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oe1(光电查) - 科学论文

46 条数据
?? 中文(中国)
  • Long-lived triplet excited state in a platinum( <scp>ii</scp> ) perylene monoimide complex

    摘要: We report the synthesis and solution based photophysical properties of a new Pt(II)-terpyridine complex coupled to a perylene monoimide (PMI) chromophoric unit through an acetylene linkage. This structural arrangement resulted in quantitative quenching of the highly fluorescent PMI chromophore by introducing metal character into the lowest energy singlet state, thereby leading to the formation of a long-lived PMI-ligand localized triplet excited state (τ = 8.4 μs). Even though the phosphorescence from this triplet state was not observed, highly efficient quenching of this excited state by dissolved oxygen and the observation of singlet oxygen photoluminescence in the near-IR at 1270 nm initially pointed towards triplet excited state character. Additionally, the coincidence of the excited state absorbance difference spectra from the sensitized PMI ligand using a triplet donor and the Pt-PMI complex provided strong evidence for this triplet state assignment, which was further supported by TD-DFT calculations.

    关键词: singlet oxygen,perylene monoimide,photophysics,platinum(II) complex,triplet excited state

    更新于2025-11-19 16:56:42

  • Synthesis and characterization of novel benzodithiophene-fused perylene diimide acceptors: Regulate photovoltaic performance via structural isomerism

    摘要: Two isomeric benzodithiophene-fused perylene diimides, BPDI-1 and BPDI-2, are designed and synthesized via photo-induced ring-closure reaction between perylene diimide (PDI) acceptor and both isomeric benzodithiophene donor cores, including benzo[2,1-b:3,4-b']dithiophene (BDP) and benzo[1,2-b:4,3-b']dithiophene (BdT). The effect of structural isomerism on the molecular geometry, absorption, energy level, film morphology as well as photovoltaic performance is comparatively studied. It is found that the variation of the S atom substituted position in the donor cores results in distinct molecular geometries for the newly-developed BPDI-1 and BPDI-2 acceptors. Compared with BDP-containing BPDI-1, the incorporation of BdT core endows BPDI-2 with a remarkably enhanced backbone distortion. When blended with the commercially available polymer donor (PTB7-Th), such twisted structure feature for the BPDI-2 acceptor plays a key role in reducing molecule aggregation, which is helpful for the enhancements of short-circuit current density and photovoltaic efficiency effectively. As a result, non-fullerene solar cells fabricated from BPDI-2 acceptor achieve higher photovoltaic efficiency (4.44%) than that of BPDI-1 (2.98%), mainly benefited from superior short-circuit current density. This work provides us comparative understanding of isomeric geometry and device performance.

    关键词: Benzodithiophene,Molecular geometry,Non-fullerene organic solar cells,Perylene diimide derivatives

    更新于2025-11-19 16:56:42

  • Assembly structure and free energy change of a chromonic liquid crystal formed by a perylene dye

    摘要: The nematic (chromonic N) and isotropic phases formed by aqueous solutions of a perylene dye are investigated by x-ray diffraction and visible light absorption spectroscopy. X-ray diffraction shows that the molecules assemble into columns one molecule wide. The change in the visible absorption spectrum with concentration indicates that the molecules stack in a more or less isodesmic manner and that the free energy change associated with the addition or removal of a single molecule from a stack is 16–20 kBT. This range is appreciably higher than those of any previously-measured simple chromonic systems, i.e. those with single molecule-wide columns. It is suggested that the large free energy change promotes the formation of extremely long columns of molecules, and in turn leads to the low concentration at which mesophase formation takes place.

    关键词: chromonic,isodesmic,scission energy,perylene dye,assembly structure,lyotropic chromonic,Liquid crystals

    更新于2025-11-19 16:56:35

  • Benzo[ghi]perylene & Coronene as Ratiometric Reversible Optical Oxygen Nano-Sensor

    摘要: The development of novel single molecular probe based optical ratiometric oxygen sensor with simple fabrication, high sensitivity, and linear response is highly desirable. Herein, benzo[ghi]perylene (BzP) and coronene (Cron) were explored as dual-emissive ratiometric oxygen nano-sensor that displayed linear plots at a low probe concentration (6 μM). The sensor fabrication was simple, and the probes exhibited efficient fluorescence quenching of monomer emission by molecular oxygen. However, the excimer emission of probe remained unaffected. Thus a ratiometric method is developed based on the dual emitting luminophore. The method can be used to estimate dissolved oxygen in liquids and 5 – 100 % of oxygen concentration in gaseous mixtures.

    关键词: Coronene,Benzo[ghi]perylene,Oxygen sensing,Excimer emission,Ratiometric sensor,Fluorescence probe

    更新于2025-11-14 17:04:02

  • Visible-light-triggered generation of persistent radical anions from perylenediimides: A substituent effect and potential application in photocatalytic reduction of Ag+

    摘要: Three perylenediimide derivatives were reduced to their persistent radical anions in N-methyl-2-pyrrolidone (NMP) under ambient conditions by a visible light photoinduced electron transfer (PET). UV?vis and electron paramagnetic resonance (EPR) measurements were carried out to confirm the formation of radicals. The relationships between molecular structure, electrochemical property, phototransformation kinetics, and air stability of radical anions were investigated by the introduction of pyrimidine rings at the core position and fluoroalkylation substituents at the imide position. This study reveals that the electron-deficient pyrimidine rings and electron-withdrawing fluoroalkylation substituents can effectively enhance the phototransformation rate and the radical stability at ambient conditions. The effects of solvents and illuminance levels on the photoinduced reduction of perylenediimides were also studied. A photocatalytic reduction of Ag+ was successfully carried out using the perylenediimide with pyrimidine and fluoroalkylation substituents as catalyst upon irradiation with visible light.

    关键词: Photocatalytic reduction,Perylene diimide derivative,Silver ion,Persistent radical anion,Visible light irradiation

    更新于2025-11-14 17:03:37

  • Modification of TiO <sub/>2</sub> (1?1?0)/organic hole transport layer interface energy levels by a dipolar perylene derivative

    摘要: Our photoemission study reveals that the work function of TiO2(1 1 0) decreases by up to 1.5 eV upon deposition of 9-(bis-(p-(tert-octyl)phenyl)amino)-perylene-3,4-dicarboxylic anhydride (BOPA-PDCA). This effect is attributed to a chemical reaction of TiO2(1 1 0) and the molecular anhydride group, as well as the molecular dipole. Analysis of the film thickness dependent photoemission and metastable atom electron spectroscopy data reveals that for low coverage the perylene backbone of BOPA-PDCA is almost parallel to the substrate surface and higher coverage leads to an orientational transition to essentially upright standing molecules. Comparing the energy-level alignment between TiO2(1 1 0) and the hole transport materials N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) without and with the BOPA-PDCA interlayer, we find that the perylene derivative has a positive impact on the level alignment for dye-sensitized solar cells with high open-circuit voltages.

    关键词: solid state dye-sensitized solar cell,titanium dioxide,energy-level alignment,ultraviolet photoelectron spectroscopy,metastable atom electron spectroscopy,perylene

    更新于2025-09-23 15:23:52

  • Black phosphorus nanosheets based sensitive protease detection and inhibitor screening

    摘要: Proteases, as one of the most significant kind of digestive enzymes, are closely related to a variety of physiological processes and diseases. Herein, a black phosphorus nanosheets (BPs) based sensitive fluorometric method for protease detection and inhibitor screening is proposed. The aqueous solution of perylene probe (probe 1) displays a strong fluorescence. BPs, as novel discovered two-dimensional (2D) materials, can adsorb probe 1 through electrostatic interactions, which causes fluorescence quenching of probe 1. Histone can control the interactions between the perylene probe and BPs, which can be further regulated by the introduction of a protease. Thus, the protease activity can be monitored by detecting the fluorescence intensity changes of probe 1. The method is label free, sensitive and selective. As low as 1 ng/mL trypsin can be easily detected.

    关键词: trypsin,inhibitor,protease,black phosphorus nanosheets,fluorescence,perylene probe

    更新于2025-09-23 15:23:52

  • Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation

    摘要: The nucleophilic addition of methanol and other alcohols to 1,1-diphenylethylene (1) and styrene (6) into the Markovnikov- and anti-Markovnikov-type products was selectively achieved with 1-(N,N-dimethylamino)pyrene (Py) and 1,7-dicyanoperylene-3,4:9,10-tetracarboxylic acid bisimide (PDI) as photoredox catalysts. The regioselectivity was controlled by the photocatalyst. For the reductive mode towards the Markovnikov-type regioselectivity, Py was applied as photocatalyst and triethylamine as electron shuttle. This approach was also used for intramolecular additions. For the oxidative mode towards the anti-Markovnikov-type regioselectivety, PDI was applied together with Ph–SH as additive. Photocatalytic additions of a variety of alcohols gave the corres- ponding products in good to excellent yields. The proposed photocatalytic electron transfer mechanism was supported by detection of the PDI radical anion as key intermediate and by comparison of two intramolecular reactions with different electron density. Representative mesoflow reactor experiments allowed to significantly shorten the irradiation times and to use sunlight as “green” light source.

    关键词: perylene bisimide,photochemistry,pyrene,photocatalysis,electron transfer

    更新于2025-09-23 15:21:21

  • Non-fullerene small molecule acceptors with three-dimensional thiophene/selenophene-annulated perylene diimides for efficient organic solar cells

    摘要: Three-dimensional non-fullerene acceptors with a spiro core linked with S/Se fused perylene diimides possess appropriate energy levels, twisted molecular configuration and high carrier mobility, leading to a power conversion efficiency of 6.95% for the organic solar cells.

    关键词: perylene diimides,organic solar cells,carrier mobility,non-fullerene acceptors,spiro core

    更新于2025-09-23 15:21:01

  • Perylene Diimide Based Conjugated Polymers for All Polymer Solar Cells

    摘要: For recent decades, non-fullerene acceptors (NFAs) are undergoing rapid development and emerging as a hot area in the field of organic solar cells. Among the high performance nonfullerene acceptors, aromatic diimide based electron acceptors remain to be the highly promising systems. This review discusses the important progress of perylene diimide (PDI)-based polymers as nonfullerene acceptors (NFAs) in all polymer solar cells (all-PSCs) since 2014. The relationship between structure and property, matching aspects between donors and acceptors and device fabrications are unveiled from a synthetic chemist perspective.

    关键词: nonfullerene acceptors (NFA),all-polymer solar cells (all-PSCs),energy levels,perylene diimide (PDI),PCE

    更新于2025-09-23 15:21:01