scholarly journals Aggregation-Enhanced Room-Temperature Phosphorescence from Au(I) Complexes Bearing Mesogenic Biphenylethynyl Ligands

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7255
Author(s):  
Andriani Furoida ◽  
Misato Daitani ◽  
Kyohei Hisano ◽  
Osamu Tsutsumi
Keyword(s):  
Liquid Crystalline ◽  
Room Temperature ◽  
Crystal Size ◽  
Molecular Geometry ◽  
Quantum Yields ◽  
Room Temperature Phosphorescence ◽  
Alkyl Chains ◽  
Aurophilic Interactions ◽  
Linear Coordination

Gold(I) complexes, enabling to form linear coordination geometry, are promising materials for manifesting both aggregation-induced emission (AIE) behavior due to strong intermolecular Au–Au (aurophilic) interactions and liquid crystalline (LC) nature depending on molecular geometry. In this study, we synthesized several gold(I) complexes with rod-like molecular skeletons where we employed a mesogenic biphenylethynyl ligand and an isocyanide ligand with flexible alkoxyl or alkyl chains. The AIE behavior and LC nature were investigated experimentally and computationally. All synthesized gold(I) complexes exhibited AIE properties and, in crystal, room-temperature phosphorescence (RTP) with a relatively high quantum yields of greater than 23% even in air. We have demonstrated that such strong RTP are drastically changed depending on the crystal-size and/or crystal growth process that changes quality of crystals as well as the aggregate structure, of e.g., Au–Au distance. Moreover, the complex with longer flexible chains showed LC nature where RTP can be observed. We expect these rod-like gold(I) complexes to have great potential in AIE-active LC phosphorescent applications such as linearly/circularly polarizing phosphorescence materials.

scholarly journals Regioisomeric Effect on the Excited-State Fate Leading to Room-Temperature Phosphorescence or Thermally Activated Delayed Fluorescence in a Dibenzophenazine-Cored Donor–Acceptor–Donor System

2021 ◽  
Author(s):  
Takumi Hosono ◽  
Nicolas Oliveira Decarli ◽  
Paola Zimmermann Crocomo ◽  
Tsuyoshi Goya ◽  
Leonardo Evaristo de Sousa ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Delayed Fluorescence ◽  
Quantum Yields ◽  
Room Temperature Phosphorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Emission Behavior

Exploring design principle for switching thermally activated dealyed fluorescecne (TADF) and room temperature phosphorescence (RTP) is a fundamentally imporant research in developing triplet-mediated photofunctional organic materials. Herein systematic studies on the regioisomeric and substituents effects in a twisted donor–acceptor–donor (D–A–D) scaffold (A = dibenzo[a,j]phenazine; D = dihydrophenazasiline) on the fate of the excited state have been performed. The study revealed that the regiosiomerism clearly affects the emission behavior of the D–A–D compounds. Distinct difference in TADF, dual TADF & RTP, and dual RTP were observed, depending on the host used. Furthermore, OLED organic light-emitting diodes (OLEDs) fabricated with the developed emitters achieved high external quantum yields for RTP-based OLEDS up to 7.4%.

Isophthalate-Based Room Temperature Phosphorescence: From Small Molecule to Side-Chain Jacketed Liquid Crystalline Polymer

2019 ◽  
Vol 52 (6) ◽  
pp. 2495-2503 ◽  
Author(s):  
Yan-Fang Zhang ◽  
Yue-Chao Wang ◽  
Xiao-Song Yu ◽  
Yang Zhao ◽  
Xiang-Kui Ren ◽  
...  
Keyword(s):  
Small Molecule ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Crystalline Polymer ◽  
Side Chain ◽  
Room Temperature Phosphorescence

Tunable lifetimes and efficiencies of room temperature phosphorescent liquids by modulating the length and number of alkyl chains

2020 ◽  
Vol 22 (35) ◽  
pp. 19746-19757
Author(s):  
Yuchen Zhang ◽  
Kai Zhang ◽  
Yuying Ma ◽  
Lili Lin ◽  
Chuan-Kui Wang ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Room Temperature ◽  
High Efficiency ◽  
Solvent Free ◽  
Large Area ◽  
Room Temperature Phosphorescence ◽  
Alkyl Chains ◽  
Liquid Systems

Organic room temperature phosphorescence (RTP) liquid composites exhibit the potential to make innovative changes in large area flexible lighting applications, and it is extremely challenging to achieve high-efficiency RTP in pure organic solvent-free liquid systems.

scholarly journals Liquid crystalline copper(i) complexes with bright room temperature phosphorescence

2020 ◽  
Vol 8 (19) ◽  
pp. 6552-6557 ◽  
Author(s):  
Raquel Giménez ◽  
Olga Crespo ◽  
Beatriz Diosdado ◽  
Anabel Elduque
Keyword(s):  
Liquid Crystal ◽  
Quantum Yield ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Crystal State ◽  
Yield Values

Phosphorescence in the liquid crystal state with one of the highest quantum yield values, 42%, at room temperature is reported.

scholarly journals Thermochemically Stable Liquid-Crystalline Gold(I) Complexes Showing Enhanced Room Temperature Phosphorescence

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 227 ◽  
Author(s):  
Yuki Kuroda ◽  
Shin-ya Nakamura ◽  
Katam Srinivas ◽  
Arruri Sathyanarayana ◽  
Ganesan Prabusankar ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Rational Design ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Decomposition Temperature ◽  
Ambient Conditions ◽  
Room Temperature Phosphorescence ◽  
Light Emitting ◽  
Phosphorescence Quantum Yield ◽  
Thermochemical Stability

Gold(I) complexes are some of the most attractive materials for generating aggregation-induced emission (AIE), enabling the realization of novel light-emitting applications such as chemo-sensors, bio-sensors, cell imaging, and organic light-emitting diodes (OLEDs). In this study, we propose a rational design of luminescent gold complexes to achieve both high thermochemical stability and intense room temperature phosphorescence, which are desirable features in practical luminescent applications. Here, a series of gold(I) complexes with ligands of N-heterocyclic carbene (NHC) derivatives and/or acetylide were synthesized. Detailed characterization revealed that the incorporation of NHC ligands could increase the molecular thermochemical stability, as the decomposition temperature was increased to ~300 °C. We demonstrate that incorporation of both NHC and acetylide ligands enables us to generate gold(I) complexes exhibiting both high thermochemical stability and high room-temperature phosphorescence quantum yield (>40%) under ambient conditions. Furthermore, we modified the length of alkoxy chains at ligands, and succeeded in synthesizing a liquid crystalline gold(I) complex while maintaining the relatively high thermochemical stability and quantum yield.

scholarly journals Engendering persistent organic room temperature phosphorescence by trace ingredient incorporation

2021 ◽  
Vol 7 (19) ◽  
pp. eabf9668
Author(s):  
Bingbing Ding ◽  
Liangwei Ma ◽  
Zizhao Huang ◽  
Xiang Ma ◽  
He Tian
Keyword(s):  
Room Temperature ◽  
High Efficiency ◽  
Optoelectronic Devices ◽  
Luminescence Properties ◽  
Quantum Yields ◽  
Room Temperature Phosphorescence ◽  
Trace Impurities ◽  
Mole Percent ◽  
Flexible Application ◽  
Incorporation Method

Pure organic persistent room temperature phosphorescence (RTP) has shown great potential in information encryption, optoelectronic devices, and bio-applications. However, trace impurities are generated in synthesis, causing unpredictable effects on the luminescence properties. Here, an impurity is isolated from a pure organic RTP system and structurally characterized that caused an unusual ultralong RTP in matrix even at 0.01 mole percent content. Inspired by this effect, a series of compounds are screened out to form the bicomponent RTP system by the trace ingredient incorporation method. The RTP quantum yields reach as high as 74.2%, and the lifetimes reach up to 430 ms. Flexible application of trace ingredients to construct RTP materials has become an eye-catching strategy with high efficiency, economy, and potential for applications as well as easy preparation.

scholarly journals Design of polar self-assembling lactic acid derivatives possessing submicrometre helical pitch

2018 ◽  
Vol 9 ◽  
pp. 333-341 ◽  
Author(s):  
Alexej Bubnov ◽  
Cyril Vacek ◽  
Michał Czerwiński ◽  
Terezia Vojtylová ◽  
Wiktor Piecek ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
Alkyl Chains ◽  
Temperature Range ◽  
Helical Pitch ◽  
Self Assembling ◽  
Electro Optic ◽  
Nanoscale Level

Several new lactic acid derivatives containing the keto linkage group far from the chiral part and short alkyl chains have been synthesized and characterised by polarising optical microscopy, differential scanning calorimetry, as well as electro-optic and dielectric spectroscopy. The materials possess a self-assembling behaviour on the nanoscale level as they form polar smectic liquid crystalline mesophases, namely the orthogonal paraelectric SmA* and the tilted ferroelectric SmC* phases, in a broad temperature range down to room temperature. A short helical pitch (≈120–320 nm), relatively high spontaneous polarisation (≈150 nC/cm2) and reasonable tilt angle values have been determined within the temperature range of the tilted ferroelectric SmC* phase. The obtained results make the new materials useful for the advanced mixture design and for further utilisation in electro-optic devices based on the deformed helix ferroelectric effect.

scholarly journals Bicontinuous Cubic and Hexagonal Columnar Liquid Crystalline Ion-Conductors at Room Temperature in Ion-Doped Dendritic Amphiphiles

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 193
Author(s):  
Thi Huyen Do ◽  
Ho-Joong Kim ◽  
Manh Linh Nguyen ◽  
Byoung-Ki Cho
Keyword(s):  
Liquid Crystalline ◽  
Room Temperature ◽  
Molecular Design ◽  
Three Dimensional ◽  
Impedance Analysis ◽  
Practical Applications ◽  
Alkyl Chains ◽  
Bicontinuous Cubic ◽  
Hexagonal Columnar ◽  
Ion Conductors

A bicontinuous cubic (Cubbi) liquid crystalline (LC) phase consisting of three dimensional (3D) conducting networks is a promising structural platform for ion-conductors. For practical applications using this fascinating LC structure, it is necessary to suppress crystallization at room temperature (RT). Herein, we report the Cubbi structure at RT and the morphology–dependent conduction behavior in ionic samples of a non-crystallizable dendritic amphiphile. In the molecular design, branched alkyl chains were used as an ionophobic part instead of crystallizable linear alkyl chains. Two ionic samples with Cubbi and hexagonal columnar (Colhex) LC phases at RT were prepared by adding different amounts of lithium salt to the amphiphile. Impedance analysis demonstrated that the Cubbi phase contributed to the faster ion-conduction to a larger extent than the Colhex phase due to the 3D ionic networks of the Cubbi phase. In addition, the temperature–dependent impedance and electric modulus data provided information regarding the phase transition from microphase-separated phase to molecularly mixed liquid phase.

scholarly journals Guidelines for measurement of luminescence spectra and quantum yields of inorganic and organometallic compounds in solution and solid state (IUPAC Technical Report)

2016 ◽  
Vol 88 (7) ◽  
pp. 701-711 ◽  
Author(s):  
Hitoshi Ishida ◽  
Jean-Claude Bünzli ◽  
Andrew Beeby
Keyword(s):  
Solid State ◽  
Organic Compounds ◽  
Room Temperature ◽  
Inorganic Compounds ◽  
Organometallic Compounds ◽  
Quantum Yields ◽  
Luminescence Spectra ◽  
Room Temperature Phosphorescence ◽  
Emission Data ◽  
Technical Report

AbstractGuidelines for measuring the luminescence of inorganic compounds, metal complexes, and organometallic compounds are described. Common textbooks and manuals describing luminescence measurements are usually targeted for organic compounds, and are not always suitable for inorganic and organometallic compounds, which emit room-temperature phosphorescence. The report describes problems that researchers may confront while recording emission data and elaborates clear procedures to avoid these problems and provide adequate standardized protocols.

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