JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Ksenofontov Alexander A.,Berezin Michail B.,Bocharov Pavel S.,Khodov Ilya A.,Miloshevskaya Olga V.,Antina Elena V.
The search for fluorophores with intense absorption and emission in the red region of the spectrum is an important task, as such compounds can be used in fluorescence imaging, providing high image resolution due to the deep penetration of low energy photons into tissues. In this paper, we present the results of the synthesis and photophysical characterization of a novel ms -benzimidazole-4,4′,5,5′-tetramethyldipyrromethene bis (difluoroborate) ( BOIMPY ) compound, which exhibits intensive absorption and emission in the long-wavelength region while maintaining high fluorescence quantum yields (up to 60%). Using DFT analysis, we investigated the geometry of BOIMPY in both ground and excited states and described the influence of the molecular structure on its practically relevant photophysical properties.
研究领域:
化学
·
材料科学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2013
·
IF 1.959
Yiwei Xu,Xinbing Chen,Fengqi Zhao,Xuezhong Fan,Pei Chen,Zhongwei An
The synthesis and characterisation, and mesomorphic and photophysical properties of a new type of benzoxazole-terminated heterocyclic compounds, 2-(4ʹ-alkoxybiphenyl-4-yl)-benzoxazole derivatives (nB-x), are reported. For better understanding of the structure–property relationships, compounds bearing a variety of polar substituents in the 5-position of the benzoxazole moiety were prepared, including H (nB-H), NO2 (nB-N), CH3 (nB-M) and Cl (nB-C). Their phase transition behaviour was investigated by differential scanning calorimetry and polarising optical microscopy. In the case of carbon atoms in the alkoxy chain between 2 and 10 they exhibited enantiotropic smectic mesophases, for which the mesophase ranges were 101–175°C and 159–182°C on heating and cooling for nB-N, 5–63°C and 19–63°C for nB-H, 81–90°C and 78–96°C for nB-M, and 131–132°C and 131–132°C for nB-C, respectively. The effect of the length of the alkoxy chain on mesomorphic properties was studied. Compounds nB-N, nB-M and nB-C exhibited a much wider mesophase range either on heating or cooling than the corresponding nB-H series, which indicated that the substituent on the benzoxazole moiety was helpful in increasing the mesophase stability. Substituents with stronger electron-withdrawing properties gave a wider mesomorphic temperature domain, in the order NO2 > Cl > CH3 > H, which was similar to the effect of the substituents on the UV absorption bands of nB-x. The opposite effect was found for the corresponding Schiff base liquid crystals (nS-x). With the exception of nB-N, the nB-x series displayed intense photoluminescence emission in methylene chloride solution, with absorption maxima within the range 395–404 nm.
研究领域:
材料化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2021
·
IF 15.419
Zhuang Hu,Yufei Shu,Haiyan Qin,Xiaofei Hu,Xiaogang Peng
With high-quality CdSe/CdS core/shell nanocrystals as the main model system and under a controlled atmosphere, responses of photoexcited semiconductor nanocrystals to two active species (water and/or oxygen) in an ambient environment are studied systematically. Under photoexcitation, although high-quality semiconductor nanocrystals in either thin solid films or various solutions have a near-unity photoluminescence quantum yield, there is still a small probability (∼10–5 per photon absorbed) to be photoreduced by the water molecules efficiently accumulated in the highly hydrophilic nanocrystal–ligands interface. The resulting negatively charged nanocrystals are the starting point of most photophysical variations, and the hydroxyl radical─key photo-oxidation product of water─plays the main role for initiating various photochemical processes. Depending on the supplementation of water to the interface, accessibility to oxygen, photoirradiation power, type of matrices, type of measurement schemes, and solubility of nanocrystals in the solution, various photophysical/photochemical phenomena─either reported or not reported in the literature─are reproducibly observed. Results confirm that photophysical properties and photochemical reactions can be well-correlated, offering a unified and unique basis for fundamental studies and the design of processing techniques in industry.
研究领域:
材料科学
·
光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Daocheng Hong,Weiqing Yang,Yuxi Tian
Organometal halide perovskites have been one of the most promising alternative semiconductors in photovoltaic and light-emitting devices due to their excellent optoelectronic properties. However, the photophysical processes in these hybrid perovskites are still not fully understood. Photoluminescence (PL) of perovskite materials has been one of the most popular methods to investigate the photophysical processes in these materials. However, the PL signal only provides information of the radiative recombination of the charge carriers, which is not sufficient to understand the full picture of the photophysics. For example, both PL quenching and degradation of the materials cause decrease of PL intensity, which cannot be distinguished by PL. In this work, by simultaneously monitoring the absorption and PL of CH3NH3PbI3 perovskite during the photoexcitation with the assistance of microscopic technology, we followed the PL variation and the absorption change at the same time, allowing us to directly distinguish the PL quenching effect and structure change of the materials. These results provide us an effective way to investigate the perovskite materials from different aspects and further promote the understanding of their physical processes.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2020
·
IF 4.231
Ben Dong,Tao Shi,Yun Lu
A series of new monomers (M1~M6) containing both thiophene and indole structures and carrying different substituents with varied electronic effects on the 2,3-position of indole have been designed and synthesized. The corresponding conjugated polymers (P1~P6) obtained via oxidative polymerization presented different spectral phenomena and fluorescence properties as well as fluorescence lifetime due to the synergistic influence of varied electronic effects, the interaction between polymer chains and π-π stacking of indole moieties. By adjusting the properties of substituents and their position in indole ring, these as-prepared conjugated polymers can emit fluorescence with varied colors such as blue-green, yellow, orange-red, brown red, light red and red, and show the changes of fluorescence intensity in different degrees with the increase of 365 nm UV irradiation time. Among them, P3 and P5 show much stronger fluorescence than other species, which is very desirable for application.
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2022
·Vol. 131
·期 14
·
IF 2.877
Chen Guifeng,Du Qinghua,Zhang Hui,Niu Ruotong,Yuan Wenhao,Xie Xinjian,Guo Tianyu,Liu Guodong
Quantum dots of I–III–VI ternary compounds exhibit unusual photophysical properties and technological utility, which attract attention and have been intensely investigated. CuInSe 2 quantum dots are an environmentally friendly composition, a direct transition, and an adjustable bandgap. Here, we discuss the influence of the Cu/In molar ratio of CuInSe 2 quantum dots on Cu-related defects and photo-physical properties, and CuInSe 2 quantum dots are synthesized by a green, safe, and low-temperature method in triethylene glycol. The proportion of the +1 and +2 oxidation states of Cu in the quantum dots will change with the Cu/In molar atomic ratio. The +1-oxidation state of Cu will prolong the carrier recombination lifetime and provide favorable conditions for the transfer and collection of carriers. By adjusting for different defect types, we can better apply CISe quantum dots in devices and other fields.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 46
·e202404170
·
IF 1.9
Pengtao Sheng,Haiyan Xu,Yaqi Zhang,Haiyue Xia,Haipeng Liu,Weili Li
Graphical We present a surfactant-associated controlled synthesis of copper (Cu)-deficient zinc (Zn)-doped Cu-indium (In)-selenium (Se) QDs, followed by a mechanistic investigation of their photophysical properties using surfactants. The findings described here are expected to provide a general strategy for enhancing the tunability of photophysical properties in other QDs systems. The shape and size-controlled synthesis of colloidal I−III−VI quantum dots (QDs) can be attained only by a few synthesis strategies via the introduction of various high-boiling-point organic surfactants. To further investigate this strategy, in this study, we present a surfactant-associated controlled synthesis of copper (Cu)-deficient, zinc (Zn)-doped Cu─indium (In)─selenium (Se) QDs, followed by a mechanistic investigation of their photophysical properties using surfactants, such as oleylamine (OLA), oleic acid (OA), and diphenylphosphine (DPP). OLA significantly promoted the quantum size effect-resultant emission wavelength red-shift, while OA controlled the homogeneous growth of QDs and improved the quantum yields. Moreover, Gaussian deconvolution of the photoluminescence spectra and the bandgap derived from the absorption spectra, by fitting, supported the fact that the radiative transition channels, especially for surface-trap-state-related transitions, are also dependent on the surfactants. Specifically, the conduction band electron-intragap state transitions and donor-acceptor transitions were present in all the prepared samples but accounted for different percentages. Furthermore, the surface-trap-state-related transitions significantly faded upon adding (i) OLA/OA as the sole surfactant to the cationic precursor and (ii) the OA + OLA + DPP mixture to the anionic precursor. The findings described here are expected to provide a general strategy for enhancing the tunability of photophysical properties in other QDs systems.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2016
·Vol. 11
·期 18
·2555-2563
·
IF 4.592
Yafei Wang,Wanhui Liu,Jiyong Deng,Guohua Xie,Yuanwei Liao,Zuoming Qu,Hua Tan,Yu Liu,Weiguo Zhu
Pi-conjugated organic molecules featuring the donor–bridge–acceptor (D–π–A) structure have been widely used in semiconducting materials owing to their rigid structure, good thermal stability, excellent charge transfer, and high emission efficiency. To investigate the effect of the D–π–A molecular structure on the photophysical properties, in this contribution, three star-shaped D–π–A isomers based on the 2,4,6-triphenyl-1,3,5-triazine, spirofluorene, and triphenylamine moieties, that is, p -TFTPA, mp -TFTPA, and m -TFTPA, were synthesized by elaborately engineering the interconnecting position in the building-block units. The optophysical properties of these compounds were systematically explored by experiments and theory calculations. Definitively, changing the interconnecting position in these molecules played a significant role in the degree of π conjugation, which resulted in tunable emission colors from deep blue to green. Moreover, these isomers were employed as emissive dopants in organic light-emitting diodes. The highest external quantum efficiency of 2.3 % and current efficiency of 6.2 cd A −1 were achieved by using the p -TFTPA based device. This research demonstrates a feasible way to realize blue emitters by engineering D–π–A conjugation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 39
·5964-5968
·
IF 3.304
Bang-Chang Zhu,Wei-Hui Fang,Perumal Emayavaramban,Lei Zhang,Jian Zhang
We herein report the synthesis and structures of two salicylate-stabilized polyoxo-titanium clusters (PTCs) with and without fluorine, namely, H2[Ti13(μ3-O)7(μ2-O)4(Sal-F)9(OiPr)14] (PTC-95, H2Sal-F = 5-fluorosalicylic acid) and H2[Ti14(μ3-O)8(μ2-O)4(Sal)8(OiPr)18]·HOiPr (PTC-96, H2Sal = salicylic acid). Structural analyses indicated that PTC-95 is a fairly compact structure made up of a quadrangular prism with an appended linear Ti3 cluster and two additional Ti atoms. PTC-96 possesses an arch bridge-shaped structure linked by two Ti4(μ3-O)2 and two Ti3(μ3-O) clusters. Apart from the intrinsic structural features, their diverse photocurrent response properties and photocatalytic activities towards dye degradation were also demonstrated.
研究领域:
无机化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2017
·Vol. 33
·期 7
·1390-1398
·
IF 0.767
YIN Lu,LIANG Cheng,CHEN Ke-Xian,ZHAO Chen-Xuan,YAO Jia,Li Hao-Ran
A novel Pt(II)-based metallointercalator terpyridine complex linked with a 2,2,6,6-tetramethyl-1-piperidinyl N-oxide (TEMPO) derivative was prepared by a reaction between 4'-TEMPO-terpyridine (L) and a Pt(II) salt. This complex presented unusual luminescence quenching owing to
the effect of the stable nitroxide radical. The crystal structure of[Pt(terpy-TEMPO)Cl]Cl·H2O·CH3OH (terpy=2,2':6',2"-terpyridine) was elucidated by X-ray crystallography. Additionally, the effect of TEMPO on the photophysical properties of[Pt(terpy-TEMPO)Cl]
Cl·H2O·CH3OH was investigated by UV-Vis, fluorescence emission, and electron paramagnetic resonance (EPR) spectroscopy. Data from the absorption and luminescence properties (298 K) of the[Pt(terpy-TEMPO)Cl]+ complex indicated the presence of two
groups of typical bands:an intense band B with distinct vibronic structures (270-350 nm, ε>104 dm3·mol-1·cm-1) and a less intense band A (370-450 nm, ε~103 dm3·mol-1·cm-1).
These two bands are generally assigned to ligand-to-ligand charge transfer (LLCT) and metal-to-ligand charge transfer (MLCT) excited states, respectively. Furthermore, efficient photoluminescent quenching behavior was observed in the emission spectra of this complex system. Quantum calculations
of the molecular energy gaps and bands were performed by Gaussian 09 software. The calculated results verified that TEMPO greatly affects the energy gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. Thus, the relationship between efficient photoquenching
and molecular structure was theoretically interpreted. EPR results indicated that when TEMPO is attached to a macrocyclic terpyridine platinum complex, e.g.,[Pt(terpy)Cl]+, the terpyridine platinum complex does not affect the hyperfine coupling constant (A value) and g
factor (g values) but the rotation and relaxation times of the TEMPO radical.
研究领域:
无机化学
·
材料科学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Qian Li,Yue Xu,Wei He,Yuan Fang Li,Peng Fei Gao,Cheng Zhi Huang
Core-shell materials have superior properties over their single-component counterparts, and thus how to develop a new type of core-shell structure deserves much hard work. Herein, a plasmon-dependent photophysical (PDPP) process was developed to prepare [email protected] T core-shell nanostructures with reversible properties, wherein Safranine T (ST) was at first adsorbed on the surface of negatively charged gold nanospheres (AuNSs) through the electrostatic attraction and then controllably deposited by adjusting plasmonic illumination. The whole PDPP process was monitored in real-time via dark field microscopy (DFM) imaging system, verifying that plasmon-dependent light-matter interaction occurs. The as-prepared [email protected] nanostructures were then successfully applied for a reversible process of edit and erase that was suitable for encryption application with nanosized precision. This research showed that the PDPP process has high promise for developing precise structures of new materials, particularly those through nanoprocessing and nanooperation.
研究领域:
纳米材料科学
·
光学工程
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 11
·5330-5337
·
IF 3.3
Yu Wang,Rao Chen,Dongmei Liu,Chaofei Peng,Junwei Wang,Xiaoqing Dong
The development of effective Vis-sensitive photoinitiators for light-emitting diode (LED) polymerization is still an emerging challenge as LEDs are being developed into the predominant light sources. In this work, a series of new functionalized photoinitiators, containing thioxanthones and oxime-esters as functional groups, was designed and straightforwardly synthesized in two steps. The structures of the photoinitiators were studied using 1H NMR, 13C NMR, and high-resolution mass spectrometry. The conclusion of the photophysical properties indicated that the long wavelength absorptions from 360 nm to 405 nm made the investigated thioxanthone derivatives quite appealing as a valuable photoinitiator under UV-Vis LEDs. The structure–reactivity relationship was also studied in detail through real-time FTIR spectroscopy. A possible photolysis mechanism was expected based on further photolysis and online 1H NMR activities. With a proper molecular design, the new functionalized photoinitiators were synthesised straightforwardly and they displayed more advanced initiation abilities than their parent thioxanthone.
研究领域:
材料化学
·
光化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）