ORGANIC & BIOMOLECULAR CHEMISTRY
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2018
·Vol. 16
·期 31
·5598-5608
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IF 3.423
Yaxiong Wei,Min Zheng,Qiaohui Zhou,Xiaoguo Zhou,Shilin Liu
A bodipy–C70 dyad was synthesized and applied in triplet–triplet annihilation (TTA) upconversion of perylene as a novel metal-free organic photosensitizer. The photophysical processes were investigated by the methods of steady-state UV-Vis absorption and fluorescence spectroscopy, nanosecond time-resolved transient absorption spectroscopy, cyclic voltammetry, and density functional theory calculations. The bodipy–C70 dyad showed an increased molar extinction coefficient up to 82 300 mol−1 cm−1 at 518 nm compared with the C70 monomer. With photo-excitation of the bodipy moiety at 532 nm, the intramolecular singlet–singlet energy transfer between bodipy and C70 units was efficient with a quantum yield of nearly 100%, and the lowest triplet state of the dyad was subsequently populated via ISC of the C70 moiety, with a lifetime of ca. 80 μs in toluene. Electrochemical investigation suggested that the intramolecular electron transfer of the excited dyad was thermodynamically prohibited in toluene due to the positive ΔGCS for charge-separation. With the presence of perylene in solution as the triplet energy acceptor and emitter, the TTA upconverted fluorescence was observed with a maximum quantum yield of 10.3%. The overall upconversion capability of 4417 M−1 cm−1 exceeded that of C70 approximately two-fold. Moreover, the bodipy–C70 dyad also exhibited an enhanced optical stability under intense irradiation. All data indicated that the dyad was another ideal photosensitizer for TTA upconversion of perylene in the fullerene derivative family.
研究领域:
材料科学
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光化学
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DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 31
·11763-11771
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IF 4.052
Yaxiong Wei,Min Zheng,Lin Chen,Xiaoguo Zhou,Shilin Liu
Three Os(II) complexes were synthesized with ligands 2,2′-dipyridyl (dipy), 1,10-phenanthroline monohydrate (phen), and 4,7-diphenyl-1,10-phenanthroline (diphen), and applied as triplet photosensitizers for triplet–triplet annihilation (TTA) fluorescence upconversion. The strong spin-orbital coupling made direct spin-forbidden transition of S0–T1 feasible. Lifetimes of the lowest triplet state of these complexes were determined to be 107 ns, 373 ns, and 386 ns for Os-dipy, Os-phen, and Os-diphen, respectively, using nanosecond transient absorption spectra. From steady-state phosphorescence emission spectra, energies of the triplet states were derived to be 1.75 eV, 1.80 eV, and 1.74 eV for Os-dipy, Os-phen, and Os-diphen, respectively. Using these photosensitizers, strong upconverted fluorescence of the triplet acceptors, 9,10-diphenylanthracene (DPA), perylene, and 9,10-bis(phenethynyl) anthracene (BPEA), was observed in the visible to violet range. In particular, fluorescence emission with the largest anti-Stokes shift of 1.14 eV was observed for the Os-phen/DPA system, and the upconverted quantum yield was determined as 5.9% in deoxygenated dichloroethane. Additionally, upconversion was determined in air using mixtures of dichloroethane and DMSO solvents, and the maximal quantum yield was measured to be 4.5% for Os-phen/DPA.
研究领域:
化学
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材料科学
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光物理学
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DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Syed S. Razi,Yun Hee Koo,Woojae Kim,Wenbo Yang,Zhijia Wang,Habtom Gobeze,Francis D’Souza,Jianzhang Zhao,Dongho Kim
A boron dipyrromethane (BDP)-containing Pt(II)–Schiff base complex (Pt-BDP), showing ping-pong singlet–triplet energy transfer, was synthesized, and the detailed photophysical properties were investigated using various steady-state and time-resolved transient spectroscopies. Femtosecond/nanosecond transient absorption spectroscopies demonstrated that, upon selective excitation of the BDP unit in Pt-BDP at 490 nm, Förster resonance energy transfer from the BDP unit to the Pt(II) coordination center occurred (6.7 ps), accompanied by an ultrafast intersystem crossing at the Pt(II) coordination center (<1 ps) and triplet–triplet energy transfer back to the BDP moiety (148 ps). These processes generated a triplet state localized at BDP, and the lifetime was 103.2 μs, much longer than the triplet-state lifetime of Pt-Ph (3.5 μs), a complex without the BDP moiety. Finally, Pt-BDP was used as a triplet photosensitizer for triplet–triplet annihilation (TTA) upconversion through selective excitation of the BDP unit or the Pt(II) coordination center at lower excitation energy. An upconversion quantum yield of up to 10% was observed with selective excitation of the BDP moiety, and a large anti-Stokes shift of 0.65 eV was observed upon excitation of the lower-energy band of the Pt(II) coordination center. We propose that using triplet photosensitizers with the ping-pong energy-transfer process may become a useful method for increasing the anti-Stokes shift of TTA upconversion.
研究领域:
化学
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光物理学
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Yonggang Yang,Tingting Ye,Yang Liu,Zhinan Jiang,Tiantian Guan,Chaochao Qin,Chunsheng Zhuang,Yufang Liu
Triphenylamine (TPA) molecules are extensively employed in optoelectronic materials and photochemical reactions. The present research examines the ultrafast dynamics of photocyclization reaction utilizing transient absorption (TA) spectroscopy. In the femtosecond TA spectrum, the excited state absorption (ESA) signal for TPA at 627 nm diminishes within 2.5 ns, while a triplet-triplet absorption (TTA) signal emerges at 524 nm, gradually decaying over 25.2 ns in the subsequent nanosecond TA spectrum. As the TTA signal diminishes, a new positive TTA signal corresponding to the photocyclization intermediate, N-phenyl-4a,4b-dihydrocarbazole (NPDHC), appears at 426 nm. Following the decay of the TTA signal of NPDHC over 494.5 ns, another positive absorption signal is observed at 612 nm, which is associated with the ESA signal from both NPDHC and N-phenylcarbazole. In contrast, Tetra-N-phenylbenzidine (TPB) and N,N′-Bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPB-CH 3 ) exhibit only a positive ESA signal and a negative stimulated emission (SE) signal, with no detectable TTA signal or cyclization product signal. Theoretical simulations reveal that the spin-orbit coupling (SOC) constant of TPA (0.26 cm −1 ) is higher than that of the two other molecules (0.09 cm −1 ). This research presents direct observations of the triplet-triplet intermediates in the photocyclization reaction of TPA in real-time.
研究领域:
化学动力学
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光化学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2019
·
IF 2.961
Qiuhong Wang,Ming Xu,Wei Feng,Fuyou Li
Upconversion based on triplet-triplet annihilation (TTA-UC) has received much attention due to its unique ability to effectively harvest low-energy photons in the solar spectrum for widespread investigations involving energy, environment, and bioapplication. However, the utilization of conventional TTA-UC systems for low-power bioimaging in vivo is still a challenge due to their incompatibility and moderate efficiency in aqueous media. Herein, we pioneer the molecular modification strategy by introducing steric hindrance to the BODIPY annihilators to realize robust TTA-UC in biocompatible nanocapsule . The improved molecules could maintain excellent luminescence even at a very high concentration wherein the separation distance between neighbouring chromophores was reduced to facilitate the pivotal process of Dexter energy transfer. In this way, the encapsulated TTA-UC system became highly efficient in biological circumstance with quantum efficiency Ф UC of 6.3%. Consequently, the constructed nanocapsule was capable of operating at low-power with high contrast for in vivo imaging.
研究领域:
生物化学
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材料科学
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医学影像学
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DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 62
·36410-36415
·
IF 3.049
Shuoran Chen,Fuming Chen,Pengju Han,Changqing Ye,Suqin Huang,Lei Xu,Xiaomei Wang,Yanlin Song
A ratiometric fluorescent sensor for the detection of Fe3+ ions is achieved based on triplet–triplet annihilation upconversion (TTA-UC) luminescence. A new anthracene derivative (named as DHTPA) is designed and synthesized and reveals similar optical properties to 9,10-diphenylanthracene (DPA) and is used as a stimuli responsive annihilator in a TTA-UC system due to its complexation ability. As a result, the UC emission can be significantly quenched by Fe3+ ions, while the phosphorescence (PL) emission of sensitizer palladium(II) octaetylporphyrin (PdOEP) remains nearly constant, which makes the PL signal an appropriate internal reference for the UC signal. The UC and ratio signals (IUC/IPL) both reveal a good linear relationship with Fe3+ ion concentration, which for the first time makes the TTA-UC system a perfect ratiometric sensor for Fe3+ ion detection. This sensing method will open a novel avenue to achieve ratiometric sensors in chemical and biological fields.
研究领域:
化学
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生物传感
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材料科学
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DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2022
·Vol. 223
·期 14
·2200038
·
IF 2.996
Qiang Fu,Jiaqiang Rui,Jiaojiao Fang,Yaru Ni,Liang Fang,Chunhua Lu,Zhongzi Xu
Due to low penetration ability of ultraviolet (UV) light, UV-induced free radical reactions of polymers are limited to the preparation of thin-layer materials such as coatings and inks. Although upconversion (UC) nanomaterials that can be excited by near-infrared (NIR) light and emit UV light which is used to achieve polymerization or curing of monomers or prepolymers, low quantum efficiency and high excitation threshold limit their applications. Here, triplet-triplet annihilation up-conversion luminescent (TTA-UCL) chromophores of platinum (II) octaethylporphyrin (PtOEP) and 9,10-diphenylanthracene (DPA) are used to realize TTA-UCL-assisted photoinitiated polymerization of butyl acrylate (BA) and ethoxylated trimethylolpropane triacrylate (ETPTA) as well as photo curing of polyurethane acrylates (PUA) using visible light at 520 nm. The effects of chromophores concentrations and incident light power density on double-bond conversion rate are investigated. The results show that a mediate TTA-UCL chromophore concentration of 0.02% is beneficial for polymerization of ETPTA- co -BA with thickness of 25 mm within 15 min. Satisfied adhesion of colored plastic substrates using PUA prepolymers can be achieved after irradiation for 30 s when chromophore concentration of 0.1% is used. TTA-UCL assisted photoinitiated reactions show great potential in engineering aspects including quick repair of leaking tubes and photocuring of adhesives underwater.
研究领域:
材料科学
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高分子化学
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光化学
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DOI
高影响因子
Journal of Physical Chemistry Letters
·
2022
·
IF 6.888
Yonggang Yang,Zhinan Jiang,Yang Liu,Tiantian Guan,Qi Zhang,Chaochao Qin,Kai Jiang,Yufang Liu
Real-time monitoring of singlet–triplet transitions is an effective tool for studying room-temperature phosphorescent molecules. For femtosecond transient absorption (TA) spectroscopy of a 2,6-di(9H-carbazol-9-yl) pyridine molecule in dimethyl sulfoxide (DMSO), the stimulated emission signal (380 nm) and the excited-state absorption signal (650 nm) reach their maximum intensity within 397 fs. Subsequently, the two signals decay with time and the triplet–triplet absorption (TTA) signal (400 nm) is enhanced synchronously, accompanied by an isosbestic point at 491 nm. These results confirm intersystem crossing (ISC) within 2.5 ns. Moreover, the TTA signal (400 nm) in nanosecond TA spectroscopy gradually disappeared, accompanied by a phosphorescence lifetime of 4.1 μs. As the solvent polarity decreases (DMSO > N,N-dimethylformamide > 1,4-dioxane > toluene), similar spectral dynamic processes are observed, while the durations of ISC processes and phosphorescence lifetimes are shortened. This combined femtosecond and nanosecond transient absorption spectroscopy study presents the ultrafast excited-state dynamics of organic phosphorescent molecules.
研究领域:
物理化学
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光谱学
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材料科学
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有机电子学
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光物理
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DOI
高影响因子
Journal of Analysis and Testing
·
2023
·Vol. 7
·期 4
·369-376
·
IF 4.7
Chen Shuoran,Chen Fuming,Li Yanling,Wang Yuyang,Wang Xiaomei,Ye Changqing
A derivative of fluorescein, fluorescein O,O-diacrylate (FODA), was utilized in a triplet–triplet annihilation upconversion (TTA-UC) system to develop a composite ratiometric chemosensor capable of detecting cysteine (Cys). FODA acted as both the probe for Cys and the energy acceptor for upconversion (UC) emission, thereby making UC a responsive signal to Cys. In addition, the phosphorescence signal of the sensitizer in the TTA-UC system remained constant and did not respond to Cys, making it an ideal internal reference signal for constructing a ratiometric sensor. Through this simple strategy, traditional fluorescent probes can be combined with TTA-UC system to establish a ratiometric sensing platform, which can be applied in more scenarios due to the longer wavelength excitation.
研究领域:
分析化学
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生物传感
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医学诊断
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 24
·8325-8331
·
IF 5.721
Jiaojiao Fang,Yukai Chen,Cheng Zhu,Xue Li,Wei Wang,Chunhua Lu,Yaru Ni,Liang Fang,Zhongzi Xu
Strong upconversion luminescence is significant for effective photocatalytic technology. In this work, photonic crystals and Au nanoparticles (AuNPs) were introduced together to enhance triplet–triplet annihilation upconversion (TTA-UC) luminescence intensity. Photonic crystal films have been fabricated by demolding a polydimethylsiloxane film containing platinum(II)-octaethylporphyrin & 9,10-diphenylanthracene and AuNPs from V-shape anodic aluminum oxide templates. The blue light intensity of the photonic crystal film with AuNPs has gained a 3.69-fold enhancement under green light excitation. After coupling the photonic crystal structure with AuNP plasma resonance, the green-to-blue TTA-UC intensity of the composite film has been enhanced 7.68 times compared with the planar upconversion film without AuNPs. The pseudo-first-order rate constant of the composite film system with g-C3N4@CdS has been increased 3.88 times compared with that of the planar upconversion film system without AuNPs under visible light. This work presents a new route to enhance the TTA-UC luminescence via a hybrid effect, which is useful for photocatalysis.
研究领域:
材料科学
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光化学
·
纳米技术
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2025
·
IF 3.7
Shigang Wan,Dongxuan Wang,Yizhong Shi,Shuoran Chen,Changqing Ye
Graphical Two photochemically deoxygenating compounds, PEG-200 and PEGDA-575, have been used as solvents for triplet-triplet annihilation upconversion in air, with both serving as sensitized singlet oxygen scavengers. A high-level information encryption platform has been developed using Pt(OEP)/DPA/PEGDA-575 or Pt(OEP)/DPA/PEGDA-575/PEG-200 ink that enables data to be read under specific light or at a certain time and erased by light exposure. Photochemical deoxygenation offers a promising solution to the oxygen sensitivity issue in Triplet-triplet annihilation upconversion (TTA-UC). This study utilized polyethylene glycol (PEG)-200 and polyethylene glycol diacrylate (PEGDA)-575 as solvents and singlet oxygen scavengers for TTA-UC conducted in air. The upconversion efficiency of Pt(OEP)/DPA in aerated PEG-200 is similar to that in nitrogen-saturated PEG-200. Prolonged 532 nm light irradiation causes a PEGDA-575 solution of Pt(OEP)/DPA to undergo photoinitiated polymerization via homomolecular TTA, leading to a reduction in DPA's upconversion emission and an increase in Pt(OEP)’s phosphorescence. These results enabled the development of a high-level information encryption platform using the direct-writing method with Pt(OEP)/DPA/PEGDA-575 or Pt(OEP)/DPA/PEGDA-575/PEG-200 ink. The information is only readable under certain lighting conditions or at specific times and can be erased by exposure to light.
研究领域:
材料科学
·
光学
·
化学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Jiaojiao Fang,Yukai Chen,Wei Wang,Liang Fang,Chunhua Lu,Cheng Zhu,Jiahui Kou,Yaru Ni,Zhongzi Xu
Herein we first coupled a wide photo-response photocatalyst with plasmon-enhanced triplet − triplet annihilation upconversion (TTA-UC) nanoparticles for photocatalytic hydrogen generation. The plasmon-based enhancement of TTA-UC was achieved by introducing Au nanoparticles into the core liquid of TTA-UC nanoparticles containing platinum(II)-octaethylporphyrin and 9,10-diphenylanthracene. Au-TTA nanoparticles encapsulated by silica shells significantly increased the green-to-blue upconversion compared with TTA nanoparticles. The silica shells after further surface functionalization can conjoin with photocatalysts. To improve the stability of cadmium sulfide (CdS), graphitic carbon nitride (g-C 3 N 4 ) was combined with CdS for g-C 3 N 4 -CdS heterojunctions. g-C 3 N 4 -CdS sheets based on Au-enhanced TTA-UC can utilize the upconverted high-energy photons and thereby realized efficient photocatalytic hydrogen production. Au-TTA nanoparticles conjoined with g-C 3 N 4 -CdS reached a high hydrogen production of 16.88 mmol g −1 under visible-light irradiation and an apparent quantum efficiency of 1.439% under green-light irradiation. The study provides a new TTA-supported upconversion-photocatalysis system enhanced by Au plasmon resonance effect for effectively hydrogen generation.
研究领域:
材料科学
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光化学
·
纳米技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）