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81.
Kristina Ilina Dr. Maged Henary 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(13):4230-4248
Cyanine dyes carrying quinoline moieties are an important class of organic molecules that are of great interest for applications in many fields like medicine, pharmacology, and engineering. Despite their exceptional properties, such as stability, high molar extinction coefficients, and high pH-sensitivity, this class of dyes has been less analyzed and reviewed in the last few decades. Therefore, this review article focuses on discussing the history of quinoline compounds, various synthetic routes to prepare quinolinium salts and symmetrical and asymmetrical mono-, di-, tri-, penta- and heptamethine cyanine dyes, containing quinoline moieties, together with their optical properties and applications as photosensitizers in photodynamic therapy, probes in biomolecules for labeling of nucleic acids, as well as imaging agents. 相似文献
82.
Manon Catherin Olatz Uranga-Barandiaran Arnaud Brosseau Dr. Rémi Métivier Dr. Gabriel Canard Dr. Anthony D'Aléo Dr. David Casanova Prof. Frédéric Castet Dr. Elena Zaborova Prof. Frédéric Fages 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(17):3818-3828
We describe the synthesis of a series of covalently linked dimers of quadrupolar curcuminoid-BF2 dyes and the detailed investigation of their solvent-dependent spectroscopic and photophysical properties. In solvents of low polarity, intramolecular folding induces the formation of aggregated chromophores, the UV/Vis absorption spectra of which display the optical signature characteristic of weakly-coupled H-aggregates. The extent of folding and, in turn, of ground-state aggregation is strongly dependent on the nature of the flexible linker. Steady-state and time-resolved fluorescence emission spectroscopies show that the Frenkel exciton relaxes into a fluorescent symmetrical excimer state with a long lifetime. Furthermore, our in-depth studies show that a weakly emitting excimer lies on the pathway toward a photocyclomer. Two-dimensional 1H NMR spectroscopy and density functional theory (DFT) allowed the structure of the photoproduct to be established. To our knowledge, this represents the first example of a [2π+2π] photodimerization of the curcuminoid chromophore. 相似文献
83.
Dr. Eva Kirchner Dr. David Bialas Prof. Frank Würthner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11294-11301
Exciton coupling between different types of chromophores has been rarely investigated. Herein, a systematic study on the exciton coupling between merocyanine chromophores of different conjugation length with varying excited state energies is presented. In this work well-defined hetero-dimer stacks were obtained upon folding of bis(merocyanine) dyes in nonpolar solvents. They show distinctly different absorption properties in comparison with the spectra of the single chromophores, revealing a significant coupling between the different chromophores. The simulated absorption spectra obtained from time-dependent density functional theory (TD-DFT) calculations are in good agreement with the experimental spectra. Our theoretical analysis based on an extension of Kasha's exciton theory discloses strong coupling between the dyes’ transition dipole moments despite of an excited-state energy difference of 0.60 eV between the chromophores. 相似文献
84.
85.
Dmitri V. Konarev Aleksey V. Kuzmin Salavat S. Khasanov Alexander F. Shestakov Akihiro Otsuka Hideki Yamochi Hiroshi Kitagawa Rimma N. Lyubovskaya 《化学:亚洲杂志》2020,15(17):2689-2695
Two salts of the aromatic hydrocarbon decacyclene, {cryptand[2.2.2](Cs+)} (decacyclene.?) ( 1 ) and {Bu3MeP+}(decacyclene.?) ( 2 ), were obtained. In both salts, decacyclene.? radical anions formed channels occupied by cations. However, corrugated hexagonal decacyclene.? layers could be outlined in the crystal structure of 1 with several side‐by‐side C???C approaches. The decacyclene.? radical anions showed strong distortion in both salts, deviating from the C3 symmetry owing to the repulsion of closely arranged hydrogen atoms and the Jahn‐Teller effect. Radical anions showed intense unusually low energy absorption in the IR‐range, with maxima at 4800 and 6000 cm?1. According to the carculations, these bands can originate from the SOMO‐LUMO+1 and SOMO‐LUMO+2 transitions, respectively. Radical anions exhibited a S=1/2 spin state, with an effective magnetic moment of 1.72 μB at 300 K. The decacyclene.? spin antiferromagnetically coupled with a Weiss temperature of ?11 K. Spin ordering was not observed down to 1.9 K owing to spin frustration in the hexagonal decacyclene.? layers. 相似文献
86.
Sarah R. Geenen Lysander Presser Dr. Torsten Hölzel Prof. Dr. Christian Ganter Prof. Dr. Thomas J. J. Müller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(36):8064-8075
Differently 5-substituted 8-methoxypsoralens can be synthesized by an efficient synthetic route with various cross-coupling methodologies, such as Suzuki, Sonogashira and Heck reaction. Compared to previously synthesized psoralens, thereby promising daylight absorbing compounds as potentially active agents against certain skin diseases can be readily accessed. Extensive investigations of all synthesized psoralen derivatives reveal fluorescence in the solid state as well as several distinctly emissive derivatives in solution. Donor-substituted psoralens exhibit remarkable photophysical properties, such as high fluorescence quantum yields and pronounced emission solvatochromicity and acidochromicity, which were scrutinized by Lippert–Mataga and Stern–Volmer plots. The results indicate that the compounds exceed the limit of visible light, a significant factor for potential applications as an active agent. In addition, (TD)DFT calculations were performed to elucidate the underlying electronic structure and to assign experimentally obtained data. 相似文献
87.
An ultrasound-assisted nanoscaled supramolecular coordination polymer (nanosized 1′ ) has been synthesized using a self-assembly reaction of K3[Cu (CN)4] and hexamethylenetetramine in the presence of Me3SnCl under ambient conditions. Nanosized 1′ was examined using elemental analysis, Fourier transform–infrared, transmission electron microscopy, scanning electron microscopy and X-ray powder diffractions. It was structurally compared with the single crystal supramolecular coordination polymer ∞3[Cu6(CN)7(C6H12N4)2(OH3)]; SCP 1. The photocatalytic activities of nanosized 1′ and SCP 1 toward different hazardous organic dyes were determined under ambient, UV-light irradiation and ultrasonic conditions. SCP 1 and nanosized 1′ as heterogeneous nanoparticles catalysts exhibited high catalytic activity for degradation of Congo Red, Methyl Violet 2B and Methylene Blue dyes. The effects of operational parameters on catalytic degradation process, identification of the degradation products and recycling of the catalyst were also investigated. SCP 1 and nanosized 1′ are recyclable heterogeneous catalysts and can be reused with efficient activities. The mechanism of degradation using different scavenger techniques iss proposed and discussed. The catalytic oxidation process is mainly caused by •OH radicals. 相似文献
88.
Dr. Boris Schade Dr. Abhishek Kumar Singh Dr. Virginia Wycisk Dr. Jose Luis Cuellar-Camacho Dr. Hans von Berlepsch Prof. Rainer Haag Dr. Christoph Böttcher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(30):6919-6934
The syntheses of novel amphiphilic 5,5′,6,6′-tetrachlorobenzimidacarbocyanine (TBC) dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. For the achiral meso form, a new synthetic route towards asymmetric cyanine dyes was established. All compounds form J aggregates in water, the optical properties of which were characterised by means of spectroscopic methods. The supramolecular structure of the aggregates is investigated by means of cryo-transmission electron microscopy, cryo-electron tomography and AFM, revealing extended sheet-like aggregates for chiral enantiomers and nanotubes for the mesomer, respectively, whereas the conformer forms predominately needle-like crystals. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry, which in the case of enantiomers enables the formation of extended hydrogen-bond chains by the hydroxyl functionalities. In case of the achiral meso form, however, such chains turned out to be sterically excluded. 相似文献
89.
Dr. Aron J. Huckaba Dr. Aswani Yella Dr. Louis E. McNamara April E. Steen J. Scott Murphy Casey A. Carpenter George D. Puneky Prof. Nathan I. Hammer Prof. Mohammad Khaja Nazeeruddin Prof. Michael Grätzel Prof. Jared H. Delcamp 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15536-15542
Desirable components for dye‐sensitzed solar cell (DSC) sensitizers and fluorescent imaging dyes include strong donating building blocks coupled with well‐balanced acceptor functionalities for absorption beyond the visible range. We have evaluated the effects of increasing acceptor strengths and incorporation of dye morphology controlling groups on molar absorptivity and absorption breadth with indolizine donor‐based dyes. Indolizine‐based D –A and D –π–A sensitizers incorporating bis‐rhodanine, tricyanofuran (TCF), and cyanoacrylic acid functionalities were analyzed for performance in DSC devices. The TCF derivatives were also evaluated as near‐infrared (NIR)‐emissive materials with the AH25 emissions extending past 1000 nm. 相似文献
90.
《Comptes Rendus Chimie》2016,19(3):371-380
Manganese porphyrin has been supported onto multi-walled carbon nanotubes (Mn(TCPP)OAc@MWCNT) and characterized by powder X-ray diffraction, FT-IR, atomic absorption and UV–vis spectroscopy, field emission scanning electron microscopy (FE-SEM) and also thermogravimetric analysis (TGA). The TGA curve shows that the nanocatalyst was thermally stable up to almost 350 °C. This catalyst was found to be able to oxidize different synthetic textile dyes in aqueous media over a wide pH range at ambient temperature with tert-butyl hydroperoxide (TBHP) as the oxygen source. The influence of some important parameters such as the initial pH of the dye solution, temperature and concentration of the catalyst, the oxidant and the co-catalyst were investigated. Also, the ability of this heterogeneous catalyst to oxidize 2,6-dimethylphenol (with excellent selectivity for quinone (86%)) with TBHP in acetonitrile was evaluated. The separation and recycling of the catalyst is simple and the catalyst can be used several successive cycles without significant decrease in catalytic activity. 相似文献