ChemPhotoChem最新文献

We present Transient Absorption Processing and Analysis Software (TAPAS), an open-source, Python-based graphical platform that covers the entire transient absorption (TA) workflow, from raw data import and preprocessing to visualization, global and target fitting, and statistical evaluation. Users operate TAPAS through an intuitive, seven-tab GUI, yet all underlying modules remain accessible for inspection and extension, merging GUI convenience with script-level flexibility. The fitting engine employs just-in-time compilation via an open-source machine learning compiler ecosystem, delivering two–20-fold speed gains over established packages. Automatic differentiation and residual-based effective-sample-size calculations yield reliable confidence intervals and correlation matrices, while an integrated sampling routine provides full Bayesian posterior exploration—diagnostics which are rarely available in other TA tools. All raw, processed, and fitted data are written to standardized Hierarchical Data Format 5 containers and automatically annotated with rich metadata, ensuring complete provenance. An extended case study on Rose Bengal shows how TAPAS first reveals hidden lifetime correlations, then employs broadband global and target analysis to merge TA traces with complementary steady-state and literature data, yielding a single, self-consistent kinetic model. By uniting advanced uncertainty quantification and transparent data management within a user-friendly interface, TAPAS closes the gap between accessibility and rigorous statistical treatment in TA spectroscopy.

The Front Cover illustrates the concept of the “ESIPT machine,” symbolizing the synthesis of N-substituted imidazoles via the Debus–Radziszewski reaction. The assembly line represents the multi-component process leading to molecules that could exhibit a tunable solvent-dependent excited-state intramolecular proton transfer (ESIPT) process. More information can be found in the Research Article by J. L. Belmonte-Vázquez and co-workers (DOI: 10.1002/cptc.202500262). Illustration by Armando Navarro-Huerta.

The Cover Feature illustrates the formation of cycloaddition products through the key “distonic radical cation” intermediates that can be generated from a variety of redox active molecules. Various reagents, depicted as water bubbles, rise through the photoredox fountain, getting converted to their respective distonic radical cation forms. Subsequent reaction with suitable partners, leads to the formation of various cycloadducts represented by the water droplets emerging out of the fountain. More information can be found in the Review by S. Debnath and S. Maity (DOI: 10.1002/cptc.202500249). Art by Arunima Mukherjee.

The Front Cover illustrates the mode of action of Lyso-Naphth-AIE, a novel aggregation-induced emission (AIE) photosensitizer (PS) that specifically targets lysosomes. Upon light irradiation, Lyso-Naphth-AIE (white structure) generates reactive oxygen species (ROS, red spheres) through both type I and II photodynamic therapy (PDT) mechanisms, and this triggers apoptosis. Additionally, the near-infrared luminescence of the activated Lyso-Naphth-AIE enables real-time imaging. This work establishes a new approach for designing multifunctional AIE PSs for imaging-guided PDT. More information can be found in the Research Article by U. R. Gandra, M. I. Haja Mohideen, M. Magzoub and co-workers (DOI: 10.1002/cptc.202500202).

Converting atmospheric nitrogen (N₂) into ammonia (NH₃) by sustainable methods presents a significant challenge in green chemistry. Photocatalytic N₂ fixation under visible light offers a promising solution, provided efficient catalysts can effectively weaken the strong N≡N bond. In this study, we present a composite photocatalyst composed of the metal–organic framework (MOF) UiO-66-NH₂ and substoichiometric tungsten oxide (W₁₈O₄₉). The oxygen vacancies in W₁₈O₄₉ extend its visible light absorption, while UiO-66-NH₂ provides a high surface area and amine-functionalized linkers that enhance light harvesting. We synthesized UiO-66-NH₂/W₁₈O₄₉ composites with varying UiO-66-NH₂ contents (30%, 50%, and 70% by weight) and evaluated their photocatalytic performance under visible-light irradiation. The 50% UiO-66-NH₂/W₁₈O₄₉ composite exhibited the highest NH₃ production rate of 420.8 μmol g⁻¹ h⁻¹, which is 27.2 times higher than that of pure UiO-66-NH₂ and 10.9 times higher than that of W₁₈O₄₉. This enhancement is attributed to the synergistic heterojunction between UiO-66-NH₂ and W₁₈O₄₉, where the MOF provides a large surface area and efficient light absorption, while W₁₈O₄₉ contributes plasmon-generated hot electrons and abundant oxygen vacancies. The composite demonstrates broadened visible-light absorption, efficient charge separation, and rapid charge transfer, thus suppressing electron–hole recombination. These results highlight the potential of the UiO-66-NH₂/W₁₈O₄₉ composite as an effective photocatalyst for solar-driven ammonia production under mild conditions.

In this contribution, a set of five differently substituted phenoxazines (POA) derived from a central terephthalonitrile core is investigated. Depending on incorporated electron-donating groups (-NH₂, -NMe₂, and -OMe) or electron-withdrawing groups (-NO₂ and -CN), distinctive luminescent behavior is observed, with preferred emission either in solution, in the solid-state, or in both. An in-depth assessment of the photophysical properties revealed a subtle influence of the substituents on the absorption and emission wavelengths, which correlate with the Hammett parameters, yet a strong sensitivity to the surrounding environment. Hence, solvatochromic response and aggregation studies were conducted to identify the optimal conditions for efficient emission. Absolute photoluminescence quantum yield values of up to 0.47 in tetrachloromethane and 0.33 in the solid state were determined, underscoring the impressive photophysical characteristics of the presented compounds. X-ray diffractometric analyses in combination with Hirshfeld surface evaluation were employed to elucidate the packing effects and their possible relation to the photophysical performance. Finally, density functional theory calculations provided a detailed understanding of the occurring electronic transitions and spatial localization of the natural transition orbitals.

Metallophotoredox catalysis is very useful in transforming the chemical moieties for readily available diverse scaffolds. This study presents an efficient and concise methodology devised for decarboxylative oxidation of aliphatic carboxylic acid through manganese (II) acetate-catalyzed visible blue light-induced homolysis. The control experiments showed the presence of peroxide radical along with singlet oxygen suggesting the radical pathway. The light on/off experiment proved that continuous irradiation of light is essential for efficient photocatalytic decarboxylative oxygenation reaction. The established protocol is applicable for both primary and secondary carboxylic acids to afford aldehydes and ketones, respectively, in good yields.

This article presents an in-depth study on the use of tetrazine-based coordination polymers as photocatalysts for the treatment of wastewater contaminated with organic pollutants. The synthesis of a Zn-based MOF incorporating s-tetrazine dicarboxylic acid as an organic ligand is detailed, following a solvothermal method. Analysis of the crystalline structure reveals a three-dimensional porous network characterized by pores approximately 8 Å wide, forming a highly interconnected material. The photocatalytic activity of this material is then investigated for the degradation of ibuprofen under simulated solar irradiation. The reaction mechanism and the intermediate species involved in the degradation pathway are elucidated. This research contributes to a better understanding of tetrazine-based materials in aqueous-phase applications and highlights their potential for sustainable environmental treatment strategies.

Freshwater pollution is a critical global issue, requiring efficient, eco-friendly treatment technologies. In this study, a new ternary nanocomposite photocatalyst was fabricated by combining silver phosphate (Ag₃PO₄) with platinum nanoparticles (Pt NPs) and polymethyl methacrylate (PMMA), a flexible long-chain polymer. The nanocomposite was prepared using coprecipitation, ultrasonic blending, and light-induced reduction. Structural and chemical analyses confirmed successful integration of all components. (XRD) X-ray Diffraction verified the body-centered-cubic phase of Ag₃PO₄, while X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy evidenced the presence and interaction of Ag₃PO₄, Pt, and PMMA. (TEM) Transmission Electron Microscopy revealed PtNPs (5–15 nm) uniformly anchored to the PMMA-coated Ag₃PO₄ surface, displaying varied morphological features. Optical characterization via UV–vis spectroscopy showed a clear reduction in bandgap, enhancing visible light absorption. The Pt@PMMA/Ag₃PO₄ photocatalyst demonstrated outstanding contaminant removal under visible light, achieving 94.20% breakdown of imidacloprid (IM) insecticide in 60 min and near-total removal of acridine orange (ACO) dye in just 15 min. This enhanced performance is attributed to increased light utilization from Pt, larger reactive surface area, and efficient charge separation and transport facilitated by the polymer network, as evidenced by photocurrent response and reduced photoluminescence. The currently developed Pt@PMMA/Ag₃PO₄ nanocomposite shows strong potential as a high-performance, sustainable photocatalyst for light-driven water purification.

Metastable-state photoacid (mPAH) has become a common tool for controlling and driving chemical processes with light. mPAHs with fast reverse reactions are desirable for precise temporal control or generating quick pulses of proton concentration. In this work, different approaches towards fast reversing mPAHs are studied. Experimental and computational results showed that stabilizing the charge–transfer intermediate is an effective way to increase the rate. A novel mPAH with a reverse reaction ≈500 times faster than the most used mPAH in methanol is developed. Another water-soluble mPAH showed a reverse reaction with a rate constant of 7.8 s⁻¹, which is the fastest ever reported. The half-life of the acidic state is calculated to be 89 ms, which allowed to demonstrate sub-second switching using this mPAH.