Dyes and Pigments最新文献

The effect of solvents and substituents on the C.I. Pigment PR170, the best known member of the naphthol red family, is investigated. Both PR170 and its alkoxy derivatives were analyzed using FTIR, 1H NMR and UV–Vis spectroscopy. The study included the evaluation of the average local ionization energy (ALIE), MEP, HOMO-LUMO analysis. The nature of intra- and intermolecular contacts in the crystal structure was also investigated using crystal packing and Hirshfeld surface analysis. Covalent and non-covalent interactions in PR170 were comprehensively described by IRI, RDG and ELF. In addition, Natural Bonding Orbital (NBO) and Fukui function calculations were performed. An analysis of the UV–Vis electronic transitions for different solvents was carried out, providing insight into the charge transfer processes within both PR170 and its derivatives. In particular, the research indicated a CT-type excitation at the S2 level during the hole-electron transfer analysis. The NLO results showed that PR170 is a promising candidate for nonlinear optical materials.

In organic-inorganic perovskite solar cells (PSCs), the electron transport layer (ETL) plays a crucial role providing efficient electron extraction and transport required for achieving high device performance. Compared to traditional fullerene-based electron-transport materials (ETMs), non-fullerene small molecules have attracted much attention due to their tunable optoelectronic properties, lower cost, and much higher stability. In this work, we synthesized and characterized four perylenediimide (PDI) derivatives and investigated their optoelectronic properties in the context of application as ETMs for PSCs. To establish the compatibility of PDI films with perovskite absorber material, the surface properties of Cs_0.12FA_0.88PbI₃/PDI bilayer stacks were studied using contact angle and infrared scattering scanning near-field microscopy methods. A study of the photochemical stability of these bilayer stacks showed that coating the perovskite film with a layer of PDI improves its tolerance with respect to light. Utilizing these molecules as ETMs in the inverted p-i-n PSCs delivered light power conversion efficiencies ranging from 11.1 % to 15.4 %, thus indicating the considerable effect of the PDI derivative molecular structure on the photovoltaic properties. Further development of this research direction may lead to the rational design of advanced PDI-based electron transport materials for efficient and stable PSCs.

The dyes with light absorption ability in extended spectrum have huge potential in various photovoltaics applications. Absorption maxima (Lambda max) is predicted using machine learning (ML). Multiple machine learning models are used. Random Forest is best model among the tried ML models. A library of new dyes is created using python-based tool. Absorption maxima of newly generated dyes is predicted using best ML model (Random Forest). The generated library of dyes is visualized using Uniform Manifold Approximation and Projection (UMAP) plot. 30 dyes with absorption in extended spectrum are selected. Synthetic accessibility assessment is done to check ease of synthesis of selected dyes and to further narrow down the number of potential candidates. Structural behavior of selected dyes is studied using hierarchical cluster analysis. This study offers a theoretical framework for developing potential dyes that could exhibit light absorption in near-IR region of solar spectrum.

Curcumin has excellent anti-tumor activity, but its instability at physiological pH, low bioavailability and poor targeting limit curcumin to further become an excellent anticancer drug. In this study, two curcumin/nido-carborane fluorescent polymers, curcumin-borane-crown ether coated by sodium alginate (SA-CBC) and curcumin-borane-crown ether (CBC), were prepared, and SA-CBC with better properties to be the most promising anti-tumor drugs. Crown ether/sodium alginate drug delivery strategies can improve the release property of curcumin. Nido-carborane enhances the targeting of curcumin and the inhibiting effect on tumor cells. After testing, the fluorescence lifetime of SA-CBC was 4.72 ns, indicating good fluorescence properties. In vitro drug release results showed that the constructed drug delivery system released curcumin at a controlled rate. The results of transmission electron microscopy and particle size showed that SA-CBC was well encapsulated, with a particle size of less than 200 nm, easy to be absorbed in vivo. Bioactivity studies showed that SA-CBC had a strong affinity and inhibiting effect on tumor cells, and the inhibition rate could reach 84.5 %. In conclusion, this study provides an innovative protocol for the design of curcumin anticancer drugs and lays the foundation for the development of more effective anti-tumor drugs with small side effects.

The optical properties of four 3-amino-1,8-naphthalimide derivatives differing in the degree of substitution at the amino functionality were synthesised and studied by UV–visible absorbance and fluorescence spectroscopy in 1:1 (v/v) methanol/water and methanol. The compounds were structurally characterized by NMR, IR and HRMS. The charge transfer absorbance band was observed to shift to longer wavelength with increasing ethyl substitution. The emission band was also observed to shift to longer wavelengths with a decrease in the emission intensity with increasing ethyl substitution due to the peri effect. Irradiation of dye methanol solutions and in the solid state with a 365 nm UV lamp reveals distinct emission colours for each compound. Significantly larger Stokes shifts are observed in methanol than in mixed aqueous methanol. Quantum chemical calculations at the B3LYP/TZVP level of theory provided insight into the optimized ground state geometry, frontier molecular orbitals levels and solute-solvent dynamics revealing a stronger hydrogen bond between the 3-amino-1,8-naphthalimides and methanol in the lowest S1 excited state. The dyes were tested as fluorescent stains in MCF-7 cancer cells and observed to emit green emission in various organelles.

Electrochromic materials have been widely used in various parts of life due to their advantages of energy conservation and rich colors. In this work, a series of novel viologen derivatives (tetrasubstituted thienoviologen derivatives, a–f) were designed and synthesized as electrochromic materials by decorating 4,4′,4″,4‴-(thiophene-2,3,4,5-tetrayl)tetrapyridine with different N-substituents (alkyl, benzyl and aryl). Electrochromic devices based on a–f exhibited a low working voltage of −1.4 V. The N-substituents markedly affected their electrochromic performance. The compounds with alkyl and benzyl substituents performed better than the compound with aryl substituent. Among them, compound c with benzyl substituent performed best with a high optical contrast (66 %), a high coloration efficiency (389 cm²/C), good cycling stability, and fast response time. Besides, compound c was also applicable to sodium carboxymethyl cellulose hydrogel ECD with good cycling stability and a broad absorption band (500–700 nm) in the visible region. The applications of compound c in electronic tags, functional displays and smart windows were explored, indicating it's a promising ECM with wide application prospects.

Three novel organic fluorescent probes M1-M3 with different conjugation length have been designed and synthesized from readily available starting materials via concise procedures. The obtained carbonyl-substituted imidazopyridines M1-M3 exhibit viscosity- and polarity-dependent dual-responsive properties. Structural modulation indicates that the polarity and viscosity sensitivity of M1-M3 can be tuned by variation of conjugation length. Importantly, M1-M3 demonstrate sensing ability for 2,6-dichloro-4-nitroaniline (DCN) with high selectivity and sensitivity in THF with a limit of detection (LOD) of 189 ppb, 62 ppb, and 54 ppb, respectively. The luminescence quenching of the compounds is caused by photo-induced electron transfer.

A new (D-D’π-A) type ferrocene and methoxyphenyl (D-D′) conjugated indanedione (A) based linear and π-extended multi-donor-π-acceptor chromophores 1–4 were synthesized and characterized. The chromophores 2–4 were further investigated by single-crystal analysis through X-ray diffraction, revealing centrosymmetric space groups with non-covalent interactions (inter, intramolecular hydrogen bonding, and C–H…π interactions) and these molecular packing interactions favor SHG efficiencies. Electrochemical studies show the one-electron charge transfer (Fe²⁺⇌Fe³⁺) and observed greater redox potential of chromophore 4 than the parent ferrocene due to the substitution effect. The solvatochromic studies in emission spectra resulted in redshift (56–109 nm) for the chromophores 1–4 by increasing the solvent polarities, which indicates higher excited state stabilization relative to the ground state, results effective intramolecular charge transfer process within the chromophores. The occurrence of ferrocene moieties lowers the fluorescence intensities of the chromophores 1–4, which was overcome through aggregation induced emission enhancement (AIEE) studies at 60 % (THF/H₂O). The AIEE state also shows 23 times higher quantum yield than the THF solution for chromophore 4. In addition, a thin film using polymethyl methacrylate as a binder shows a significant blue shift with higher emission intensity than those obtained in the solution due to the intermolecular interactions and enhancement of viscosity. The SHG efficiency studied using the Kurtz and Perry powder technique results in a higher value for chromophore 4 (2 times higher than the reference KDP) attribute to the multi donors, acceptor, and extended π conjugation reducing the anti-parallel alignment in the solid state. The computational calculations were done to validate the experimental results using B3LYP/6-31+G** level of theory.

Till now, there is still a lack of the convenient and efficient approach to implement identification and quantitation of fullerenes in various domains. This work provides the first example for detecting fullerenes by an adequate fluorescent probe, in parallel with the new methodology for detecting fullerenes by the fluorescent chemosensing approach. Using a multi-emission lanthanide-disalicylaldehyde coordination hybrid H₂Q_j2/Tb_0.91Eu_0.09, the rapid, selective and discriminative detection of analogous C₆₀ and C₇₀ can be easily achieved after the spectral and statistical analyses of fluorescent sensing signals on four emission bands (416, 543, 447 and 615 nm), excited by two irradiation lights (370 and 394 nm). Titration experiments further verify the very high linearity for both C₆₀ and C₇₀ and allow their detection at concentrations as low as 1.72 μM (C₆₀) and 0.09 μM (C₇₀). Moreover, this fluorescent probe also shows its reliable abilities to identify proportional C₆₀/C₇₀ mixtures and monitor C₆₀ and C₇₀ contents in actual soil sample. It is believed that our proposed lanthanide-base fluorescent matrix not only verify the feasibility and potential of fluorescent chemosensing methodology for the fullerene detection but also provide a valuable tool for potential applications.

This paper describes the synthesis of new naphthalene diimide (NDI) derivatives obtained in good yields from the reaction between 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) and different p-alkoxy-substituted anilines. The photophysical properties of the NDIs were investigated in solution and the solid state. UV–visible absorption spectra in 1,4-dioxane, dichloromethane, and acetonitrile showed absorption maxima at approximately 375 nm, related to symmetry and spin allowed ¹π-π* electronic transitions. These compounds did not exhibit fluorescence emission in the studied solvents. Electrochemical studies have indicated that the presence of different alkyl chains significantly affects the capacity of NDIs when used as organic cathodes in Al-graphite batteries due to variations in their ability to intercalate tetrachloroaluminate. The organic cathodes incorporating NDIs with varying alkyl chain lengths exhibited distinct capacities: 123.5 mA h g⁻¹ for 3a, 101.6 mA h g⁻¹ for 3b, and 157.3 mA h g⁻¹ for 3c, with a capacity retention of approximately 54 % after 15 charge‒discharge cycles. These findings highlight the crucial role of alkyl chain modification in optimizing the electrochemical performance of organic cathodes.