One-axis Two-wing Guest-Host Strategy for Constructing Ultralong-lifetime Near-infrared Organic Phosphorescence Materials for Bioimaging

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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Aggregation-induced emission (AIE)-active molecules bearing singlet oxygen generation activities: the tunable singlet–triplet energy gap matters

Chemical Communications ◽

10.1039/c8cc09230c ◽

2019 ◽

Vol 55 (10) ◽

pp. 1450-1453 ◽

Cited By ~ 16

Author(s):

Chengkai Zhang ◽

Yanqian Zhao ◽

Dandan Li ◽

Jiejie Liu ◽

Heguo Han ◽

...

Keyword(s):

Singlet Oxygen ◽

Cell Apoptosis ◽

Near Infrared ◽

Energy Gap ◽

Intersystem Crossing ◽

Triplet Energy ◽

Oxygen Generation ◽

Two Photon ◽

Singlet Oxygen Generation ◽

Infrared Excitation

Two-photon active photosensitizers showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation.

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Beating the Limitation of Energy Gap Law Utilizing Deep Red MR-TADF Emitter with Narrow Energy-Bandwidth

10.26434/chemrxiv.13202975 ◽

2020 ◽

Author(s):

Yuewei Zhang ◽

Dongdong Zhang ◽

Tianyu Huang ◽

Guomeng Li ◽

Chen Zhang ◽

...

Keyword(s):

High Performance ◽

Near Infrared ◽

Energy Gap ◽

Organic Light Emitting Diodes ◽

Vibrational Coupling ◽

Light Emitting ◽

Radiative Processes ◽

Energy Gap Law ◽

Mr Effect ◽

Peripheral Skeleton

The development of high-performance deep red/near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. Herein, a novel BN-containing skeleton featuring linear N-π-N and B-π-B structure is developed, establishing partial bonding/antibonding character on phenyl core for enhanced electronics coupling of para-positioned B atoms as well as N atoms to narrow energy gaps. Also, the remained MR effect on the peripheral skeleton to maintain the MR effect to minimize the bonding/ antibonding character and suppress vibrational coupling between S0 and S1, thereby fundamentally overcoming the luminescent boundary set by the energy gap law. The target molecules R-BN and R-TBN exhibited extremely high PLQYs of 100% with emission wavelengths at 666 and 686 nm, respectively. The narrow FWMHs of 38 nm observed also testify the effectiveness of vibronic suppression. The corresponding OLEDs afford record-high EQEs over 28% with emission wavelength over 664 nm.

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

Materials ◽

10.3390/ma11081297 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1297 ◽

Cited By ~ 5

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.

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Theoretical tuning of the singlet–triplet energy gap to achieve efficient long-wavelength thermally activated delayed fluorescence emitters: the impact of substituents

Physical Chemistry Chemical Physics ◽

10.1039/c7cp02615c ◽

2017 ◽

Vol 19 (32) ◽

pp. 21639-21647 ◽

Cited By ~ 7

Author(s):

Lijuan Wang ◽

Tao Li ◽

Peicheng Feng ◽

Yan Song

Keyword(s):

Energy Gap ◽

Delayed Fluorescence ◽

Triplet Energy ◽

Thermally Activated Delayed Fluorescence ◽

Long Wavelength ◽

Thermally Activated ◽

The Impact ◽

Electron Withdrawing Substituents

Long-wavelength TADF emitters could be achieved with both small ΔEST and high kr through introducing small electron-withdrawing substituents!

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One-Photon Upconversion-Like Photolysis: A New Strategy to Achieve Long-Wavelength Light-Excitable Photolysis

Synlett ◽

10.1055/s-0040-1707100 ◽

2020 ◽

Vol 31 (12) ◽

pp. 1129-1134 ◽

Cited By ~ 2

Author(s):

Weiping Wang ◽

Wen Lv

Keyword(s):

Near Infrared ◽

Energy Utilization ◽

Utilization Efficiency ◽

Infrared Light ◽

Excitation Wavelength ◽

Long Wavelength ◽

New Strategy ◽

The One ◽

Biological And Medical Applications ◽

Wavelength Light

Photolysis reactions are widely utilized to release desired molecules under the control of light irradiation in the fields of photochemistry, biology, and drug delivery. In biological and medical applications, it is highly desired to increase the excitation wavelength for activating photolysis reactions, since the long-wavelength light (red or near-infrared light) has deep tissue penetration depth and low photocytotoxicity. Here, we briefly summarize current strategies of achieving long-wavelength light-excitable photolysis. We highlight our recently developed strategy of one-photon upconversion-like photolysis. Compared with the multiphoton upconversion-based photolysis, the one-photon strategy has a simpler energy transfer process and a higher energy utilization efficiency, providing a new path of activating photolysis reactions with increased excitation wavelength and photolysis quantum yield.

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Indirect Red and Near-Infrared Z-to-E Photoisomerization of ortho-Functionalized Azobenzenes via Triplet Energy Transfer

10.26434/chemrxiv.14134595 ◽

2021 ◽

Author(s):

Jussi Isokuortti ◽

Kim Kuntze ◽

Matti Virkki ◽

Zafar Ahmed ◽

Elina Vuorimaa-Laukkanen ◽

...

Keyword(s):

Energy Transfer ◽

Spectral Range ◽

Near Infrared ◽

Triplet Energy ◽

Long Wavelength ◽

Whole Process ◽

Infrared Spectral Range ◽

Porphyrin Photosensitizers ◽

Infrared Spectral ◽

Triplet Energy Transfer

Designing azobenzene photoswitches capable of selective and efficient photoisomerization by long wavelength excitation is a long-standing challenge. Indirect excitation can expand the properties of the photoswitching system beyond the intrinsic limits of azobenzenes. Herein, a rapid Z-to-E isomerization of two ortho-functionalized azobenzenes with near-unity photoconversion was facilitated via triplet energy transfer upon red and near-infrared (up to 770 nm) excitation of porphyrin photosensitizers in catalytic micromolar concentrations. Our results indicate that the whole process of triplet-sensitized isomerization is strongly entropy-driven. This ensures efficient Z-to-E photoswitching even when the azobenzene triplet energy is considerably higher (>200 meV) than for the sensitizer, which is the key for the expansion of excitation wavelengths into the near-infrared spectral range.

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Beating the Limitation of Energy Gap Law Utilizing Deep Red MR-TADF Emitter with Narrow Energy-Bandwidth

10.26434/chemrxiv.13202975.v1 ◽

2020 ◽

Author(s):

Yuewei Zhang ◽

Dongdong Zhang ◽

Tianyu Huang ◽

Guomeng Li ◽

Chen Zhang ◽

...

Keyword(s):

High Performance ◽

Near Infrared ◽

Energy Gap ◽

Organic Light Emitting Diodes ◽

Vibrational Coupling ◽

Light Emitting ◽

Radiative Processes ◽

Energy Gap Law ◽

Mr Effect ◽

Peripheral Skeleton

The development of high-performance deep red/near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. Herein, a novel BN-containing skeleton featuring linear N-π-N and B-π-B structure is developed, establishing partial bonding/antibonding character on phenyl core for enhanced electronics coupling of para-positioned B atoms as well as N atoms to narrow energy gaps. Also, the remained MR effect on the peripheral skeleton to maintain the MR effect to minimize the bonding/ antibonding character and suppress vibrational coupling between S0 and S1, thereby fundamentally overcoming the luminescent boundary set by the energy gap law. The target molecules R-BN and R-TBN exhibited extremely high PLQYs of 100% with emission wavelengths at 666 and 686 nm, respectively. The narrow FWMHs of 38 nm observed also testify the effectiveness of vibronic suppression. The corresponding OLEDs afford record-high EQEs over 28% with emission wavelength over 664 nm.

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Expanding Azobenzene Photoswitching into Near-Infrared via Endothermic Triplet Energy Transfer

Chemical Science ◽

10.1039/d1sc01717a ◽

2021 ◽

Author(s):

Jussi Isokuortti ◽

Kim Kuntze ◽

Matti Virkki ◽

Zafar Ahmed ◽

Elina Vuorimaa-Laukkanen ◽

...

Keyword(s):

Energy Transfer ◽

Near Infrared ◽

Triplet Energy ◽

Long Wavelength ◽

Triplet Energy Transfer

Azobenzene photoswitches capable of selective and efficient photoisomerization by long-wavelength excitation is an enduring challenge. Herein, rapid isomerization from Z- to E-state of two ortho-functionalized bistable azobenzenes with near-unity photoconversion...

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Multiple Resonance Deep-red Emitters with Hybridized π-bonding/ non-bonding Orbitals to Surpass the Energy Gap Law

10.21203/rs.3.rs-119314/v1 ◽

2021 ◽

Author(s):

Yuewei Zhang ◽

Dongdong Zhang ◽

Tianyu Huang ◽

Alexander Gillett ◽

Yang Liu ◽

...

Keyword(s):

Radiative Decay ◽

Near Infrared ◽

Energy Gap ◽

Light Emitting Diode ◽

Resonance Effect ◽

Infrared Region ◽

Decay Rates ◽

Quantum Yields ◽

Multiple Resonance ◽

Energy Gap Law

Abstract Efficient organic emitters in the deep-red to near infrared region are rare due to the ‘energy gap law’. Here, multiple boron (B)- and nitrogen (N)-atoms embedded polycyclic heteroaromatics featuring hybridized π-bonding/ non-bonding molecular orbitals are constructed, providing a way to overcome the above luminescent boundary. The introduction of B-phenyl-B and N-phenyl-N structures enhances the electronic coupling of those para-positioned atoms, forming restricted π-bonds on the phenyl-core for delocalized excited states and thus a narrow energy gap. The mutually ortho-positioned B- and N-atoms also induce a multiple resonance effect on the peripheral skeleton for the non-bonding orbitals, creating shallow potential energy surfaces to eliminate the high-frequency vibrational quenching. The corresponding deep-red emitters with peaks at 662 nm and 692 nm exhibit narrow full-width at half-maximums of 38 nm, high radiative decay rates of ~108 s-1, ~100% photo-luminance quantum yields and record-high maximum external quantum efficiencies of >28% in a normal planar organic light-emitting diode structure, simultaneously.

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