- Deciphering the evolution of supramolecular nanofibers in solution and solid-state: a combined microscopic and spectroscopic approach
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Supramolecular self-assembly of small organic molecules has emerged as a powerful tool to construct well-defined micro- and nanoarchitecture through fine-tuning a range of intermolecular interactions. The size, shape, and optical properties of these nanostructures largely depend on the specific assembly of the molecular building units, temperature and polarity of the medium, and external stimuli. The engineering of supramolecular self-assembled nanostructures with morphology-dependent tunable emission is in high demand due to the promising scope in nanodevices and molecular machines. However, probing the evolution of molecular aggregates from the solution and directing the self-assembly process in a pre-defined fashion are challenging. In the present study, we have deciphered the sequential evolution of supramolecular nanofibers from solution to spherical and oblong-shaped nanoparticles through the variation of solvent polarity, tuning the hydrophobic-hydrophilic interactions. An intriguing case of molecular self-assembly has been elucidated employing a newly designed π-conjugated thiophene derivative (TPAn) through a combination of steady-state absorption, emission measurements, fluorescence correlation spectroscopy (FCS), and electron microscopy. The FCS analysis and microscopy results revealed that the small-sized nanofibers in the dispersion further agglomerated upon solvent evaporation, resulting in a network of nanofibers. Stimuli-responsive reversible interconversion between a network of nanofibers and spherical nanoaggregates was probed both in dispersion and solvent-evaporated state. The evolution of organic nanofibers and a subtle control over the self-assembly process demonstrated in the current investigation provide a general paradigm to correlate the size, shape, and emission properties of fluorescent molecular aggregates in complex heterogeneous media, including a human cell.
- Kundu, Subhankar,Chowdhury, Arkaprava,Nandi, Somen,Bhattacharyya, Kankan,Patra, Abhijit
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- Regulation of dithiafulvene-based molecular shape and aggregation on TiO2 for high efficiency dye-sensitized solar cells
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A well-matched relationship between the molecular shape and aggregation of donor-π-acceptor (D-π-A) organic dyes is of great significance for realizing the principle of maximizing the performance of dye-sensitized solar cells (DSCs). To this end, two dithiafulvene-based organic sensitizers with different molecular shapes were synthesized, and the influence of their aggregation on TiO2 on the various performance parameters of DSCs was investigated. It was found that V-shaped DTF-C5, with a larger flare angle of 150.6° between the donor and acceptor units in the molecular structure, tended to form compact aggregates on the surface of TiO2 without the loss of adsorbed dyes, thus giving a higher short-circuit density (Jsc) of 14.92 mA cm?2 and a power conversion efficiency (PCE) of 7.39%; these values were 1.48 and 1.53 times higher than those of a DSC with a CDCA co-adsorbent, respectively. On the other hand, DTF-C6, possessing a typical V-shaped conformation with a flare angle of 120.6°, needed to co-adsorb with CDCA to fill the vacant sites between the dye aggregates on the TiO2 surface, with the aim of reducing current loss and suppressing electron recombination. Compared to a DSC with pristine DTF-C6 aggregation, an example based on the co-adsorbed system dramatically raised the PCE from 5.50% to 9.04%, owing to the improved Jsc and open-circuit voltage values. This work presents a perspective for the rational regulation of molecular shapes and the dye aggregation of organic dyes for highly efficient DSCs.
- Wu, Yuezhen,Zhang, Quande,Li, Jie,Tian, Xia,Li, Da,Lu, Xiaoqing,Xu, Bingshe,Wu, Yucheng,Guo, Kunpeng
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- Achieving red/near-infrared mechanoresponsive luminescence turn-on: mechanically disturbed metastable nanostructures in organic solids
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Two slightly twisted A-π-D-π-A molecules were prepared to demonstrate that the red/near-infrared mechanoresponsive luminescence turn-on behaviors could be realized through mechanically disturbing their weakly/non-emissive metastable nanostructures, giving
- Guo, Kunpeng,Zhang, Fang,Guo, Song,Li, Ke,Lu, Xiaoqing,Li, Jie,Wang, Hua,Cheng, Jun,Zhao, Qiang
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- The synthesis of 2,5-bis(4-amidinophenyl)thiophene derivatives providing submicromolar-range inhibition of the botulinum neurotoxin serotype A metalloprotease
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Botulinum neurotoxins (BoNTs), composed of a family of seven serotypes (categorized A-G), are the deadliest of known biological toxins. The activity of the metalloprotease, light chain (LC) component of the toxins is responsible for causing the life-threatening paralysis associated with the disease botulism. Herein we report significantly more potent analogs of novel, lead BoNT serotype A LC inhibitor 2,5-bis(4-amidinophenyl)thiophene (Ki = 10.88 μM ± 0.90 μM). Specifically, synthetic modifications involved simultaneously replacing the lead inhibitor's terminal bis-amidines with secondary amines and the systematic tethering of 4-amino-7-chloroquinoline substituents to provide derivatives with Ki values ranging from 0.302 μM (±0.03 μM) to 0.889 μM (±0.11 μM).
- Opsenica, Igor,Filipovic, Vuk,Nuss, Jon E.,Gomba, Laura M.,Opsenica, Dejan,Burnett, James C.,Gussio, Rick,Solaja, Bogdan A.,Bavari, Sina
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- Alkyl-substituted bis(4-((9H-fluoren-9-ylidene)methyl)phenyl)thiophenes: weakening of intermolecular interactions and additive-assisted crystallization
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Aggregation-induced emission (AIE) materials find their applications in organic optoelectronics, bio-imaging and sensors. In this work, we introduced alkyl substituents in AIE-active bis(4-((9H-fluoren-9-ylidene)methyl)phenyl)thiophene and elucidated thei
- Sonina, Alina A.,Becker, Christina S.,Kuimov, Anatoly D.,Shundrina, Inna K.,Komarov, Vladislav Yu.,Kazantsev, Maxim S.
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- Barbituric acid derivative of disubstituted thiophene and preparation method thereof
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The invention discloses a barbituric acid derivative of disubstituted thiophene and a preparation method thereof. The chemical structural formula of the barbituric acid derivative is as shown in the description. According to the invention, the thiophene-b
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Paragraph 0043; 0044
(2018/09/20)
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- Synthesis and evaluation of thiophene-based guanylhydrazones (iminoguanidines) efficient against panel of voriconazole-resistant fungal isolates
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A series of new thiophene-based guanylhydrazones (iminoguanidines) were synthesized in high yields using a straightforward two-step procedure. The antifungal activity of compounds was evaluated against a wide range of medicaly important fungal strains inc
- Ajda?i?, Vladimir,Senerovic, Lidija,Vrani?, Marija,Pekmezovic, Marina,Arsic-Arsnijevic, Valentina,Veselinovic, Aleksandar,Veselinovic, Jovana,?olaja, Bogdan A.,Nikodinovic-Runic, Jasmina,Opsenica, Igor M.
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p. 1277 - 1291
(2016/03/01)
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- Dithiafulvenyl unit as a new donor for high-efficiency dye-sensitized solar cells: Synthesis and demonstration of a family of metal-free organic sensitizers
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This work identifies the dithiafulvenyl unit as an excellent electron donor for constructing D-π-A-type metal-free organic sensitizers of dye-sensitized solar cells (DSCs). Synthesized and tested are three sensitizers all with this donor and a cyanoacrylic acid acceptor but differing in the phenyl (DTF-C1), biphenyl (DTF-C2), and phenyl-thiopheneyl-phenyl π-bridges (DTF-C3). Devices based on these dyes exhibit a dramatically improved performance with the increasing π-bridge length, culminating with DTF-C3 in η = 8.29% under standard global AM 1.5 illumination.
- Guo, Kunpeng,Yan, Keyou,Lu, Xiaoqing,Qiu, Yongcai,Liu, Zhike,Sun, Jianwei,Yan, Feng,Guo, Wenyue,Yang, Shihe
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supporting information; experimental part
p. 2214 - 2217
(2012/06/30)
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- Synthesis of thiophenophanes with ethyne and ethene spacers
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Synthesis of thiophenophanes with ethyne and ethene spacers has been achieved by O-alkylation, Glaser-Eglinton and McMurry coupling techniques.
- Rajakumar, Perumal,Visalakshi, Kathiresan
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experimental part
p. 213 - 220
(2011/12/05)
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