Journal of Photochemistry and Photobiology A-chemistry最新文献

{"title":"Synthesis of MCG700B(X) composites and their performance in CO₂ capture and photocatalytic reduction","authors":"Ayixia Qiong ,&nbsp;Kaiqiang Liu ,&nbsp;Honghao Li ,&nbsp;Nasiman Tuerxun","doi":"10.1016/j.jphotochem.2025.116774","DOIUrl":"10.1016/j.jphotochem.2025.116774","url":null,"abstract":"<div><div>In this study, a biomass-derived adsorbent was synthesized by calcining spent coffee grounds (SCGs) with metal oxides at high temperatures. Among the prepared materials, MCG₇₀₀, comprising MgO and biochar derived from SCGs at 700 °C, exhibited the most outstanding CO₂ adsorption capacity, reaching 43.59 cm³ g⁻¹ STP at 0 °C. Impressively, after five adsorption-desorption cycles (0 °C, 0.01–1 bar), MCG₇₀₀ retained 95 % of its original adsorption capacity, demonstrating excellent recyclability. Furthermore, a novel flower-like biochar-based BiOCl photocatalyst enriched with oxygen vacancies (OVs) was successfully fabricated via a combined impregnation–hydrothermal method. When the mass ratio of BiOCl to MCG₇₀₀ was 1:1, the composite achieved the highest CO₂ photoreduction efficiency, with a CO yield of 71.16 μmol g⁻¹. The incorporation of biochar markedly enhanced charge separation efficiency, increased photocurrent density, reduced charge transfer resistance, and significantly improved CO₂ capture capability. These synergistic effects promoted the generation of reactive species and ultimately led to a remarkable enhancement in photocatalytic performance.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116774"},"PeriodicalIF":4.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giant enhancement in upconversion luminescence of negative thermal quenching Sc2W3O12: Yb3+/Er3+ phosphors by Ca2+ ions doping for multi-mode temperature sensing","authors":"Yuanyuan Fan ,&nbsp;Yongtao Liu ,&nbsp;Shun Li ,&nbsp;Bin Duan ,&nbsp;Daobin Zhu ,&nbsp;Keyu Guo ,&nbsp;Rangrang Fan ,&nbsp;Chunfeng Dong ,&nbsp;Wei Jin ,&nbsp;Junshan Hu","doi":"10.1016/j.jphotochem.2025.116771","DOIUrl":"10.1016/j.jphotochem.2025.116771","url":null,"abstract":"<div><div>Upconversion luminescence (UCL) intensity is a critical issue for negative thermal quenching material with high phonon energy. In this work, the phosphors of Sc₂W₃O₁₂: Yb³⁺/Er³⁺/Ca²⁺ (SWO: Er/Yb/Ca) were prepared by high-temperature solid-phase method, and the multi-mode UCL characteristics of SWO: Er/Yb/Ca excited by 980 nm laser. The optimal doping concentration for Ca²⁺ ions is 15 %. Compared with the sample without Ca²⁺ ions, the green and red emission intensities of the phosphor were increased by 306.33 times and 23.45 times, respectively. It presents three characteristic emission peaks in the visible region: (528 nm, ²H_11/2 → ⁴I_15/2), (551 nm, ⁴S_3/2 → ⁴I_15/2), (657 nm, ⁴F_9/2 → ⁴I_15/2). The absorption spectrum, UCL spectrum and downconversion luminescence spectra of Sc₂W₃O₁₂:Yb³⁺/Er³⁺/Ca²⁺ were analyzed. A multi-mode temperature sensing system was innovatively constructed, covering three independent temperature sensing channels: (1) by constructing a Boltzmann distribution model of the thermal coupling energy level (²H_11/2-⁴S_3/2), the maximum relative sensitivity S_R = 0.247 % K⁻¹ was obtained at 523 K; (2) Combined with the non-thermally coupled energy level (²H_11/2-⁴F_9/2) and fluorescence intensity ratio (FIR) for temperature-dependent analysis, the relative sensitivity reached a peak of 0.962 % K⁻¹ at 298 K. (3) S_R = 0.403 % K⁻¹ at 523 K is achieved by cross-relaxation compensation mode (⁴S_3/2-⁴F_9/2), which provides new materials and ideas for non-contact multi-mode temperature sensing.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116771"},"PeriodicalIF":4.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dramatically enhanced broadband reverse saturable absorption of anthracene derivatives: Regulatory effect of π-bridge in two-branched molecules","authors":"Jidong Jia ,&nbsp;Tianwei Zhang ,&nbsp;YinLin Lu ,&nbsp;Xingzhi Wu ,&nbsp;Yinglin Song","doi":"10.1016/j.jphotochem.2025.116768","DOIUrl":"10.1016/j.jphotochem.2025.116768","url":null,"abstract":"<div><div>Polycyclic aromatic hydrocarbons (PAHs) are widely employed in laser protection applications owing to their excellent nonlinear optical absorption (NLA) properties. Nevertheless, the underlying enhancement mechanisms governing their NLA performance, particularly concerning structure-property relationships, remain ambiguous. To study the influence of π-bridges on nonlinear optical absorption (NLA) performance and excited-state dynamics, we designed and synthesized three two-branched anthracene derivatives (ZN1, ZN2, and ZN3) in this work. By introducing different π-bridges, we modulate the dihedral angle θ between the anthracene core and side chains in these two-branched molecules from 90° to 0°, thereby governing their electron transition characteristics. Through an integrated computational-experimental framework, we elucidate the distinct excitation pathways in these systems—including intramolecular charge transfer (ICT) and local excitation (LE)—by employing hole-electron analysis and transient absorption spectroscopy. Reducing the dihedral angle θ facilitates orbital overlap between the conjugated core and side chains, which extends the π-conjugated system and significantly augments the molecule's reverse saturable absorption (RSA) performance. Based on the above molecular optimization strategy, we have successfully improved the ultrafast broadband optical limiting (OL) performance of these compounds (515–650 nm), with an OL threshold as low as 9.11 mJ/cm².</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116768"},"PeriodicalIF":4.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photochemical transformation of dichloromethane to chloroform: insights into the mechanism of aza[5]helicene photoprotonation","authors":"Veronica S. Tamozhnikova ,&nbsp;Yuri P. Tsentalovich ,&nbsp;Ilia V. Eltsov ,&nbsp;Alexander A. Buravlev ,&nbsp;Roman Yu. Balakhonov ,&nbsp;Igor S. Mekeda ,&nbsp;Valerii Z. Shirinian ,&nbsp;Lei Wang ,&nbsp;Evgeni M. Glebov","doi":"10.1016/j.jphotochem.2025.116767","DOIUrl":"10.1016/j.jphotochem.2025.116767","url":null,"abstract":"<div><div>Aza[5]helicenes of the furoquinoline series have two important features: (a) possibility to modulate photophysical properties by protonation, and (b) they are good fluorophores that exhibit exceptional photostability in chlorine-free organic solvents. Light irradiation in chlorine-containing solvents was known to result in photoprotonation. In this work photophysics and photochemistry of a typical aza[5]helicene, namely 3-methoxy-6-(4-methoxyphenyl)naphtho[1′,2′:4,5]furo[2,3-<em>c</em>]quinoline (compound <strong>Hel</strong>) in dichloromethane (DCM) was studied using stationary photolysis with UV–Vis and NMR registration, time-resolved fluorescence and nanosecond laser flash photolysis. The free base aza[5]helicene was found for the first time to promote the transformation of dichloromethane to chloroform upon irradiation with UV light (308 nm). Studies of the quantitative characteristics of <strong>Hel</strong> and <strong>HelH</strong>^{<strong>+</strong>} (fluorescence quantum yields, spectra and kinetic properties of the triplet states –showed that photoprotonation occurs in two ways. The first pathway is started by an electron transfer from an excited <strong>Hel</strong> molecule to a solvent molecule, followed by an H atom transfer from a solvent molecule to the <strong>Hel</strong>^{<strong><img>+</strong>} radical cation. The second pathway of <strong>HelH</strong>^{<strong>+</strong>} formation is the reaction between <strong>Hel</strong> and HCl formed at the first stage. A quantitative mechanism of photoprotonation is proposed that explains all the observed experimental data.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116767"},"PeriodicalIF":4.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of antioxidants in edible oils using surface-enhanced Raman spectroscopy combined with machine learning","authors":"Shixin Wang,&nbsp;Daolin Yang,&nbsp;Xijun Wu,&nbsp;Zherui Du,&nbsp;Xin Zhang,&nbsp;Xuan Zhao,&nbsp;Jiangtao Wang,&nbsp;Xuan Zhao,&nbsp;Yungang Zhang","doi":"10.1016/j.jphotochem.2025.116760","DOIUrl":"10.1016/j.jphotochem.2025.116760","url":null,"abstract":"<div><div>Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ) are three commonly used synthetic antioxidants, often added to edible oils to prevent oxidation. However, their use is limited due to the toxicity. In this study, gold nanoparticles (AuNPs) were synthesized as a surface-enhanced Raman spectroscopy (SERS) substrate for the rapid detection of antioxidant types and concentrations in edible oils. Rhodamine was introduced as a probe molecule to verify the substrate's performance, and the enhancement factor was determined to be 4.4 × 10⁵. Using the fabricated substrate, trace detection of antioxidants was achieved in the concentration range of 1000 mg/kg to 20 mg/kg, with a detection limit below 10 mg/kg. Additionally, several machine learning algorithms were employed to establish models for the classification and over-limit detection of antioxidants, achieving accuracies of exceeding 99 % and 94 %, respectively. These results demonstrate that SERS combined with machine learning is effective for detecting antioxidants in edible oils.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116760"},"PeriodicalIF":4.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New fluorescent coumarin dyes containing functional acceptor groups: The investigation of photophysical, optical, and thermal properties","authors":"Ergin Keleş ,&nbsp;Ebubekir Kandemir ,&nbsp;Burcu Aydıner ,&nbsp;Nurgül Seferoğlu ,&nbsp;Zeynel Seferoğlu","doi":"10.1016/j.jphotochem.2025.116766","DOIUrl":"10.1016/j.jphotochem.2025.116766","url":null,"abstract":"<div><div>Nine novel coumarin-based compounds with a donor-π-acceptor system were synthesized, and their structural characterizations were determined by spectroscopic methods. The effects of different acceptor groups, such as dicyanovinyl, cyanoacrylic acid, and rhodanine-3-acetic acid at the 3-position of the coumarin ring, on the electronic and optical properties of the structure were investigated. Moreover, the coumarin structure was derived by adding an electron donor methoxy group, and a fused benzene ring, which also increases the planar structure. Synthesized compounds' absorption and emission properties are strongly influenced by substitution in the coumarin moiety. Four dyes showed near-IR emission in the solid state with green to orange fluorescence under UV light. The structural and electronic properties of the molecules were obtained with the DFT calculations at B3LYP/6-311++g(d,p) level of theory. The frontier molecular orbitals and the global reactivity descriptors were computed. Additionally, some DSSC parameters for <strong>3a-c</strong> and <strong>5a-c</strong> were also determined to provide insight into their potential. All compounds showed good thermal stability (Td &gt; 200 °C).</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116766"},"PeriodicalIF":4.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing photocatalytic partial oxidation of methane to methanol: Experimental investigation of 2D/metal oxide composite catalysts","authors":"Amira Chebbi ,&nbsp;Alessandro Sinopoli ,&nbsp;Ahmed Abotaleb ,&nbsp;Muhammad Anwar ,&nbsp;Yusuf Bicer","doi":"10.1016/j.jphotochem.2025.116765","DOIUrl":"10.1016/j.jphotochem.2025.116765","url":null,"abstract":"<div><div>This study investigates the potential of photocatalytic processes for the selective conversion of methane into valuable liquid fuels, particularly methanol, addressing the need for efficient, alternative, and clean energy carriers and fuels. Two pristine photocatalysts, W₁₈O₄₉ and g-C₃N₄, along with their respective composite W₁₈O₄₉/g-C₃N₄, were synthesized and analyzed using SEM, TEM, XRD, XPS, BET, and UV-VIS spectroscopy techniques. Additionally, transient photocurrent measurements and electrochemical impedance spectroscopy (EIS) were conducted to elucidate charge transfer mechanisms and interfacial properties of the photocatalysts. The photocatalytic performance was evaluated under both visible and UV light conditions. Among the three catalysts tested, the composite W₁₈O₄₉/g-C₃N₄ demonstrated remarkable catalytic activity of 62.3 μmol g⁻¹ h⁻¹ under visible light, nearly 4-fold higher than pristine W₁₈O₄₉ and 5-fold higher than g-C₃N₄. The enhanced performance is attributed to the forming of a <em>Z</em>-scheme heterojunction system, as evidenced by XPS analysis showing increased oxygen vacancy density and strong electronic coupling between the components, further confirmed by electrochemical characterization revealing improved charge separation efficiency. This composite system offers a sustainable and cost-effective alternative to noble metal-based catalysts for photocatalytic methane conversion, demonstrating significant potential for clean energy production and greenhouse gas mitigation.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116765"},"PeriodicalIF":4.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of AgBr/Ag3PO4/GdFeO3 composite photocatalyst and its high-efficiency photocatalytic performance in degradation of norfloxacin","authors":"Maojie Zhang ,&nbsp;Pengfei Zhu ,&nbsp;Xinglin Li ,&nbsp;Yu Chen ,&nbsp;Xuemei Chen","doi":"10.1016/j.jphotochem.2025.116759","DOIUrl":"10.1016/j.jphotochem.2025.116759","url":null,"abstract":"<div><div>The antibiotic contamination in water bodies poses a serious threat to human health and ecological balance, and urgent measures are needed to purify it. In this study, a novel AgBr/Ag₃PO₄/GdFeO₃ composite photocatalyst was prepared via ultrasound dispersion method, and it was used for the photocatalytic degradation of antibiotics such as norfloxacin(NOR) in water. Under optimal conditions, the degradation rate of 20 mg/L NOR by AgBr/Ag₃PO₄/GdFeO₃ reached 82.94 %, demonstrating superior photocatalytic activity compared to AgBr, Ag₃PO₄, GdFeO₃, and AgBr/Ag₃PO₄, and it also has good stability for repeated use and wide applicability. The relevant characterization results reveal that the main reason for the enhanced photocatalytic activity of AgBr/Ag₃PO₄/GdFeO₃ is that the combination of AgBr and GdFeO₃ with Ag₃PO₄ enhances its visible light response capability, increases its surface area, and constructs a dual <em>Z</em>-scheme heterojunction. Furthermore, the wheat seedling bioassay indicated that the photodegraded NOR solution exhibited a marked reduction in phytotoxicity. Finally, a dual <em>Z</em>-scheme electron transfer mechanism of AgBr/Ag₃PO₄/GdFeO₃ was proposed, along with several possible pathways for the photocatalytic degradation of NOR. This study provides new insights for the improvement of Ag₃PO₄-based photocatalyst and offers a new reference for the treatment of wastewater containing NOR.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116759"},"PeriodicalIF":4.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally activated delayed fluorescence-assisted thermosensing and thermochromic behaviors of bimetallic lanthanide(III) complexes based on heteroditopic phenanthroline-terpyridine ancillary ligand","authors":"Toushique Ahmed,&nbsp;Tuhin Abedin,&nbsp;Sujoy Baitalik","doi":"10.1016/j.jphotochem.2025.116749","DOIUrl":"10.1016/j.jphotochem.2025.116749","url":null,"abstract":"<div><div>Syntheses and characterization of a new array of four homobimetallic Ln^III-complexes of type {(Ln₂(tta)₆(phen-Hbzim-tpy)} have been carried out in this work, where Ln = La^III (<strong>1</strong>), Eu^III (<strong>2</strong>), Sm^III (<strong>3</strong>), and Tb^III (<strong>4</strong>); tta = 2-thenoyltrifluoroacetonate and phen-Hbzim-tpy = 2-[4-(2,6-dipyridin-2-ylpyridin-4-yl)phenyl]-1H-imidazole[4,5-f] [1,10] phenanthroline. Detailed room temperature photophysical behaviors and temperature-dependent luminescence spectral characteristics of the complexes, including free phen-Hbzim-tpy ligand, have been thoroughly explored. The ancillary ligand appears to be thermally activated delayed fluorescence (TADF)-active, supported by delayed luminescence measurements as well as DFT study. All the four complexes are found to exhibit excellent thermo-responsive luminescence attributes as indicated by their <em>S</em>_<em>m</em> values (1.01 for complex <strong>1</strong>; 3.2 and 11.9 for <strong>2</strong>; 7.2 and 4.6 for <strong>3</strong>; and 2.16 for <strong>4</strong>). Complex <strong>1</strong> cannot sustain the TADF event, whereas the rest of the complexes show remarkable thermochromism owing to this TADF as well as because of their dual emission characteristics. To the best of our knowledge, this is the first report of TADF-assisted thermosensing and thermochromism from Ln^III-based discrete molecules. Attempts have also been made to elucidate how the low-lying T₁ of tta prevents the TADF event in La-complex or compels the Tb-complex to undergo back-energy-transfer via plausible energy transfer pathways, and at the same time, how three of them can show off TADF-assisted thermochromism phenomena.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116749"},"PeriodicalIF":4.7,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The lowest excited triplet state of potassium 4-methoxysalicylate (4-MSK), a skin-whitening active ingredient, and its effects on riboflavin-photosensitized singlet oxygen generation","authors":"Soichiro Hisanaga ,&nbsp;Shin Hirokawa ,&nbsp;Kazuyuki Miyazawa ,&nbsp;Mikio Yagi ,&nbsp;Azusa Kikuchi","doi":"10.1016/j.jphotochem.2025.116743","DOIUrl":"10.1016/j.jphotochem.2025.116743","url":null,"abstract":"<div><div>Potassium 4-methoxysalicylate (4-MSK) is a skin-whitening active ingredient used in skincare products. The lowest excited triplet (T₁) states of 4-MSK and its related molecules, sodium 4-aminosalicylate (4-ASNa) and 4-(trifluoromethyl)salicylic acid (4-FMSA), have been studied through measurements of phosphorescence and electron paramagnetic resonance in ethanol at 77 K. The energy levels, lifetimes and zero-field splitting (ZFS) parameters of the T₁ states of 4-MSK, 4-ASNa and 4-FMSA were determined. The observed ZFS parameters and T₁ lifetimes suggest that the T₁ states of these molecules are assigned to ³ππ^⁎ states. Riboflavin (RF) is a water-soluble vitamin B₂ and an efficient singlet oxygen photosensitizer. Time profiles of the near-IR phosphorescence of singlet oxygen generated by RF-photosensitization have been measured in the absence and presence of 4-MSK, 4-ASNa and 4-FMSA. These molecules suppress the RF-photosensitized singlet oxygen generation. The fluorescence and transient absorption measurements suggest that the observed suppression is due mainly to the quenching of the T₁ state of RF by 4-MSK, 4-ASNa and 4-FMSA. The T₁ energy levels of the quenching molecules are higher than that of RF. The triplet–triplet energy transfer from RF to the quenching molecules is energetically unlikely. The most probable quenching mechanism is the photoinduced electron transfer from the quenching molecules to the T₁ state of RF.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"472 ","pages":"Article 116743"},"PeriodicalIF":4.7,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}