scholarly journals Accelerated Design of Near-Infrared-II Molecular Fluorophores via First-Principles Understanding and Machine Learning

2021 ◽  
Author(s):  
Shidang Xu ◽  
Pengfei Cai ◽  
Jiali Li ◽  
Xianhe Zhang ◽  
Xianglong Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Energy Gap ◽  
Recent Decade ◽  
Quantum Yields ◽  
Chemical Library ◽  
Practical Applications ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Wide Range ◽  
Fundamental Research

Organic molecular fluorophores in the second near-infrared window (NIR-II) have attracted much attention in the recent decade due to their great potentials in both fundamental research and practical applications. This is especially true for biomedical research, owing to their deep light penetration depth and low bioluminescence background at the long wavelength. However, the fluorescence quantum yields (QY) of most NIR-II materials are very low, which are not ideal for practical applications. Although there is a growing need to discover new NIR-II fluorophores, most of them were designed based on experience, and the structures were limited to few molecular motifs. Herein, we report the design of high QY NIR-II fluorophores in solutions based on enhancing the rigidity of the conjugated backbones, which could be quantified by the Seminario method. A deep neural network was trained to predict the HOMO-LUMO energy gaps for a chemical library of NIR-II backbone structures. Hundreds of new NIR-II cores with low energy gap were discovered, and eight of them across different acceptor cores are found to have relatively rigid conjugated backbones. With further molecular processing or formulation, the proposed new fluorophores should boost the development of NIR-II materials for applications in a wide range of fields.

scholarly journals Towards Blue AIE/AIEE: Synthesis and Applications in OLEDs of Tetra-/Triphenylethenyl Substituted 9,9-Dimethylacridine Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 445 ◽  
Author(s):  
Monika Cekaviciute ◽  
Aina Petrauskaite ◽  
Sohrab Nasiri ◽  
Jurate Simokaitiene ◽  
Dmytro Volyniuk ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Yields ◽  
Yellow Emission ◽  
Blue Color ◽  
Television System ◽  
Fluorescence Quantum Yields ◽  
Deep Blue ◽  
Wide Range ◽  
Cyano Groups ◽  
High Yields

Aiming to design blue fluorescent emitters with high photoluminescence quantum yields in solid-state, nitrogen-containing heteroaromatic 9,9-dimethylacridine was refined by tetraphenylethene and triphenylethene. Six tetra-/triphenylethene-substituted 9,9-dimethylacridines were synthesized by the Buchwald-Hartwig method with relatively high yields. Showing effects of substitution patterns, all emitters demonstrated high fluorescence quantum yields of 26–53% in non-doped films and 52–88% in doped films due to the aggregation induced/enhanced emission (AIE/AIEE) phenomena. In solid-state, the emitters emitted blue (451–481 nm) without doping and deep-blue (438–445 nm) with doping while greenish-yellow emission was detected for two compounds with additionally attached cyano-groups. The ionization potentials of the derivatives were found to be in the relatively wide range of 5.43–5.81 eV since cyano-groups were used in their design. Possible applications of the emitters were demonstrated in non-doped and doped organic light-emitting diodes with up to 2.3 % external quantum efficiencies for simple fluorescent devices. In the best case, deep-blue electroluminescence with chromaticity coordinates of (0.16, 0.10) was close to blue color standard (0.14, 0.08) of the National Television System Committee.

Chlorination vs. fluorination: a study of halogenated benzo[c][1,2,5]thiadiazole-based organic semiconducting dots for near-infrared cellular imaging

2020 ◽  
Vol 44 (19) ◽  
pp. 7740-7748
Author(s):  
Daize Mo ◽  
Li Lin ◽  
Pengjie Chao ◽  
Hanjian Lai ◽  
Qingwen Zhang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cellular Imaging ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Stokes Shifts

The chlorinated dots based on chlorinated benzo[c][1,2,5]thiadiazole unit possess higher fluorescence quantum yields, larger Stokes shifts, and better photostability than the fluorinated dots.

scholarly journals Inverted energy gap law for the nonradiative decay in fluorescent floppy molecules: larger fluorescence quantum yields for smaller energy gaps

2019 ◽  
Vol 6 (12) ◽  
pp. 1948-1954 ◽  
Author(s):  
Junqing Shi ◽  
Maria A. Izquierdo ◽  
Sangyoon Oh ◽  
Soo Young Park ◽  
Begoña Milián-Medina ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Energy Gap ◽  
Quantum Yields ◽  
Nonradiative Decay ◽  
Fluorescence Quantum Yields ◽  
Energy Gaps ◽  
Energy Gap Law ◽  
Solution Increase ◽  
Floppy Molecules ◽  
Franck Condon

The non-radiative decay of substituted dicyano-distyrylbenzenes in solution increase with the Franck–Condon energy, being opposite to the conventional energy gap law.

scholarly journals Shortwave-infrared (SWIR) emitters for biological imaging: a review of challenges and opportunities

Nanophotonics ◽  
2017 ◽  
Vol 6 (5) ◽  
pp. 1043-1054 ◽  
Author(s):  
Elijah Thimsen ◽  
Bryce Sadtler ◽  
Mikhail Y. Berezin
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Materials Science ◽  
Energy Gap ◽  
Tissue Imaging ◽  
Quantum Yields ◽  
Electromagnetic Spectrum ◽  
Surrounding Matrix ◽  
Low Efficiency ◽  
Shortwave Infrared

AbstractShortwave infrared radiation (SWIR) is the portion of the electromagnetic spectrum from approximately 900 nm to 2500 nm. Recent advances in imaging systems have expanded the application of SWIR emitters from traditional fields in materials science to biomedical imaging, and the new detectors in SWIR opened an opportunity of deep tissue imaging. Achieving deep photon penetration while maintaining high resolution is one of the main objectives and challenges in bioimaging used for the investigation of diverse processes in living organisms. The application of SWIR emitters in biological settings is, however, hampered by low quantum efficiency. So far, photoluminescent properties in the SWIR region have not been improved by extending concepts that have been developed for the visible (400–650 nm) and near-infrared (NIR, 700–900 nm) wavelengths, which indicates that the governing behavior is fundamentally different in the SWIR. The focus of this minireview is to examine the mechanisms behind the low efficiency of SWIR emitters as well as to highlight the progress in their design for biological applications. Several common mechanisms will be considered in this review: (a) the effect of the energy gap between the excited and ground state on the quantum efficiency, (b) the coupling of the excited electronic states in SWIR emitters to vibrational states in the surrounding matrix, and (c) the role of environment in quenching the excited states. General strategies to improve the quantum yields for a diverse type of SWIR emitters will be also presented.

scholarly journals A Straightforward Substitution Strategy to Tune BODIPY Dyes Spanning the Near-Infrared Region via Suzuki–Miyaura Cross-Coupling

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1297 ◽  
Author(s):  
Guanglei Li ◽  
Yu Otsuka ◽  
Takuya Matsumiya ◽  
Toshiyuki Suzuki ◽  
Jianye Li ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cross Coupling ◽  
Cumulus Cells ◽  
Infrared Region ◽  
Quantum Yields ◽  
Nir Dyes ◽  
Wide Range ◽  
One Step ◽  
The One ◽  
First Time

In this study, a series of new red and near-infrared (NIR) dyes derived from 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) were developed by introducing thiophene and its derivatives to the 3- and 5- positions of the dichloroBODIPY core. For the first time, cyclictriol boronates and N-methyliminodiacetic acid (MIDA) boronate were used as organoboron species to couple with 3,5-dichloroBODIPY via the one-step Suzuki–Miyaura cross-coupling. Six kinds of thieno-expended BODIPY dyes were synthesized in acceptable yields ranging from 31% to 79%. All six dyes showed different absorption and emission wavelengths spanning a wide range (c.a. 600–850 nm) in the red and NIR regions with relatively high quantum yields (19–85%). Cellular imaging of 8-(2,6-dimethylphenyl)-re3,5-di(2-thienyl)-BODIPY (dye 1) was conducted using bovine cumulus cells, and the fluorescence microscopy images indicated that the chromophore efficiently accumulated and was exclusively localized in the cytoplasm, suggesting it could be utilized as a subcellular probe. All six dyes were characterized using 1H-NMR and mass spectrometry.

Development of an organic dye solution for laser cooling by anti-Stokes fluorescence

2001 ◽  
Vol 667 ◽  
Author(s):  
Jarett L. Bartholomew ◽  
Peter A. DeBarber ◽  
Bauke Heeg ◽  
Garry Rumbles
Keyword(s):  
Laser Cooling ◽  
Organic Dye ◽  
Quantum Yields ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Optical Cooling ◽  
Doped Glasses ◽  
Anti Stokes ◽  
Rhodamine 101 ◽  
Dye Solutions

ABSTRACTSeveral independent groups have observed optical cooling by means of anti-Stokes luminescence in condensed media. The most promising materials are grouped into two categories: ion-doped glasses and organic dye solutions. It is this latter group that we focus our efforts on. Recent studies by our group show that irradiating a solution of rhodamine 101 in the long wavelength wing of the absorption spectrum results in the observation of optical cooling. To improve upon the initial observation of a few degree drop in temperature requires a better understanding of the conditions and phenomena leading to anti-Stokes luminescence in dye solutions. We develop a thermal lensing experiment to obtain fluorescence quantum yields of various dye solutions. The importance of concentration, choice of solvent, deuteration, and acidification are discussed.

Long-Wavelength-Absorbing and -Emitting Carbostyrils with High Fluorescence Quantum Yields

1999 ◽  
Vol 82 (9) ◽  
pp. 1408-1417 ◽  
Author(s):  
Georg Uray ◽  
Karlheinz S. Niederreiter ◽  
Ferdinand Belaj ◽  
Walter M. F. Fabian
Keyword(s):  
Quantum Yields ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

scholarly journals Study on the Physical Properties of Pulsed Laser Deposited Doped Copper Oxide (Cu2 O) Thin Films for Optical Device Applications

2020 ◽  
pp. 1-6
Author(s):  
Gurpreet Kaur ◽  
◽  
Anirban Mitra ◽  
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Energy Gap ◽  
Visible Region ◽  
Pulsed Laser ◽  
Practical Applications ◽  
Wide Range ◽  
Cu2o Films ◽  
Cu2o Thin Films

Cuprous oxide, (Cu2O) is a promising p-type semiconductor, finds practical applications in a wide range of optoelectronic devices. In this paper, pulsed laser deposition technique is employed to deposit doped Cu2O thin films. The influence of doping of silver (Ag), aluminium (Al) and co-doping of (Ag+Al) in Cu2O thin films is illustrated. X-ray diffraction pattern depicts cubic crystal structure and polycrystalline nature of grown thin films, having small crystallite size (~50 nm). Atomic force microscopy (AFM) obtained surface images of the films portrait uniform grain morphology with low surface roughness. The room temperature optical characterizations of the thin films, the transmittance versus wavelength in the UV-Visible region exhibits low transmission values upto 10–20%, illustrates the large absorption coefficient (α), numerical values varying from 104 to 105cm-1 for doped Cu2O films. The large values of absorption coefficient facilitate the optical and photovoltaic applications of the doped Cu2O films. The addition of dopant species Ag and Al, the optical band gap is increased and it varies in the range of 2.65−2.84 eV. The increased energy gap is attributed to the substitution of Al and Ag ions for the oxygen ions reduce the width of valence band to widen the energy gap. The I−V characteristics plot obtained at room temperature indicates low electrical resistivity (ρ ~ 10-2Ω- cm) of the films. The obtained results are of high relevance and indicate potential applications of the grown thin films in semiconductor devices such as solar cells, photodetectors and optical sources

scholarly journals Guest-host doped strategy for constructing ultralong-lifetime near-infrared organic phosphorescence materials for bioimaging

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Fuming Xiao ◽  
Heqi Gao ◽  
Yunxiang Lei ◽  
Wenbo Dai ◽  
Miaochang Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Near Infrared ◽  
Tumor Imaging ◽  
Energy Gap ◽  
Radiative Transition ◽  
Room Temperature Phosphorescence ◽  
Triplet Energy ◽  
Long Wavelength ◽  
Long Lifetime ◽  
First Time

AbstractOrganic near-infrared room temperature phosphorescence materials have unparalleled advantages in bioimaging due to their excellent penetrability. However, limited by the energy gap law, the near-infrared phosphorescence materials (>650 nm) are very rare, moreover, the phosphorescence lifetimes of these materials are very short. In this work, we have obtained organic room temperature phosphorescence materials with long wavelengths (600/657–681/732 nm) and long lifetimes (102–324 ms) for the first time through the guest-host doped strategy. The guest molecule has sufficient conjugation to reduce the lowest triplet energy level and the host assists the guest in exciton transfer and inhibits the non-radiative transition of guest excitons. These materials exhibit good tissue penetration in bioimaging. Thanks to the characteristic of long lifetime and long wavelength emissive phosphorescence materials, the tumor imaging in living mice with a signal to background ratio value as high as 43 is successfully realized. This work provides a practical solution for the construction of organic phosphorescence materials with both long wavelengths and long lifetimes.

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