A5037689324- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organic Light-Emitting Diodes Research
- Luminescence and Fluorescent Materials
- Organic Electronics and Photovoltaics
- Molecular Junctions and Nanostructures
- Molecular spectroscopy and chirality
- Catalytic Cross-Coupling Reactions
- Porphyrin and Phthalocyanine Chemistry
- Photoreceptor and optogenetics research
- Crystallography and molecular interactions
- Alzheimer's disease research and treatments
- Supramolecular Self-Assembly in Materials
- Photochemistry and Electron Transfer Studies
- Nanocluster Synthesis and Applications
- Additive Manufacturing and 3D Printing Technologies
- Amino Acid Enzymes and Metabolism
- Lanthanide and Transition Metal Complexes
- Organometallic Complex Synthesis and Catalysis
- Advanced Sensor and Energy Harvesting Materials
- Radical Photochemical Reactions
- Semiconductor materials and devices
- Inorganic Chemistry and Materials
- Metal complexes synthesis and properties
- Mass Spectrometry Techniques and Applications
University of Cambridge
2017-2021
Cavendish Hospital
2016-2019
Bridge University
2019
The efficiency of an organic light-emitting diode (OLED) is fundamentally governed by the spin recombining electron-hole pairs (singlet and triplet excitons), since triplets cannot usually emit light. singlet-triplet energy gap, a key factor for efficient utilization triplets, normally positive. Here we show that in family materials with amide donor carbene acceptor moieties linked metal, this gap singlet excitons charge-transfer character can be tuned from positive to negative values via...
Multiple donor-acceptor-type carbazole-benzonitrile derivatives that exhibit thermally activated delayed fluorescence (TADF) are the state of art in efficiency and stability sky-blue organic light-emitting diodes. However, such a motif still suffers from low reverse intersystem crossing rates (kRISC ) with emission peaks <470 nm. Here, weak acceptor cyanophenyl is adopted to replace stronger cyano one construct blue emitters multiple donors acceptors. Both linear donor-π-donor...
Harnessing the near-infrared (NIR) region of electromagnetic spectrum is exceedingly important for photovoltaics, telecommunications, and biomedical sciences. While thermally activated delayed fluorescent (TADF) materials have attracted much interest due to their intense luminescence narrow exchange energies (ΔEST), they are still greatly inferior conventional dyes in NIR, which precludes application. This because securing a sufficiently strong donor-acceptor (D-A) interaction NIR emission...
Conformationally flexible "Carbene-Metal-Amide" (CMA) complexes of copper and gold have been developed based on a combination sterically hindered cyclic (alkyl)(amino)carbene (CAAC) 6- 7-ring heterocyclic amide ligands. These show photoemissions across the visible spectrum with PL quantum yields up to 89% in solution 83% host-guest films. Single crystal X-ray diffraction photoluminescence (PL) studies combined DFT calculations indicate important role ring structure conformational flexibility...
Carbene-metal-amide type photoemitters based on CF$_3$-substituted carbazolate ligands show sky-blue to deep-blue photoluminescence from charge-transfer excited states. They are suitable for incorporation into organic light-emitting diodes (OLEDs) by thermal vapour deposition techniques, either embedded within a high-triplet-energy host, or used host-free. We report high-efficiency OLEDs with emission ranging yellow blue (Commission Internationale de l'\'Eclairage (CIE) coordinates [0.35,...
Abstract Carbene metal amides are a new class of highly efficient light‐emitting molecules based on linear donor–metal–acceptor geometry. Here the synthesis, structure, and photo‐ electroluminescence carbene silver carbazolato complexes, ( Ad L)Ag(Cz) [ L = adamantyl‐substituted cyclic (alkyl)(amino)carbene; Cz carbazolate 1 ) 3,6‐ t Bu 2 )], reported. They display green emission with photoluminescence quantum yields up to 74%. Efficient mixing triplet singlet excited states is observed,...
Abstract Efficient vacuum‐processed organic light‐emitting diodes are fabricated using a carbene–metal–amide material, CMA1. An electroluminescence (EL) external quantum efficiency of 23% is achieved in host‐free emissive layer comprising pure Furthermore efficiencies up to 26.9% host–guest layers. EL spectra found depend on both the emissive‐layer doping concentration and choice host enabling tuning emission color from mid‐green (Commission Internationale de l'Éclairage co‐ordinates [0.24,...
Light-emitting carbene-metal amide complexes bearing first- and second-generation carbazole dendron ligands are reported, (AdL)M(Gn), (M = Cu Au; Gn dendrimer generation, where n 1 2; AdL adamantyl-substituted cyclic (alkyl)(amino)carbene). The thermal stability of the increases with each generation. Cyclic voltammetry indicates that highest occupied molecular orbital/lowest unoccupied orbital energy levels largely unaffected by size dendron, while first reduction oxidation processes show a...
The optical characterisation and device functionality for a series of axially modified silicon phthalocyanines (SiPcs) as dopant red emitters in solution-processed vapour-deposited organic light-emitting diodes (OLEDs) is presented.
Energy transfer in star-shaped donor–acceptor molecules reduces self-absorption luminescent solar concentrators.
Significance Intrinsic fluorescence of nonaromatic amino acids is a puzzling phenomenon with an enormous potential in biophotonic applications. The physical origins this effect, however, remain elusive. Herein, we demonstrate how specific hydrogen bond networks can modulate fluorescence. We highlight the key role played by short bonds, present protein structure, on ensuing provide detailed experimental and molecular evidence to explain these unusual optical properties. Our findings should...
Abstract A new family of cyclometallated gold(III) thiolato complexes based on pyrazine‐centred pincer ligands has been prepared, (C^N pz ^C)AuSR, where C^N ^C=2,6‐bis(4‐Bu t C 6 H 4 )pyrazine dianion and R=Ph ( 1 ), Bu‐4 2 2‐pyridyl 3 1‐naphthyl (1‐Np, 2‐Np 5 quinolinyl (Quin, 4‐methylcoumarinyl (Coum, 7 ) 1‐adamantyl 8 ). The were isolated as yellow to red solids in high yields using mild synthetic conditions. single‐crystal X‐ray structures revealed that the colour deep‐red is associated...
Abstract Carbene‐metal‐amides (CMAs) are a promising family of donor–bridge–acceptor molecular charge‐transfer (CT) emitters for organic light‐emitting diodes. A universal approach is demonstrated to tune the energy their CT emission. blueshift up 210 meV achievable in solid state via dilution polar host matrix. The origin this shift has two components: constraint thermally‐activated triplet diffusion, and electrostatic interactions between guest host. This allows emission mid‐green CMA...
Organic emitters exhibiting delayed fluorescence (DF) are promising luminescent materials for next-generation organic light-emitting diodes (OLEDs). Faster intersystem crossing rates and shorter emission lifetimes can be achieved in molecules through the incorporation of heavy atoms, which enhance spin–orbit coupling promote between singlet triplet states. DF often contain a sulfur atom, reports selenium-containing OLEDs also exist. However, literature lacks direct exploration effect on...
There is a growing body of experimental work showing that protein aggregates associated with amyloid fibrils feature intrinsic fluorescence. In order to understand the microscopic origin this behavior observed in non-aromatic peptides and proteins, we conducted combined computational study on optical properties amyloid-derived oligopeptides near-UV region. We have focused few model systems having charged termini (zwitterionic) or acetylated termini. For zwitterionic system, were able...
Abstract Fluorescence in biological systems is usually associated with the presence of aromatic groups. Here, we show that specific hydrogen bonding networks can significantly affect fluorescence employing a combined experimental and computational approach. In particular, reveal single amino acid L-glutamine, by undergoing chemical transformation leading to formation short bond, displays optical properties are enhanced compared L-glutamine itself. Ab initio molecular dynamics simulations...
Abstract: It has been previously found that through an established synthesis of the macrocycle boron subnaphthalocyanine (BsubNc) random bay-position chlorination occurs and results in a mixed alloyed composition cannot be separated; called chloro-(chloro n )-boron subnaphthalocyanines (Cl-Cl BsubNcs). Through modifications synthetic method, amounts average can varied. Cl-Cl BsubNcs are fluorescent therefore here we explore effect amount on photoluminescent electroluminescent properties...
We combine absorption and fluorscence spectroscopy experiments theoretical modeling to specifically examine the role of termini interactions on optical properties.Optical fluorescence is measured for a six-chain amino acid 2Y3J (AIIGLM) which forms segment full amyloid beta 1-40. In order explore sensitivity properties interactions, were repeated by acetylating N-terminus.Although atomic force microscopy indicate formation some form fibrilar or crystal aggregates in both systems, are...
Carbene-metal-amides (CMA) are an exciting class of materials for high-efficiency organic light-emitting diodes. In article number 1802285, Dan Credgington and co-workers demonstrate that vacuum-processing can be successfully used to fabricate CMA devices with tunable emission color high external quantum efficiency (EQE) up 26.9%, including host-free achieving EQE 23%.