional materials. In fact, it afforded n-channel, p-channel, and ambipolar materials, depending on the molecular modification

Blue-emitting butterfly-shaped 1,3,5,9-tetraarylpyrenes: synthesis, crystal structures, and photophysical properties

Blue-emitting butterfly-shaped 1,3,5,9-tetraarylpyrenes: synthesis, crystal structures, and photophysical propertie

Blue-Emitting Butterfly-Shaped 1,3,5,9-Tetraarylpyrenes: Synthesis, Crystal Structures, and Photophysical Properties

The first example of aryl-functionalized, butterfly-shaped, highly fluorescent and stable blue-emitting monomers, namely, 7-<i>tert</i>-butyl-1,3,5,9-tetrakis(<i>p</i>-R-phenyl)pyrenes, were synthesized by the Suzuki–Miyaura cross-coupling reaction from a novel bromide precursor of 1,3,5,9-tetrabromo-7-<i>tert</i>-butylpyrene. The crystal structures and optical and electronic properties have been investigated

Synthesis and Optical Properties of Donor–Acceptor-Type 1,3,5,9-Tetraarylpyrenes: Controlling Intramolecular Charge-Transfer Pathways by the Change of π‑Conjugation Directions for Emission Color Modulations

In dipolar organic π-conjugated molecules, variable photophysical properties can be realized through efficient excited-state intramolecular charge transfer (ICT), which essentially depends on the π-conjugation patterns. Herein, we report a controllable regioselective strategy for synthesis and optical properties of two donor–acceptor (DA)-type 1,3,5,9-tetraarylpyrenes (i.e., 1,3-A/5,9-D (<b>4b</b>) and 1,3-D/5,9-A (<b>4c</b>)) by covalently integrating two phenyl rings and two <i>p</i>-OMe/CHO-substituted phenyl units into the 2-<i>tert</i>-butylpyrene building block, in which the two phenyl rings substituted at the 1,3-positions act as acceptors for <b>4b</b> or as donors for <b>4c</b> and the two <i>p</i>-OMe or <i>p</i>-CHO-substituted phenyl moieties substituted at the K-region of 5,9-positions act as donors for <b>4b</b> or as acceptors for <b>4c</b>, respectively. Density functional theory calculations on their frontier molecular orbitals and UV–vis absorption of S₀ → S₁ transition theoretically predicted that the change of π-conjugation directions in the two DA pyrenes could be realized through a variety of substitution patterns, implying that the dissimilar ground-state and excited-state electronic structures exist in each molecule. Their single-crystal X-ray analysis reveal their highly twisted conformations that are beneficial for inhibiting the π-aggregations, which are strikingly different from the normal 1,3,5,9-tetraphenylpyrenes (<b>4a</b>) and related 1,3,6,8-tetraarylpyrenes. Indeed, experimental investigations on their optical properties demonstrated that the excited-state ICT pathways can be successfully controlled by the change of π-conjugation directions through the variety of substitution positions, resulting in the modulations of emission color from deep-blue to green in solution. Moreover, for the present DA pyrenes, highly fluorescent emissions with moderate-to-high quantum yields both in the thin film and in the doped poly­(methyl methacrylate) film were obtained, suggesting them as promising emitting materials for the fabrication of organic light-emitting diodes

Synthesis and Optical Properties of Donor–Acceptor-Type 1,3,5,9-Tetraarylpyrenes: Controlling Intramolecular Charge-Transfer Pathways by the Change of π‑Conjugation Directions for Emission Color Modulations

In dipolar organic π-conjugated molecules, variable photophysical properties can be realized through efficient excited-state intramolecular charge transfer (ICT), which essentially depends on the π-conjugation patterns. Herein, we report a controllable regioselective strategy for synthesis and optical properties of two donor–acceptor (DA)-type 1,3,5,9-tetraarylpyrenes (i.e., 1,3-A/5,9-D (<b>4b</b>) and 1,3-D/5,9-A (<b>4c</b>)) by covalently integrating two phenyl rings and two <i>p</i>-OMe/CHO-substituted phenyl units into the 2-<i>tert</i>-butylpyrene building block, in which the two phenyl rings substituted at the 1,3-positions act as acceptors for <b>4b</b> or as donors for <b>4c</b> and the two <i>p</i>-OMe or <i>p</i>-CHO-substituted phenyl moieties substituted at the K-region of 5,9-positions act as donors for <b>4b</b> or as acceptors for <b>4c</b>, respectively. Density functional theory calculations on their frontier molecular orbitals and UV–vis absorption of S₀ → S₁ transition theoretically predicted that the change of π-conjugation directions in the two DA pyrenes could be realized through a variety of substitution patterns, implying that the dissimilar ground-state and excited-state electronic structures exist in each molecule. Their single-crystal X-ray analysis reveal their highly twisted conformations that are beneficial for inhibiting the π-aggregations, which are strikingly different from the normal 1,3,5,9-tetraphenylpyrenes (<b>4a</b>) and related 1,3,6,8-tetraarylpyrenes. Indeed, experimental investigations on their optical properties demonstrated that the excited-state ICT pathways can be successfully controlled by the change of π-conjugation directions through the variety of substitution positions, resulting in the modulations of emission color from deep-blue to green in solution. Moreover, for the present DA pyrenes, highly fluorescent emissions with moderate-to-high quantum yields both in the thin film and in the doped poly­(methyl methacrylate) film were obtained, suggesting them as promising emitting materials for the fabrication of organic light-emitting diodes