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Ratiometric fluorescent probe based on pyrrole-modified rhodamine 6G hydrazone for the imaging of Cu2+ in lysosomes
摘要： A novel rhodamine-based Schiff base derivative was obtained via the simple condensation of substituted formyl-1H-pyrrole and rhodamine 6G hydrazone. Fluorescence resonance energy transfer enabled the subsequent use of the derivative as a naked-eye colorimetric and ratiometric fluorescent sensor for Cu2+ in semi-aqueous solution, and the existence of the morpholine group enabled the further application of the sensor in imaging Cu2+ in the lysosomes of HeLa cells.
关键词： ratiometric fluorescent probe,lysosome-targeting,rhodamine hydrazone,Cu2+,FRET,pyrrole
更新于2025-09-23 15:23:52
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Domino Reaction for the Sustainable Functionalization of Few-Layer Graphene
摘要： The mechanism for the functionalization of graphene layers with pyrrole compounds was investigated. Liquid 1,2,5-trimethylpyrrole (TMP) was heated in air in the presence of a high surface area nanosized graphite (HSAG), at temperatures between 80 °C and 180 °C. After the thermal treatments solid and liquid samples, separated by centrifugation, were analysed by means of Raman, Fourier Transform Infrared (FT-IR) spectroscopy, X-Rays Photoelectron Spectroscopy (XPS) and 1H-Nuclear Magnetic Resonance (1H NMR) spectroscopy and High Resolution Transmission Electron Microscopy (HRTEM). FT-IR spectra were interpreted with the support of Density Functional Theory (DFT) quantum chemical modelling. Raman findings suggested that the bulk structure of HSAG remained substantially unaltered, without intercalation products. FT-IR and XPS spectra showed the presence of oxidized TMP derivatives on the solid adducts, in a much larger amount than in the liquid. For thermal treatments at T ≥ 150 °C, IR spectral features revealed not only the presence of oxidized products but also the reaction of intra-annular double bond of TMP with HSAG. XPS spectroscopy showed the increase of the ratio between C(sp2)N bonds involved in the aromatic system and C(sp3)N bonds, resulting from reaction of the pyrrole moiety, observed while increasing the temperature from 130 °C to 180 °C. All these findings, supported by modeling, led to hypothesize a cascade reaction involving a carbocatalyzed oxidation of the pyrrole compound followed by Diels-Alder cycloaddition. Graphene layers play a twofold role: at the early stages of the reaction, they behave as a catalyst for the oxidation of TMP and then they become the substrate for the cycloaddition reaction. Such sustainable functionalization, which does not produce by-products, allows us to use the pyrrole compounds for decorating sp2 carbon allotropes without altering their bulk structure and smooths the path for their wider application.
关键词： infrared spectroscopy,Density Functional Theory,pyrrole compounds,quantum chemical modelling,graphene layers,Functional Groups
更新于2025-09-23 15:23:52
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Synthesis and the effect of alkyl chain length on photochromic properties of diarylethene derivatives
摘要： A new class of photochromic diarylethenes bearing pyrrole and thiophene units with different length of alkyl chains at 2-position of thiophene rings have been synthesized. Their characteristics, including photochromism and fatigue resistance were investigated systematically, and each diarylethene derivative showed good photochromic properties whether in solution or in PMMA films. The alkyl group moiety was connected directly to the central cyclopentene ring as a heteroaryl unit and availably participated in photoisomerization reaction. And some properties, for example, the conversion ratio in the photostationary state(PSS) and the absorption coefficient of the ring-closed isomers in acetonitrile were significantly affected by the alkyl chain length. The results revealed that substituents of alkyl chain played an important role in the photoisomerization process of diarylethenes.
关键词： alkyl chain length,photochromism,pyrrole and thiophene units.,diarylethene
更新于2025-09-23 15:23:52
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Spectroscopy for contemporary art: Discovering the effect of synthetic organic pigments on UVB degradation of acrylic binder
摘要： The influence of Synthetic Organic Pigments in the degradation of Acrylem AC 33, a waterborne acrylic binder, after UVB-artificial exposure was furtherly investigated, extending the study to other pigments classes (anthraquinones, phthalocyanines, diketo-pyrrolo-pyrroles) in addition to previously studied azo-pigments. Together with Fourier Transform Infrared, both in Attenuated Reflectance and Transmission mode, and Nuclear Magnetic Resonance spectroscopies, Raman spectroscopy was also used to observe ageing processes that pigments are subjected to. Specific effects, relative to the presence of different pigments, have been observed also in this study; moreover, Raman spectroscopy highlighted photoinduced effects on some pigments, which could result useful in Cultural Heritage diagnostics, especially for street artworks.
关键词： diketo-pyrrolo-pyrrole,photodegradation,phthalocyanine,acrylic,anthraquinone
更新于2025-09-23 15:21:21
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Precisely Tuning Photothermal and Photodynamic Effects of Polymeric Nanoparticles by Controlled Copolymerization
摘要： In the past decades, cancer has become a major threat to the health of human being. Comparing to the conventional cancer therapy methods, such as surgery, chemotherapy, radiotherapy, and electrotherapy, photothermal and photodynamic therapy has attracted considerable interest because of their noninvasiveness, effectiveness, and negligible side effects. Photothermal therapy (PTT) can induce hyperthermia in tumor sites locally and ablate the tumor using the heat from photothermal nano-agents irradiated by the near-infrared (NIR) laser. However, hyperthermia can cause overexpression of heat shock proteins (HSPs), leading to inadequate apoptosis and tumor recurrence, thereby weakening the PTT effect. Thus, strong PTT-only nano-agents may not be the optimal choice for cancer therapy. Photodynamic therapy (PDT) can induce apoptosis and necrosis of tumor cells, mainly relying on highly toxic singlet oxygen (1O2) generated from photosensitizing nano-agents upon NIR laser irradiation. Under normoxic tumor sites, 1O2 can destroy cells and blood vessels to damage the tumor. Thus, nano-agents with moderate photothermal effect and strong photodynamic effect may be the optimal choice for killing cells and blood vessels under these sites. On the other side, the hypoxia microenvironment also formed inside the dense tumor, which limits the effect of PDT. When PDT was combined with PTT, the high hyperthermia can increase the oxygen content in a microvessel inside the dense tumor to ease the tumor hypoxic situation, which is beneficial to the PDT efficiency. Therefore, a phototherapy nanoplatform with strong photothermal and photodynamic effects may be the optimal solution to erase cancer cells inside the hypoxic dense tumor. Obviously, different conditions need different nano-agents with different functions, which requires precisely tuning of photothermal and photodynamic effects.
关键词： polymeric nanoparticles,photothermal/photodynamic effect,copolymerization,tellurium,pyrrole
更新于2025-09-23 15:21:01
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Precisely Tuning Photothermal and Photodynamic Effects of Polymeric Nanoparticles by Controlled Copolymerization
摘要： In the past decades, cancer has become a major threat to the health of human being. Comparing to the conventional cancer therapy methods, such as surgery, chemotherapy, radiotherapy, and electrotherapy, photothermal and photodynamic therapy has attracted considerable interest because of their noninvasiveness, effectiveness, and negligible side effects. Photothermal therapy (PTT) can induce hyperthermia in tumor sites locally and ablate the tumor using the heat from photothermal nano-agents irradiated by the near-infrared (NIR) laser. However, hyperthermia can cause overexpression of heat shock proteins (HSPs), leading to inadequate apoptosis and tumor recurrence, thereby weakening the PTT effect. Thus, strong PTT-only nano-agents may not be the optimal choice for cancer therapy. Photodynamic therapy (PDT) can induce apoptosis and necrosis of tumor cells, mainly relying on highly toxic singlet oxygen (1O2) generated from photosensitizing nano-agents upon NIR laser irradiation. Under normoxic tumor sites, 1O2 can destroy cells and blood vessels to damage the tumor. Thus, nano-agents with moderate photothermal effect and strong photodynamic effect may be the optimal choice for killing cells and blood vessels under these sites. On the other side, the hypoxia microenvironment also formed inside the dense tumor, which limits the effect of PDT. When PDT was combined with PTT, the high hyperthermia can increase the oxygen content in a microvessel inside the dense tumor to ease the tumor hypoxic situation, which is beneficial to the PDT efficiency. Therefore, a phototherapy nanoplatform with strong photothermal and photodynamic effects may be the optimal solution to erase cancer cells inside the hypoxic dense tumor. Obviously, different conditions need different nano-agents with different functions, which requires precisely tuning of photothermal and photodynamic effects.
关键词： polymeric nanoparticles,photothermal/photodynamic effect,copolymerization,tellurium,pyrrole
更新于2025-09-23 15:21:01
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Diversity-Oriented Synthesis and Optical Properties of Bichromophoric Pyrrole-Fluorophore Conjugates
摘要： The mild reaction conditions of the palladium-copper coupling-isomerization reaction open a highly convergent, chromogenic route to blue emissive pyrroles in the sense of a consecutive four-component reaction. By virtue of this strategy a phenol derivative can be readily accessed, which can be transformed in a level-2 transformation to a library of bichromophoric pyrrol-fluorophore conjugates by facile alkylation with fluorophore halides. The photophysics of the underlying blue emitter derivative and the conjugates is studied by absorption and emission spectroscopy, furnishing intramolecular energy transfer at short distances as well as competing fluorescence quenching. In some cases partial energy transfer results in the occurrence of dual emission, for instance seen as magenta-rose emission arising from blue and red orange luminescence. The experimental photophysical studies are rationalized by DFT and TD-DFT calculations.
关键词： DFT,multicomponent reaction,energy transfer,level-2 functionalization,absorption,emission,bichromophores,pyrrole
更新于2025-09-19 17:15:36
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IR Cavity Ringdown Spectroscopy and Density Functional Theory for Jet-Cooled Pyrrolea??Cyclopentanone Binary Clusters: Effect of Pseudorotation on Na??H?·?·?·Oa??C Hydrogen Bonds
摘要： The geometry and energetics of the N-H…O=C hydrogen bond (H-bond) are important to understand the stability and flexibility of biomolecules, such as protein and DNA. Jet-cooled pyrrole-cyclopentanone (Py-Cp) binary clusters are appropriate models to investigate the N-H…O=C H-bond from a microscopic point of view. In this study, NH stretching vibrations of the Py-Cp binary clusters were observed by IR cavity ringdown spectroscopy. Furthermore, density functional theory calculations revealed geometric structures, harmonic vibrations, intermolecular energies, and donor-acceptor interactions for various sizes of binary clusters. The IR spectra of the Py-Cp binary clusters were measured under various conditions of the vapor pressures of Py and Cp in He buffer gas for a supersonic expansion. The dependence of the IR band intensities on the vapor pressure provides vibrational assignments of the NH stretching vibrations, which were reproduced by calculated frequencies of Py1-Cp1, Py1-Cp2, and Py2-Cp1. An admixture of Ar in He buffer gas for a supersonic expansion was also applied to produce Py1-Cp2 in order to differentiate several NH stretches of isomeric structures due to the pseudorotation of Cp molecules. Py1-Cp1 is formed by the N-H…O=C H-bond. Py1-Cp2 has a cyclic structure that is formed by the N-H…O=C H-bond and stacking interactions among Py and two Cp molecules. Py2-Cp1 also has a cyclic structure that is formed by not only the N-H…O=C H-bond, but also a N-H…π H-bond between two Py molecules and a stacking interaction between Py and Cp. A comparison of the H-bond geometries between Py2-Cp1 and the corresponding pyrrole-acetone binary cluster reveals that the stacking interaction between Py and Cp strengthens the N-H…O=C and N-H…π H-bonds through a cooperative effect.
关键词： Density Functional Theory,Cyclopentanone,Spectroscopy,Quantum Chemistry,Pyrrole,IR Cavity Ringdown Spectroscopy,Hydrogen Bonds,Molecular Structure,Pseudorotation
更新于2025-09-19 17:13:59
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An electron donating controlling strategy for design several dithieno[3,2-b:2′,3′-d]pyrrole based dyes with D–D–A structure in dye-sensitized solar cells
摘要： One of the important strategies for designing pure organic dyes is to improve the electron donating abilities of dye donors hence increase the intramolecular potential energy difference. In order to quantify the electron-donating capacity of organic units, we firstly propose a parameter donation ability (DA) value for evaluating the electron DA of organic units via theoretical calculation, by using of several fragments such as coplanar dithiophenyl pyrrole, triphenylamine (TPA), phenothiazine (PTZ) and cyanoacetic acid (CA) which is the research objects here. Inspired by the DA values of the above organic fragments, dye PSD-9, PSA-10 and PST-11 were designed and synthesized. Cyclic voltammetric (CV) measurements show that the DA values of dye PSA-10 and PST-11’s donor increases when TPA and PTZ groups are introduced into PSD-9, hence HOMO level increases and the band-gap narrow down. This change is reflected in the absorption spectra: the maximum absorption wavelength of PSA-10 and PST-11 is 63 and 84 nm red-shifted compared with PSD-9. Similarly, the molar extinction coefficients of PSA-10 and PST-11 are increased by 34.7 × 103 and 14.7 × 103 M?1 cm?1, respectively. Combining a mesoporous titania film grafted by these dithiophenyl pyrrole dye with iodine electrolyte, an 4.2% and 4.8% power conversion effciency (PCE) is achieved for PSA-10 and PST-11 at an irradiance of the AM1.5G sunlight, with an significant increasing compared to PSD-9 with an PCE of 1.6%. The typical photocurrent density–voltage (J–V) test shows that the short circuit current of dye PSA-10 and PST-11 is much higher than that of PSD-9, which is the main reason for the improvement of PCE. The red-shift and stronger IPCE curve is the most advantageous evidence of the change of short circuit current. Furthermore, electrochemical impedance measurements is studied for exploring the changes of open-circuit voltage of PSA-10 and PST-11, the results infer that larger donor units and long alkyl chains can effectively increasing current density on photoanode, hence increase the open circuit voltage of the devices.
关键词： electron donating ability,dithieno[3,2-b:2′,3′-d]pyrrole,dye-sensitized solar cells,organic dyes,power conversion efficiency
更新于2025-09-12 10:27:22
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Synthesis and characterization of poly(pyrrole- <i>co</i> -2-nitrocinnamaldehyde) (PPNC), a new copolymer for solar cells applications
摘要： The use of conductive polymers as a substitute for metallic conductors and semiconductors has attracted much attention in the literature. In particular, aromatic heterocyclic polymers constitute an important class since they possess chemical and electrical stability in both the oxidized (doped) and neutral (undoped) state. A series of poly(pyrrole-co-2-nitrocinnamaldehyde) were obtained via the condensation of pyrrole and 2-nitrocinnamaldehyde in chloroform using acid exchanged montmorillonite clay called maghnite-Ht as an efficient catalyst. The conjugated copolymer was characterized using proton nuclear magnetic resonance, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy.
关键词： solubility,Copolymer synthesis,poly(pyrrole-co-2-nitrocinnamaldehyde),pyrrole,2-nitrocinnamaldehyde
更新于2025-09-11 14:15:04