ChemPhotoChem最新文献

A protocol for the synthesis of sterically hindered 9-silylacridines via lithiation/silylation sequence is developed. The photocatalytic efficiency of obtained acridines is tested in a variety of decarboxylative processes and compared with the properties of aryl- and alkyl-substituted analogs. To explain the observations, quantum chemical calculations are carried out, revealing the features of the spatial structures of these molecules.

Organic room-temperature phosphorescence (RTP) materials have vitalized exponential attention in the fields of optoelectronics, information encryption, and biological imaging due to their unique luminescent properties. Nevertheless, achieving water-resistant RTP materials remains a major challenge, primarily due to the high sensitivity of triplet excitons to water-induced quenching. In this concept, the recent advances in the development of water-resistant RTP materials, including the design principles, detailed phosphorescence properties, and their potential applications, are summarized. In addition, it presents the current challenges and future perspectives on developing organic water-resistant RTP materials. This concept is expected to offer valuable insights for the design of high-performance organic water-resistant RTP materials and pave the way toward diverse practical applications in aqueous environments.

Photocatalysis-assisted peroxymonosulfate (PMS) activation is a promising technology for the degradation of antibiotics in water remediation. Herein, MXene-derived oxide (TiO₂) and g-C₃N₅ Z-scheme ternary heterojunction photocatalytic composite materials are synthesized using an electrostatic self-assembly approach and characterized. The optimized g-C₃N₅/TiO₂/Ti₃C₂ (CNTT) heterostructure demonstrates exceptional photocatalytic activity for tetracycline (TC) removal, achieving 90% degradation within 60 min at an optimal g-C₃N₅:TiO₂/Ti₃C₂ mass ratio of 3:2. Remarkably, the system exhibits broad pH adaptability (80.8–96.3% TC removal across pH 2–12), overcoming the pH sensitivity limitations of traditional PMS-based processes. Mechanistic investigations reveal a synergistic photocatalysis-PMS activation pathway, with quenching experiments confirming $$, ·OH, ·$$, and ¹O₂, as dominant reactive species. The CNTT composite maintains 65.2% degradation efficiency after five cycles, demonstrating robust stability. Coexisting ions negatively influence TC removal in the order: H₂PO₄⁻ > $$ > Cl⁻ > $$ > $$. This work establishes the CNTT heterostructure as a promising, environmentally tolerant candidate for efficient pharmaceutical pollutant remediation in complex aqueous matrices.

To generate hydrogen efficiently by using visible light, it is important to investigate closely contacted halogens (Cl, Br, I)-conjugated polymer semiconductors/g-C₃N₅ heterojunction photocatalysts with photogenerated-carrier separation. This work demonstrated the successful fabrication of halogens (Cl, Br, I)-conjugated poly [3-thienylboronic acid (BA)]/g-C₃N₅ nanosheet heterojunctions for hydrogen evolution utilizing visible light. Photoluminescence spectra (PL), time-resolved photoluminescence spectra, and density functional theory suggest that the improved photocatalytic performance results from charge separation generated by photo-generated electron transfer from g-C₃N₅ to IBA. To maintain tight interface contacts, boronic acid groups [–B(OH)₂] of (Cl, Br, I) poly-BA and amino groups (–NH₂) of g-C₃N₅ exhibit hydrogen bonding interactions. When comparing the ratio-optimized 5IBA–CN to g-CN, it demonstrates a 34-fold improvement in hydrogen (H₂) production activity up to 4107.5 μmol g h⁻¹ during visible-light radiation exposure. An abundant hydrogen bonding network on the surfaces of heterojunctions facilitates the uniform layering of Pt nanoparticles as cocatalysts. This research persents a feasible method for designing heterojunctions from polymeric materials to be used as solar-light-driven photocatalysts.

The photophysical properties of a series of thermally activated delayed fluorescence emitters, comprising a nitrogen-based donor, a phenylene bridge and a boron-based acceptor, are investigated using a combination of density functional theory and multi-reference configuration interaction methods. In addition to singlet and triplet charge-transfer (CT) states, an acceptor-localized low-lying triplet state is found in all compounds. The size of the singlet–triplet gap and the energetic order of the CT and locally excited (LE) states can be modulated by regioisomerism (ortho- or para-linkage) and the chemical modification of the subunits. Spin-vibronic interactions, introduced through a Herzberg–Teller-type approach, are found to accelerate the intersystem crossing process considerably provided that the CT and LE states are close in energy.

Chemical modification of nucleic acids (oligonucleotide, DNA, and RNA) is a powerful tool, widely used in chemical biology. There is a growing interest in light-mediated nucleic acid modification within biological systems, driven by the exceptional spatiotemporal precision that light offers. Moreover, light-induced chemical modification of nucleic acids, utilizing light as an external energy source, offers a powerful and efficient alternative to conventional labor-intensive de novo synthesis. In this regard, visible light exhibits a highly efficient and selective approach, enabling precise labeling of target sites without compromising their structural integrity, while high-energy UV light triggers detrimental photochemical reactions, causing DNA/RNA damage. Light-mediated selective labeling and interstrand crosslinking of DNA/RNA duplexes hold great potential for applications in DNA repair, gene regulation, and nanotechnology. Photouncaging and photoswitching enable precise control over biological processes like transcription, RNA interference, and translation. Moreover, light-mediated DNA-encoded libraries provide a sustainable and efficient method for generating vast small-molecule libraries, valuable for pharmaceutical discovery. This review highlights recent advancements in light-mediated nucleic acid modifications, including labeling, crosslinking, photouncaging, photoswitching, and DNA-encoded library synthesis, accompanied by comprehensive discussion and analysis.

The Front Cover illustrates the light emission of the Pt(II) complex aggregate in a biological environment upon irradiation with near infrared (NIR) II laser light. The laser light can reach the deep tissue though the NIR II optical window, where the light scattering and absorption by water molecules and hemoglobin are suppressed, and directly excite the Pt(II) complex aggregate to operate as a photosensitizer in phototherapy and as a luminophore to play a role of a photoimaging agent. More information can be found in the Review Article by Shingo Hattori and Kazuteru Shinozaki (DOI: 10.1002/cptc.202500041).

Upconversion nanocrystals (UCNC) as energy converters have garnered significant attention due to their exceptional luminescent properties. However, the limited performance capabilities of single UCNC fail to meet the demands of increasing application–oriented research. To integrate multiple functionalities, UCNC–based heterostructures have been explored. These heterostructures, comprising UCNC and other functional components (transition metals, semiconductors, quantum dots, metal–organic frameworks, SiO₂, etc.), present an intriguing system in which the morphology and physicochemical properties are significantly influenced by the combination of functional units. As multifunctional hybrid architectures, UCNC–based heterostructures surmount the intrinsic limitations of individual UCNC configurations, exhibiting synergistically enhanced properties. Nevertheless, due to the chemical composition discrepancy and large lattice mismatches, the synthesis of UCNC–based heterostructures remains challenging. To date, most UCNC–based heterostructures have been fabricated through nonepitaxial growth methods, while epitaxial growth connections remain relatively limited. In this review, recent advancements in the field of UCNC–based heterostructures are summarized and trends in their biomedical applications are outlined. Finally, the challenges and potential opportunities in this field are discussed.

Achieving multicolor emissions from a single molecule has been an active field of research, particularly in developing organic light-emitting diodes. Reported herein is acenaphthylenedione (AcD), which displays multiple colors as a function of excitation wavelengths. Experimental and theoretical data reveal that the latter emits strongly from S₃ and weakly from S₂, while S₁ remains as a dark state, thus violating Kasha's rule. The calculated large energy difference between S₂ and S₃ (i.e., 1.00 eV) promotes radiative decay from S₃ rather than internal conversion (IC) to S₁. Hydrazones derived from the same also possess excitation wavelength-dependent emission. Time-dependent density functional theory (TDDFT) calculations reveal that the longer wavelength emission can be assigned to enol-form, produced through excited-state intramolecular proton transfer (ESIPT) and locally excited (LE) keto-form, while that of the shorter wavelength to LE S₂, thus disobeying Kasha's rule. The calculated energy difference (ΔE_S1-S2) is found to be 0.64 eV, which reduces the rate of IC (i.e., S₂ → S₁), resulting in the emission from the higher excited state. N-methylated hydrazone, which blocks the ESIPT channel, also supports the hypothesis. Furthermore, all the compounds exhibit aggregation-induced emission behavior, and nitro- and cyano-substituted hydrazones are found as good candidates for antibacterial, antioxidant, and anticancer activities.

The photochemistry of resveratrol with singlet oxygen (¹O₂) under blue-LED irradiation is explored in the presence of three metal-free porphyrins as photosensitizers. Irradiation at 450 nm yields products of CC bond scission, 6-electron electrocyclic ring closure, and [4 + 2] cycloaddition, including benzaldehydes, 2,4,6-trihydroxyphenanthrene, and resveratrol cyclic endoperoxide. The selectivity of the process is controlled by the structure of the metal-free porphyrin and by the nominal capacity of the blue-LED photon. The scope of the reaction is extended to sustainable heterogeneous photosensitizers produced by immobilization of metal-free porphyrins on lignin, the most abundant polyphenol in nature characterized by beneficial photochemical properties.