Article
Chemistry, Physical
Chaochao Qin, Hua Liu, Simei Sun, Zhongpo Zhou, Yufang Liu
Summary: The photoinduced dynamics of excited-state intramolecular proton transfer (ESIPT) and vibration relaxation (VR) of 1,8-DHAQ in ethanol were investigated using time-resolved transient absorption spectroscopy and quantum chemical calculations. The results showed dual fluorescence from the S-1 state, with ESIPT process occurring in 96.8 fs and VR process in 4.1 ps, leading to the decay of the tautomer S-1 state within 269.1 ps. This mechanism was summarized through a schematic diagram of four electronic states and vibrational energy levels.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Multidisciplinary
Jonghyuk Im, Jongchan Lee, Jung Ho Lee
Summary: This article introduces a two-dimensional time-resolved photo-CIDNP experiment that is suitable for analyzing intrinsically disordered proteins (IDPs). The method was validated and compared with other methods, highlighting the importance of dye charge in the photo-CIDNP process. The study confirmed the surface accessibility of alpha-synuclein (alpha-Syn) and investigated the conformational changes induced by divalent cations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Francesco Rigodanza, Nadia Marino, Alessandro Bonetto, Antonio Marcomini, Marcella Bonchio, Mirco Natali, Andrea Sartorel
Summary: The cobalt substituted polyoxotungstate Co6 displays fast electron transfer kinetics to photogenerated Ru-III(bpy)(3)(3+), significantly faster than cobalt oxide nanoparticles. Mechanistic evidence suggests that the oxidation and transformation processes of Co6 under different pH conditions involve specific Co(II) aquo and hydroxo groups, and proceed through bimolecular kinetics or concerted proton electron transfer (CPET) mechanisms.
Article
Chemistry, Physical
Leo Mandic, Margareta Sohora, Branka Mihaljevic, Laszlo Biczok, Nikola Basaric
Summary: Reactivity in photoinduced electron transfer reactions (PET) was investigated in molecules with varying distances between the electron donor and acceptor, revealing factors such as distance, reversible PET, and back electron transfer processes affecting reaction rates. The study highlighted the importance of understanding intramolecular PET processes for rational design of various applications.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Namasivayam Dhenadhayalan, Angel Shaji Veeranepolian Selvi, Selvaraju Chellappan, Viruthachalam Thiagarajan
Summary: The dynamics of photoionization and photoinduced electron transfer of coumarin 450 in micelles were investigated in micro to femtosecond time domains using spectroscopy. The study found that ultrafast PET between amine and C450 can quench the fluorescence intensity and lifetime of C450.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Qianghua Lin, Manabu Abe
Summary: A new chromophore, NPI, was synthesized as a potential photolabile protecting group, and caged benzoic acids featuring this chromophore were found to release benzoic acid in moderate yields upon photolysis, along with the formation of aldehyde products. Under photolysis conditions, the functional group at the indole nitrogen was transformed into an aldehyde group. Intramolecular electron transfer was determined to be crucial for the formation of the aldehyde, demonstrating potential applications in transition metal-free oxidation of amino acids.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2021)
Article
Engineering, Environmental
Chu Chu, Shengye Jin, Richard Spinney, Dionysios D. Dionysiou, Haijun Zhang, Ruiyang Xiao
Summary: This article introduces the application of laser flash photolysis (LFP) in transient radical processes. By introducing the development process, principles, and compositions of LFP, comparing the specificity and suitability of different spectral modes, and discussing the generation, detection, and environmental implications of hydroxyl radicals, sulfate radicals, and reactive chlorine species, a critical review of the implementation of LFP for kinetic quantification and mechanism elucidation is conducted. The remaining challenges and future perspectives are highlighted.
Article
Chemistry, Multidisciplinary
Toshiyuki Uesaka, Tomoyuki Ishitani, Takahito Shimeno, Naoya Suzuki, Shigeyuki Yagi, Takeshi Maeda
Summary: This article presents a method to retard the photodegradation of fluorophores by covalently attaching benzotriazole units. The results show that the dyes with covalently linked benzotriazole units have a higher resistance against degradation, mainly due to the preferential absorption of harmful UV light and involvement in nonradiative deactivation by benzotriazole units.
Article
Oncology
Houda Kacem, Serena Psoroulas, Gael Boivin, Michael Folkerts, Veljko Grilj, Tony Lomax, Adrien Martinotti, David Meer, Jonathan Ollivier, Benoit Petit, Sairos Safai, Ricky A. Sharma, Michele Togno, Marta Vilalta, Damien C. Weber, Marie -Catherine Vozenin
Summary: The study investigated the physico-chemical and biological responses to conventional and UHDR electron and proton beams, including conventional photons. The temporal structure and nature of the beams had an impact on both, with electron beams at >= 1400 Gy/s and proton beams at 0.1 and 1260 Gy/s found to have an isoefficient effect on sparing zebrafish embryos.
RADIOTHERAPY AND ONCOLOGY
(2022)
Article
Chemistry, Physical
Chunfan Yang, Fang Wang, Qian Zhou, Jialong Jie, Hongmei Su
Summary: This study investigates the fluorescence quenching dynamics of AMND in AP-containing DNA single/double strands and reveals that AMND only targets cytosine to form a pseudo-base pair. Subtle conformational variations induced by different flanking nucleobases are found to modulate efficiencies of electron transfer and fluorescence quenching, providing critical mechanistic insights for the design of fluorescent ligands for single-base recognition.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Oncology
Felipe A. Calvo, Adriana Ayestaran, Javier Serrano, Mauricio Cambeiro, Jacobo Palma, Rosa Meirino, Miguel A. Morcillo, Fernando Lapuente, Luis Chiva, Borja Aguilar, Diego Azcona, Diego Pedrero, Javier Pascau, Jose Miguel Delgado, Javier Aristu, Yolanda Prezado
Summary: This study investigated the feasibility of combining proton therapy and intraoperative electron radiation therapy to treat recurrent and unresectable localized cancer. The results showed that this strategy was effective in certain specific cases.
FRONTIERS IN ONCOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Ol'ha O. Brovarets', Alona Muradova, Dmytro M. Hovorun
Summary: A comprehensive investigation was conducted on the physico-chemical mechanisms of 55 conformational transformations of biologically-important G·C nucleobase pairs. It was found that these pairs can transform into each other through non-planar transition states without changing the tautomeric status of the bases, with key involvement of intermolecular hydrogen bonds. The fast reactions are accompanied by disruption and formation of specific contacts between the bases.
Article
Chemistry, Multidisciplinary
Rui Sun, Serge Ruccolo, Daniel L. Nascimento, Yangzhong Qin, Nathaniel Hibbert, Daniel G. Nocera
Summary: Triplet excited states of ketones can selectively abstract hydrogen atoms from amide N-H bonds without affecting weaker C-H bonds through a proton-coupled electron transfer pathway. This chemoselectivity arises from the asynchronicity between electron and proton transfer in the PCET process, which is determined by the differences in ionization energies of functional groups rather than bond dissociation energies. We demonstrate the application of this strategy in achieving intramolecular anti-Markovnikov hydroamidation of alkenes using camphorquinone as an inexpensive and sustainable photocatalyst.
Article
Environmental Sciences
Camille K. Amador, Daniel J. Van Hoomissen, Jiaoqin Liu, Timothy J. Strathmann, Shubham Vyas
Summary: Recent reports highlight the potential of technologies generating hydrated electrons for the destruction of per- and polyfluoroalkyl substances. This study examines the kinetics and mechanisms of these technologies when reacting with ultra-short chain fluorocarboxylates. The results demonstrate a wide range of rate constants and suggest that the reduction of fluorocarboxylates by hydrated electrons occurs through divergent mechanisms.
Article
Multidisciplinary Sciences
Clorice R. Reinhardt, Daniel Konstantinovsky, Alexander Soudackov, Sharon Hammes-Schiffer
Summary: This article presents a kinetic model that describes the reversible radical transfer in the enzyme ribonucleotide reductase (RNR). The model is based on experimental studies and provides insights into the time evolution and factors influencing radical transport in RNR.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Physical
Min Zheng, Yuanming Li, Yaxiong Wei, Lin Chen, Shilin Liu, Xiaoguo Zhou
Summary: Thermally activated delayed fluorescence (TADF) molecules are promising triplet photosensitizers for practical applications due to their long triplet lifetimes, low energy loss, and efficient light harvesting. In this study, a new TTA upconversion system using a recently developed TADF molecule, DMACPDO, as the triplet photosensitizer and 9,10-diphenylanthracene (DPA) as the annihilator was investigated. The results showed relatively high upconversion yields in different solvents, and the influence of solvent polarity and viscosity on the photophysical and photochemical processes was explored.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Xiaodong Chen, Lei Xing, Xinfei Li, Ning Chen, Liming Liu, Jionghan Wang, Xiaoguo Zhou, Shilin Liu
Summary: As manganese ions (Mn2+) are a risk factor for neurodegenerative diseases, understanding their effect on protein amyloid fibril formation is crucial. This study used various techniques to investigate the influence of Mn2+ on the fibrillation kinetics of hen egg white-lysozyme (HEWL). The results revealed that Mn2+ accelerated the unfolding of the protein structure, leading to the formation of oligomers and amorphous aggregates instead of amyloid fibrils. Mn2+ also played a role in the transition of secondary structures, promoting the formation of beta-sheet structures.
Article
Chemistry, Physical
Yan Chen, Xiangkun Wu, Tongpo Yu, Xiaoguo Zhou, Bing Yan, Shilin Liu
Summary: In this study, two-dimensional potential energy surfaces along the N-NO bond length and N-N-O bond angle of N2O+ in the A2 sigma+ and B2 pi states were calculated using CASPT2/cc-pVQZ level. A new N-NO bond fission pathway was proposed in the bent geometry of the A2A'(A2 sigma+) state, which has a lower barrier compared to the known decomposition mechanisms in linear structure. Additionally, the contributions of the A' and A'' components split from the B2 pi state were clarified, and the effect of avoided crossing and spin state coupling on the ro-vibrational distributions of the NO+ fragment ion observed in experiments were explained.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Zhiwen Luan, Yanlin Fu, Yuxin Tan, Yaling Wang, Anwen Liu, Tao Wang, Xiaoguo Zhou, Bina Fu, Dong H. Zhang, Daofu Yuan, Xingan Wang, Xueming Yang
Summary: The photodissociation dynamics of H2S+ were studied using the VMI technique and high-accuracy calculations. Ion images of S+(S-4) products were measured at different photolysis wavelengths. The product rotational state and anisotropy parameter distributions were found to be dependent on the photolysis wavelength. Nonadiabatic coupling and symmetry relaxation were identified as key factors in the photodissociation process.
CHINESE JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Wenjin Cao, Qinqin Yuan, Hanhui Zhang, Xiaoguo Zhou, Steven R. Kass, Xue-Bin Wang
Summary: We conducted a study on glycine-chloride/bromide complexes (Gly center dot X-, X = Cl/Br) using negative ion photoelectron spectroscopy and quantum chemical computations, comparing them with the previously studied Gly center dot I- cluster ion. Through experimental and theoretical analysis, we found that different Gly center dot X- complexes adopt the same types of low-lying isomers with varying relative energies. Despite the congested spectral profiles, spectral assignments for Gly center dot Cl- and Gly center dot Br- were accomplished with the guidance from Gly center dot I-, which has well-resolved spectral peaks. This study investigates the binding patterns of glycine complexes with different halides, demonstrating that iodide-tagging is an effective spectroscopic method for unraveling diverse ion-molecule binding motifs in cluster anions with congested spectral bands.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Instruments & Instrumentation
Tongpo Yu, Xinlang Yang, Zhi Gao, Baokun Shan, Lei Xu, Xiaoguo Zhou, Shilin Liu
Summary: Time-sliced velocity map imaging (VMI) is commonly used in studies of photodissociation dynamics. However, its time resolution is often not sufficient to distinguish adjacent m/z ions with the same kinetic energy. In this study, a novel switch design for common ion optics in three-dimensional (3D) VMI was introduced, allowing a convenient switch between 2D and 3D VMI without breaking the vacuum or replacing the electrostatic plates, resulting in improved time resolution while maintaining high energy resolution.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Spectroscopy
Liming Liu, Xinfei Li, Ning Chen, Xiaodong Chen, Lei Xing, Xiaoguo Zhou, Shilin Liu
Summary: This study investigated the influence of Cd(II) ions on the denaturation kinetics of hen egg white lysozyme (HEWL) under thermal and acidic conditions. Various techniques including Raman spectroscopy, fluorescence, AFM imaging, circular dichroism spectroscopy, and transmittance assays were employed to analyze the structural changes. The results showed that Cd(II) ions efficiently accelerated the disruption of tertiary structure and promoted the direct formation of organized β-sheets from α-helices. Furthermore, Cd(II) ions facilitated the assembly of initially disordered oligomers into aggregates with random structures similar to gels instead of amyloid fibrils, indicating an off-pathway denaturation pathway. These findings enhance the understanding of ion-specific effects.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Multidisciplinary Sciences
Jia Han, Lei Wang, Wenjin Cao, Qinqin Yuan, Xiaoguo Zhou, Shilin Liu, Xue-Bin Wang
Summary: Singlet oxygen (O-1(2)) has the potential for selective degradation of dyes in wastewater remediation, and it can be effectively generated through the reaction between an anion complex ([HFIP-H](-)) and hydroperoxyl radical (center dot HO2) through UV photodetachment. A novel "photogeneration" strategy is proposed to produce O-1(2) through the incorporation of atmospheric O-2 and HFIP, acting as a catalyst. This study sheds new light on potential water purification by achieving different degradation levels of dye molecules in a controllable fashion.
Article
Chemistry, Physical
Jia Han, Yang Yang, Binglin Qiu, Pengcheng Liu, Xiangkun Wu, Guanjun Wang, Shilin Liu, Xiaoguo Zhou
Summary: We conducted a joint experimental and theoretical study on the structures of [TaO3(CO2)(n)](+) (n = 2-5) ion-molecule complexes in the gas phase. Infrared photodissociation spectra of selected complexes were compared with simulated spectra derived from quantum calculations. The results showed that larger clusters exhibited enhanced fragmentation efficiency and a strong band near the free CO2 antisymmetric stretching vibration, indicating minimal perturbation of CO2 molecules on the secondary solvation sphere. A core structure [TaO3(CO2)(3)](+) was identified, with subsequent CO2 ligands weakly attached.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Jia Han, Pengcheng Liu, Binglin Qiu, Guanjun Wang, Shilin Liu, Xiaoguo Zhou
Summary: This study investigates the mechanism of carbon dioxide activation using infrared spectroscopy and quantum chemical calculations, with tantalum metal cations as a representative. The results show that the tantalum ions insert into the C-O bonds of CO2, forming oxocarbonyl products. Potential energy surface analysis reveals the pivotal role of two-state reactivity in driving CO2 activation.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Yuhui Li, Xinlang Yang, Yuanqin Yu, Xiaoguo Zhou, Rui Zhang, Jin Sun, Shilin Liu
Summary: In this study, the dependence of intramolecular hydrogen bonds on the backbone chain length was demonstrated using linear aminoalcohols as a model system. It was found that the most favorable chain length for intramolecular hydrogen bond formation at room temperature is 3. These findings provide new insights into the nature of intramolecular hydrogen bonds and their potential applications in rational drug design and supramolecular assembly.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
