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1.
Xu CJ Li BG Wan JT Bu ZY 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,82(1):159-163
A polymerizable ligand, 5-acrylamido-1,10-phenanthroline (L), was synthesized. Its Eu(III) complex with 2-thenoyltrifluoroacetone (HTTA) was prepared and characterized by elemental analysis, IR, MS, and 1H NMR spectra. The photophysical properties of the complex were studied in detail by using UV, luminescence spectra, luminescence lifetime and quantum yield. The complex shows a remarkable luminescence quantum yield at room temperature (40.1%) upon ligand excitation and a long 5D0 lifetime (590 μs), which makes it not only a promising light-conversion molecular device but also an excellent luminescent polymer precursor. 相似文献
2.
Paul T. Ludford III Shenghua Yang Marcela S. Bucardo Prof. Yitzhak Tor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(13):e202104472
A new fluorescent ribonucleoside alphabet (mthN) consisting of pyrimidine and purine analogues, all derived from methylthieno[3,4-d]pyrimidine as the heterocyclic core, is described. Large bathochromic shifts and high microenvironmental susceptibility of their emission relative to previous alphabets derived from thieno[3,4-d]pyrimidine (thN) and isothiazole[4,3-d]pyrimidine (tzN) scaffolds are observed. Subjecting the purine analogues to adenosine deaminase, guanine deaminase and T7 RNA polymerase indicate that, while varying, all but one enzyme tolerate the corresponding mthN/mthNTP substrates. The robust emission quantum yields, high photophysical responsiveness and enzymatic accommodation suggest that the mthN alphabet is a biophysically viable tool and can be used to probe the tolerance of nucleoside/tide-processing enzymes to structural perturbations of their substrates. 相似文献
3.
Kaivin Hadidi Prof. Dr. Yitzhak Tor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(30):e202200765
Analogues of N,N-dimethyladenine exploiting both thieno-and isothiazolo-pyrimidine cores were modified with 3-subsituted azetidines to yield visibly emissive and responsive fluorophores. The emission quantum yields, among the highest seen for purine analogues (0.64 and 0.77 in water and dioxane respectively), correlated with the Hammett inductive constants of the substituents on the azetidine ring. Ribosylation of the difluoroazetidino-modified nucleobase yielded an emissive nucleoside that displayed a substantially lower emission quantum yield in water, compared to the precursor nucleobase. Importantly, high emission quantum yield was restored in deuterium oxide, which highlights the potential impact of the sugar moiety on the photophysical features of fluorescent nucleosides, a functionality usually considered non-chromophoric and photophysically benign. 相似文献
4.
Amino Acid–Porphyrin Conjugates: Synthesis and Study of their Photophysical and Metal Ion Recognition Properties
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Albish K. Paul Suneesh C. Karunakaran Joshy Joseph Danaboyina Ramaiah 《Photochemistry and photobiology》2015,91(6):1348-1355
Synthesis, photophysical and metal ion recognition properties of a series of amino acid‐linked free‐base and Zn‐porphyrin derivatives (5–9) are reported. These porphyrin derivatives showed favorable photophysical properties including high molar extinction coefficients (>1 × 105 m ?1 cm?1 for the Soret band), quantum yields of triplet excited states (63–94%) and singlet oxygen generation efficiencies (59–91%). Particularly, the Zn‐porphyrin derivatives, 6 and 9 showed higher molar extinction coefficients, decreased fluorescence quantum yields, and higher triplet and singlet oxygen quantum yields compared to the corresponding free‐base porphyrin derivatives. Further, the study of their interactions with various metal ions indicated that the proline‐conjugated Zn‐porphyrins (6 and 9) showed high selectivity toward Cu2+ ions and signaled the recognition through changes in fluorescence intensity. Our results provide insights on the role of nature of amino acid and metallation in the design of the porphyrin systems for application as probes and sensitizers. 相似文献
5.
Gyurim Park Seung Yeon Yi Jaehun Jung Dr. Eun Jin Cho Dr. Youngmin You 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17790-17799
The photoredox catalytic coupling of halomethyl arenes to bibenzyl derivatives has been demonstrated. The catalytic protocol employed the Hantzsch ester, potassium phosphate, and a photoactive cyclometalated IrIII complex catalyst. A photochemical quantum yield as high as 20 % was obtained. The catalytic mechanism was investigated in detail by performing photophysical and electrochemical measurements, as well as by quantum chemical calculations. The results suggest that two‐electron mediation might be responsible for the improved photon economy. The reaction protocol was compatible with halomethyl arenes that contain a variety of functional groups. Finally, the synthetic utility of our protocol was demonstrated by the preparation of a natural dihydrostilbenoid, brittonin A. 相似文献
6.
8-vinyl-adenosine (8VA) is a new fluorescent nucleoside analogue with improved spectroscopic properties as compared to 2-aminopurine (2AP). To further understand its photophysics, we analyzed by the time-dependent density functional theory and the configuration interaction single method, the electronic properties, and transitions of 8VA in its free form and stacked with one or two flanking bases. For free 8VA, the predicted excited-state energy gaps, absorbance peak position, and oscillator strength were found to be in excellent agreement with the experimentally determined ones. Moreover, its high fluorescence quantum yield was found to be associated with the dipole-allowed S1 --> S0 transition. Stacking of 8VA with C, T, or A in dimers or trimers resulted in fluorescence quenching through mechanisms that depend on the nature and relative orientation of the flanking base(s). When 8VA is stacked with T, quenching mainly results from nonradiative relaxation to low-lying dark excited state(s) that do not exist in free 8VA. When 8VA is stacked with A, quenching results mainly from mixing of the molecular orbitals in the ground state. Both types of quenching are thought to accompany the stacking of 8VA with C. In addition, the C-8VA-C trimer was found to exhibit a low-lying S1 emissive state that may generate an increased fluorescence quantum yield and lifetime. The predicted photophysical properties of the trimers are highly consistent with the spectroscopic data of a series of 15-mer oligonucleotides differing only by the nature of the residues flanking the central 8VA. 相似文献
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9.
Cui X Zhang HM Wu TF Li M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,82(1):126-131
In this paper, we report a phosphorescent Ir(III) emitter of Ir(acac-F6)(F-BT)2, where acac-F6 = 1,1,1,5,5,5-hexafluoropentane-2,4-dione and F-BT = 2-(2-fluorophenyl)benzo[d]thiazole, including its crystal structure, electronic nature, photophysical characteristics, thermal and electrochemical properties. Data suggest that Ir(acac-F6)(F-BT)2 is a promising emitter with high quantum yield of 0.19 and good thermal stability, along with its proper energy levels for charge carrier transportation. Electroluminescence (EL) devices using Ir(acac-F6)(F-BT)2 as emitter are also fabricated, and their electroluminescence performances are investigated in detail. The optimal EL device shows a maximum luminance of 27,000 cd/cm2 and a peak current efficiency of 8.7 cd/A. 相似文献
10.
Piermaria Pinter Johannes Soellner Prof. Dr. Thomas Strassner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(64):14495-14499
Platinum(II) complexes with an N-heterocyclic carbene and a cyclometalating phenyl ligand (C^C*) are excellent candidates as efficient blue triplet emitters for OLED applications. The electronic and photophysical properties of these complexes can be fine-tuned with the objective to increase the quantum yields and lower the phosphorescence decay times. We found that platinum complexes with an imidazopyrazine C^C* ligand and bulky acetylacetonates are sky-blue triplet emitters, characterised by an almost unitary quantum yield and short phosphorescence decay times. 相似文献
11.
以三(4-溴苯)胺、4-氨基苯硼酸频哪醇酯、4-二乙氨基水杨醛和三氟化硼乙醚溶液为原料,经过Suzuki偶联反应、缩合反应和配位反应,设计、合成了一种新型三枝结构的三苯胺有机硼配合物(TPAB),使用 1H和 13C NMR对 TPAB的结构进行了表征,通过紫外可见吸收光谱和荧光发射光谱详细研究了TPAB溶液和固体态的光物理性能以及不同的外部条件对其发光性能的影响。发现 TPAB溶液和固体态都具有较强的荧光发射,在四氢呋喃溶液中的吸收峰位于 417 nm,发射峰位于 548 nm,荧光量子产率为 40.49%,荧光寿命为 1.72 ns;TPAB 固体的荧光发射峰位于 582 nm,荧光量子产率为 11.43%,荧光寿命为 0.72ns,表明TPAB具有优良的双光发光性能。此外,TPAB具有良好的发光稳定性,不受pH、金属离子、氨基酸和压力的影响。基于化合物优异的发光性能,将其应用于荧光细胞成像,在肝癌细胞(HepG2)中表现出良好的单光子和双光子荧光成像效果。 相似文献
12.
以三(4-溴苯)胺、4-氨基苯硼酸频哪醇酯、4-二乙氨基水杨醛和三氟化硼乙醚溶液为原料,经过Suzuki偶联反应、缩合反应和配位反应,设计、合成了一种新型三枝结构的三苯胺有机硼配合物(TPAB),使用1H和13C NMR对TPAB的结构进行了表征,通过紫外可见吸收光谱和荧光发射光谱详细研究了TPAB溶液和固体态的光物理性能以及不同的外部条件对其发光性能的影响。发现TPAB溶液和固体态都具有较强的荧光发射,在四氢呋喃溶液中的吸收峰位于417 nm,发射峰位于548 nm,荧光量子产率为40.49%,荧光寿命为1.72 ns; TPAB固体的荧光发射峰位于582 nm,荧光量子产率为11.43%,荧光寿命为0.72ns,表明TPAB具有优良的双态发光性能。此外,TPAB具有良好的发光稳定性,不受pH、金属离子、氨基酸和压力的影响。基于化合物优异的发光性能,将其应用于荧光细胞成像,在肝癌细胞(HepG2)中表现出良好的单光子和双光子荧光成像效果。 相似文献
13.
Yuxin Xiao Hailan Wang Zongliang Xie Mingyao Shen Rongjuan Huang Yuchen Miao Guanyu Liu Tao Yu Wei Huang 《Chemical science》2022,13(31):8906
Near-infrared (NIR) light-emitting materials show excellent potential applications in the fields of military technology, bioimaging, optical communication, organic light-emitting diodes (OLEDs), etc. Recently, thermally activated delayed fluorescence (TADF) emitters have made historic developments in the field of OLEDs. These metal-free materials are more attractive because of efficient reverse intersystem crossing processes which result in promising high efficiencies in OLEDs. However, the development of NIR TADF emitters has progressed at a relatively slower pace which could be ascribed to the difficult promotion of external quantum efficiencies. Thus, increasing attention has been paid to NIR TADF emitters. In this review, the recent progress of NIR TADF emitters has been summarized along with their molecular design strategies and photophysical properties, as well as electroluminescence performance data of their OLEDs, respectively.This review presents the recent progress of NIR TADF emitters along with their molecular design strategies and photophysical properties, as well as the electroluminescence performance data of the emitters and their OLEDs. 相似文献
14.
Yuetao Yang Prof. Dr. Junjia Li Xiaojun Liu Prof. Dr. Shuyi Zhang Prof. Dr. Kris Driesen Dr. Peter Nockemann Dr. Koen Binnemans Prof. Dr. 《Chemphyschem》2008,9(4):600-606
The photophysical properties of lanthanide complexes have been studied extensively; however, fundamental parameters such as the intrinsic quantum yield as well as radiative and nonradiative decay rates are difficult or even impossible to measure experimentally. Herein, a photoacoustic (PA) method is proposed to determine the intrinsic quantum yield of lanthanide complexes with lifetimes in the order of milliseconds. This method is used to determine the intrinsic quantum yields for europium(III)‐containing metallomesogens as well as terbium(III) complexes. The results show that the PA signal is sensitive to both the lifetime and the ratio of the fast‐to‐slow heat component of the samples. It is found that there is an efficient ligand sensitization and a moderate intrinsic quantum yield for the complexes. The intrinsic quantum yield of Eu3+ in the metallomesogens exhibits an obvious increase upon the isotropic liquid to smectic A transition. The proposed PA method is quite simple, and can contribute to a clearer understanding of the photophysical processes in luminescent lanthanide complexes. 相似文献
15.
Dr. Maning Liu Hannu Pasanen Dr. Harri Ali-Löytty Dr. Arto Hiltunen Dr. Kimmo Lahtonen Syeda Qudsia Dr. Jan-Henrik Smått Prof. Mika Valden Prof. Nikolai V. Tkachenko Assoc. Prof. Paola Vivo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22301-22309
Colloidal lead-free perovskite nanocrystals have recently received extensive attention because of their facile synthesis, the outstanding size-tunable optoelectronic properties, and less or no toxicity in their commercial applications. Tin (Sn) has so far led to the most efficient lead-free solar cells, yet showing highly unstable characteristics in ambient conditions. Here, we propose the synthesis of all-inorganic mixture Sn-Ge perovskite nanocrystals, demonstrating the role of Ge2+ in stabilizing Sn2+ cation while enhancing the optical and photophysical properties. The partial replacement of Sn atoms by Ge atoms in the nanostructures effectively fills the high density of Sn vacancies, reducing the surface traps and leading to a longer excitonic lifetime and increased photoluminescence quantum yield. The resultant Sn-Ge nanocrystals-based devices show the highest efficiency of 4.9 %, enhanced by nearly 60 % compared to that of pure Sn nanocrystals-based devices. 相似文献
16.
Dönüs Tuncel Müge Artar Saltuk Bugra Hanay 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4894-4899
The effects of cucurbit[n]uril on the dissolution and the photophysical properties of nonionic conjugated polymers in water are described. For this purpose, a fluorine‐based polymer, namely, poly[9,9‐bis{6(N,N‐dimethylamino)hexyl}fluorene‐co‐2,5‐thienylene (PFT) was synthesized and characterized by spectroscopic techniques including 1D and 2D NMR, UV–vis, fluorescent spectroscopy, and matrix‐assisted laser desorption mass spectrometry (MALDI‐MS). For the first time, it was demonstrated that a nonionic conjugated polymer can be made soluble in water through an inclusion complex formation with CB8. The structure of the complex was elucidated by NMR experiments including 1H and selective 1D‐NOESY. This complex emits green and is highly fluorescent with fluorescent quantum yield of 35%. In contrast, CB6 or water‐soluble CB7 although they are chemically identical to CB8 do not have any effect on the dissolution and photophysical properties of PFT. By preparing a protonated version of PFT, the optical properties of PFT in methanol, protonated PFT and PFT@CB8 in water have been studied and compared. It was also observed that the morphology of the polymer PFT was affected by the presence of CB8. Thus CB8‐assisted self‐assembly of polymer chains leads to vesicles formation; these structures were characterized by DLS, AFM, SEM, and TEM fluorescent optical microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
17.
A Three‐Component Assembly Promoted by Boronic Acids Delivers a Modular Fluorophore Platform (BASHY Dyes)
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Fábio M. F. Santos Dr. João N. Rosa Dr. Nuno R. Candeias Cátia Parente Carvalho Ana I. Matos Ana E. Ventura Dr. Helena F. Florindo Dr. Liana C. Silva Dr. Uwe Pischel Dr. Pedro M. P. Gois 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1631-1637
The modular assembly of boronic acids with Schiff‐base ligands enabled the construction of innovative fluorescent dyes [boronic acid salicylidenehydrazone (BASHY)] with suitable structural and photophysical properties for live cell bioimaging applications. This reaction enabled the straightforward synthesis (yields up to 99 %) of structurally diverse and photostable dyes that exhibit a polarity‐sensitive green‐to‐yellow emission with high quantum yields of up to 0.6 in nonpolar environments. These dyes displayed a high brightness (up to 54 000 m ?1 cm?1). The promising structural and fluorescence properties of BASHY dyes fostered the preparation of non‐cytotoxic, stable, and highly fluorescent poly(lactide‐co‐glycolide) nanoparticles that were effectively internalized by dendritic cells. The dyes were also shown to selectively stain lipid droplets in HeLa cells, without inducing any appreciable cytotoxicity or competing plasma membrane labeling; this confirmed their potential as fluorescent stains. 相似文献
18.
Chunyan Du Shanghui Ye Jianming Chen Yunlong Guo Yunqi Liu Prof. Dr. Kun Lu Ying Liu Ting Qi Dr. Xike Gao Dr. Zhigang Shuai Prof. Dr. Gui Yu Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(33):8275-8282
A series of novel asymmetrical fused compounds containing the backbone of fluorene[2,3‐b]benzo[d]thiophene (FBT) were effectively synthesized and fully characterized. Single‐crystal X‐ray studies demonstrated that the length of the substituent side chains greatly affects the solid‐state packing of the obtained fused compounds. DFT, photophysical, and electrochemical studies all showed that the FBTs have large band gaps, low‐lying HOMO energy levels, and therefore good stability toward oxidation. Moreover, the substituents strongly influence the fluorescence properties of the resulting FBT derivatives. The di‐n‐hexyl compound exhibits intense fluorescence in solution with the highest quantum yield of up to 91 %. Solution‐processed green phosphorescent organic light‐emitting diodes with the di‐n‐butyl derivative as the host material exhibited a maximum brightness of 14 185 cd m?2 and a luminescence efficiency of 12 cd A?1. 相似文献
19.
K. J. Thomas K. George Thomas T. K. Manojkumar Suresh Das M. V. George 《Journal of Chemical Sciences》1994,106(6):1375-1382
A cyanine chromoionophore1 has been synthesised and its photophysical properties have been investigated. Complexation with alkali metal cations (Li+ and Na+) brings about a significant shift in the absorption and emission spectra to shorter wavelengths, which is accompanied by
an enhancement in the fluorescence quantum yield. These effects can be attributed to the suppression of intramolecular charge
transfer processes of the cyanine dye, brought about by complexation with the metal cations.
Dedicated to Professor C N R Rao on his sixtieth birthday
Contribution No. RRLT-PRU-42 from the Regional Research Laboratory, Trivandrum 相似文献
20.
Wenjiang Zhaxi Miao Li Jing Wu Luying Liu Zetao Huang Huixian Miao Xiao Ma Shenlong Jiang Qun Zhang Wei Huang Dayu Wu 《Molecules (Basel, Switzerland)》2022,27(14)
Solid-state lighting technology, where light-emitting diodes (LEDs) are used for energy conversion from electricity to light, is considered a next-generation lighting technology. One of the significant challenges in the field is the synthesis of high-efficiency phosphors for designing phosphor-converted white LEDs under high flux operating currents. Here, we reported the synthesis, structure, and photophysical properties of a tetranuclear Cu(I)–halide cluster phosphor, [bppmCu2I2]2 (bppm = bisdiphenylphosphinemethane), for the fabrication of high-performance white LEDs. The PL investigations demonstrated that the red emission exhibits a near-unity photoluminescence quantum yield at room temperature and unusual spectral broadening with increasing temperature in the crystalline state. Considering the excellent photophysical properties, the crystalline sample of [bppmCu2I2]2 was successfully applied for the fabrication of phosphor-converted white LEDs. The prototype white LED device exhibited a continuous rise in brightness in the range of a high bias current (100–1000 mA) with CRI as high as 84 and CCT of 5828 K, implying great potential for high-quality white LEDs. 相似文献