Photochem最新文献_第10页

Phosphorescence of Hydrogen-Capped Linear Polyyne Molecules C8H2, C10H2 and C12H2 in Solid Hexane Matrices at 20 K 氢封端的线性炔烃分子C8H2、C10H2和C12H2在固体己烷基质中的20K磷光

Photochem Pub Date : 2022-02-28 DOI: 10.3390/photochem2010014

Tomonari Wakabayashi, U. Szczepaniak, Kaito Tanaka, Satomi Saito, K. Fukumoto, R. Ohnishi, Kazunori Ozaki, Taro Yamamoto, Hal Suzuki, J. Guillemin, H. Shiromaru, T. Kodama, Miho Hatanaka

{"title":"Phosphorescence of Hydrogen-Capped Linear Polyyne Molecules C8H2, C10H2 and C12H2 in Solid Hexane Matrices at 20 K","authors":"Tomonari Wakabayashi, U. Szczepaniak, Kaito Tanaka, Satomi Saito, K. Fukumoto, R. Ohnishi, Kazunori Ozaki, Taro Yamamoto, Hal Suzuki, J. Guillemin, H. Shiromaru, T. Kodama, Miho Hatanaka","doi":"10.3390/photochem2010014","DOIUrl":"https://doi.org/10.3390/photochem2010014","url":null,"abstract":"Laser-ablated polyyne molecules, H(C≡C)nH, were separated by size in solutions and co-condensed with excess hexane molecules at a cryogenic temperature of 20 K in a vacuum system. The solid matrix samples containing C8H2, C10H2, and C12H2 molecules were irradiated with UV laser pulses and the phosphorescence 0–0 band was observed at 532, 605, and 659 nm, respectively. Vibrational progression was observed for the symmetric stretching mode of the carbon chain in the ground state with increments of ~2190 cm−1 for C8H2, ~2120 cm−1 for C10H2, and ~2090 cm−1 for C12H2. Temporal decay analysis of the phosphorescence intensity revealed the lifetimes of the triplet state as ~30 ms for C8H2, ~8 ms for C10H2, and ~4 ms for C12H2. The phosphorescence excitation spectrum reproduces UV absorption spectra in the hexane solution and in the gas phase at ambient temperature, although the excitation energy was redshifted. The symmetry-forbidden vibronic transitions were observed for C10H2 by lower excitation energies of 25,500–31,000 cm−1 (320–390 nm). Detailed phosphorescence excitation patterns are discussed along the interaction of the polyyne molecule and solvent molecules of hexane.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45081536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of the Photodynamic Effect of Two Chlorins, Photodithazine and Fotoenticine, in Gliosarcoma Cells 光二嗪和Fotoenticine两种氯对胶质瘤细胞光动力学作用的比较

Photochem Pub Date : 2022-02-25 DOI: 10.3390/photochem2010013

L. C. Fontana, J. G. Pinto, J. Magalhães, D. Tada, Rainara Moreno Sanches de Almeida, C. Pacheco-Soares, J. Ferreira-Strixino

引用次数: 2

Observation of Light-Induced Reactions of Olefin–Ozone Complexes in Cryogenic Matrices Using Fourier-Transform Infrared Spectroscopy 傅里叶变换红外光谱法观察低温基质中烯烃-臭氧配合物的光致反应

Photochem Pub Date : 2022-02-24 DOI: 10.3390/photochem2010012

F. Ito

引用次数: 1

Enhanced Photocatalytic Activity of TiO2 Thin Film Deposited by Reactive RF Sputtering under Oxygen-Rich Conditions 富氧条件下反应射频溅射制备的TiO2薄膜光催化活性的增强

Photochem Pub Date : 2022-02-18 DOI: 10.3390/photochem2010011

Takaya Ogawa, Yue Zhao, H. Okumura, K. Ishihara

引用次数: 1

Photoreactions of Sc3N@C80 with Disilirane, Silirane, and Digermirane: A Photochemical Method to Separate Ih and D5h Isomers 的光反应Sc3N@C80二硅烷、硅烷和二硅烷：分离Ih和D5h异构体的光化学方法

Photochem Pub Date : 2022-02-07 DOI: 10.3390/photochem2010010

M. Kako, K. Miyabe, Shinpei Fukazawa, Shinji Kanzawa, M. Yasui, M. Yamada, Y. Maeda, Z. Slanina, F. Uhlík, L. Adamowicz, Ilias Papadopoulos, D. Guldi, Mako Furukawa, S. Nagase, T. Akasaka

{"title":"Photoreactions of Sc3N@C80 with Disilirane, Silirane, and Digermirane: A Photochemical Method to Separate Ih and D5h Isomers","authors":"M. Kako, K. Miyabe, Shinpei Fukazawa, Shinji Kanzawa, M. Yasui, M. Yamada, Y. Maeda, Z. Slanina, F. Uhlík, L. Adamowicz, Ilias Papadopoulos, D. Guldi, Mako Furukawa, S. Nagase, T. Akasaka","doi":"10.3390/photochem2010010","DOIUrl":"https://doi.org/10.3390/photochem2010010","url":null,"abstract":"Under photoirradiation, Sc3N@Ih-C80 reacted readily with disilirane 1, silirane 4, and digermirane 7 to afford the corresponding 1:1 adducts, whereas Sc3N@D5h-C80 was recovered without producing those adducts. Based on these results, we described a novel method for the exclusive separation of Ih and D5h isomers of Sc3N@C80. The method includes three procedures: selective derivatization of Sc3N@Ih-C80 using 1, 4, and 7, facile HPLC separation of pristine Sc3N@D5h-C80 and Sc3N@Ih-C80 derivatives, and thermolysis of Sc3N@Ih-C80 derivatives to collect pristine Sc3N@Ih-C80. In addition, laser flash photolysis experiments were conducted to elucidate the reaction mechanism. Decay of the transient absorption of 3Sc3N@Ih-C80* was observed to be enhanced in the presence of 1, indicating the quenching process. When Sc3N@D5h-C80 was used, the transient absorption was much less intensive. Therefore, the quenching of 3Sc3N@D5h-C80* by 1 could not be confirmed. Furthermore, we applied time-dependent density functional theory (TD-DFT) calculations of the photoexcited states of Sc3N@C80 to obtain insights into the reaction mechanism.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48919305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Local and Remote Conformational Switching in 2-Fluoro-4-Hydroxy Benzoic Acid 2-氟-4-羟基苯甲酸的局部和远程构象转换

Photochem Pub Date : 2022-01-28 DOI: 10.3390/photochem2010009

S. Góbi, Mirjam Balbisi, György Tarczay

{"title":"Local and Remote Conformational Switching in 2-Fluoro-4-Hydroxy Benzoic Acid","authors":"S. Góbi, Mirjam Balbisi, György Tarczay","doi":"10.3390/photochem2010009","DOIUrl":"https://doi.org/10.3390/photochem2010009","url":null,"abstract":"In this work, 2-F-4-OH benzoic acid was isolated in Ar matrices and conformational changes were induced by near-IR irradiating the sample. Upon deposition, three conformers could be observed in the matrix, denoted as A1, A2, and D1, respectively. A1 and A2 are trans carboxylic acids, i.e., there is an intramolecular H bond between the H and the carbonyl O atoms in the COOH group, whereas D1 is a cis carboxylic acid with an intramolecular H bond between the F atom and the H atom in the COOH group, which otherwise has the same structure as A1. The difference between A1 and A2 is in the orientation of the carbonyl O atom with regard to the F atom, i.e., whether they are on the opposite or on the same side of the molecule, respectively. All three conformers have their H atom in their 4-OH group, facing the opposite direction with regard to the F atom. The stretching overtones of the 4-OH and the carboxylic OH groups were selectively excited in the case of each conformer. Unlike A2, which did not show any response to irradiation, A1 could be converted to the higher energy form D1. The D1 conformer spontaneously converts back to A1 via tunneling; however, the conversion rate could be significantly increased by selectively exciting the OH vibrational overtones of D1. Quantum efficiencies have been determined for the ‘local’ or ‘remote’ excitations, i.e., when the carboxylic OH or the 4-OH group is excited in order to induce the rotamerization of the carboxylic OH group. Both ‘local’ and ‘remote’ conformational switching are induced by the same type of vibration, which allows for a direct comparison of how much energy is lost by energy dissipation during the two processes. The experimental findings indicate that the ‘local’ excitation is only marginally more efficient than the ‘remote’ one.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47507962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

UV Photolysis Study of Para-Aminobenzoic Acid Using Parahydrogen Matrix Isolated Spectroscopy 紫外光解对氨基苯甲酸的对氢基分离光谱研究

Photochem Pub Date : 2022-01-26 DOI: 10.3390/photochem2010008

Alexandra McKinnon, B. Moore, Pavle Djuricanin, T. Momose

{"title":"UV Photolysis Study of Para-Aminobenzoic Acid Using Parahydrogen Matrix Isolated Spectroscopy","authors":"Alexandra McKinnon, B. Moore, Pavle Djuricanin, T. Momose","doi":"10.3390/photochem2010008","DOIUrl":"https://doi.org/10.3390/photochem2010008","url":null,"abstract":"Many sunscreen chemical agents are designed to absorb UVB radiation (and in some cases UVA) to protect the skin from sunlight, but UV absorption is often accompanied by photodissociation of the chemical agent, which may reduce its UV absorption capacity. Therefore, it is important to understand the photochemical processes of sunscreen agents. In this study, the photolysis of para-aminobenzoic acid (PABA), one of the original sunscreen chemical agents, at three different UV ranges (UVA: 355 nm, UVB: >280 nm, and UVC: 266 nm and 213 nm) was investigated using parahydrogen (pH2) matrix isolation Fourier-Transform Infrared (FTIR) Spectroscopy. PABA was found to be stable under UVA (355 nm) irradiation, while it dissociated into 4-aminylbenzoic acid (the PABA radical) through the loss of an amino hydrogen atom under UVB (>280 nm) and UVC (266 nm and 213 nm) irradiation. The radical production supports a proposed mechanism of carcinogenic PABA-thymine adduct formation. The infrared spectrum of the PABA radical was analyzed by referring to quantum chemical calculations, and two conformers were found in solid pH2. The PABA radicals were stable in solid pH2 for hours after irradiation. The trans-hydrocarboxyl (HOCO) radical was also observed as a minor secondary photoproduct of PABA following 213 nm irradiation. This work shows that pH2 matrix isolation spectroscopy is effective for photochemical studies of sunscreen agents.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42912672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nanostructured Luminescent Micelles: Efficient “Functional Materials” for Sensing Nitroaromatic and Nitramine Explosives 纳米结构发光胶束：用于感测硝基芳烃和硝胺炸药的高效“功能材料”

Photochem Pub Date : 2022-01-10 DOI: 10.3390/photochem2010004

Shashikana Paria, Prasenjit Maity, Rafia Siddiqui, R. Patra, S. B. Maity, A. Jana

{"title":"Nanostructured Luminescent Micelles: Efficient “Functional Materials” for Sensing Nitroaromatic and Nitramine Explosives","authors":"Shashikana Paria, Prasenjit Maity, Rafia Siddiqui, R. Patra, S. B. Maity, A. Jana","doi":"10.3390/photochem2010004","DOIUrl":"https://doi.org/10.3390/photochem2010004","url":null,"abstract":"Luminescent micelles are extensively studied molecular scaffolds used in applied supramolecular chemistry. These are particularly important due to their uniquely organized supramolecular structure and chemically responsive physical and optical features. Various luminescent tags can be incorporated with these amphiphilic micelles to create efficient luminescent probes that can be utilized as “chemical noses” (sensors) for toxic and hazardous materials, bioimaging, drug delivery and transport, etc. Due to their amphiphilic nature and well-defined reorganized self-assembled geometry, these nano-constructs are desirable candidates for size and shape complementary guest binding or sensing a specific analyte. A large number of articles describing micellar fluorogenic probes are reported, which are used for cation/anion sensing, amino acid and protein sensing, drug delivery, and chemo-sensing. However, this particular review article critically summarizes the sensing application of nitroaromatic (e.g., trinitrotoluene (TNT), trinitrobenzene (TNB), trinitrophenol (TNP), dinitrobenzene (DNB), etc.) and nitramine explosives (e.g., 1,3,5-trinitro-1,3,5-triazinane, trivially named as “research department explosive” (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, commonly known as “high melting explosive” (HMX) etc.). A deeper understanding on these self-assembled luminescent “functional materials” and the physicochemical behavior in the presence of explosive analytes might be helpful to design the next generation of smart nanomaterials for forensic applications. This review article will also provide a “state-of-the-art” coverage of research involving micellar–explosive adducts demonstrating the intermolecular charge/electron transfer (CT/ET) process operating within the host–guest systems.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46802304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Plant Photochemistry, Reactive Oxygen Species, and Photoprotection 植物光化学、活性氧和光防护

Photochem Pub Date : 2021-12-30 DOI: 10.3390/photochem2010002

Michael Moustakas

引用次数: 24

Autofluorescence Spectroscopy and Imaging II: A Special Issue Aimed to Promote Optically Based Studies on Biological Substrates 自荧光光谱与成像II：旨在促进生物基质光学研究的特刊

Photochem Pub Date : 2021-12-29 DOI: 10.3390/photochem2010001

A. C. Croce

引用次数: 1