Article
Chemistry, Physical
Renata Karpicz, Gabriele Kareivaite, Mindaugas Macernis, Darius Abramavicius, Leonas Valkunas
Summary: The variability in the spectral properties of solid stilbene conformations under different external conditions is still not clear. The photophysical properties of trans-stilbene solution in solid polystyrene glass were investigated using absorption and time-resolved fluorescence. Concentration-induced quenching was observed at low concentrations, while at high concentrations, the spectroscopic characteristics were split between two phases of the sample. Ab initio and molecular dynamics analyses suggested a permanent twisting of the stilbene molecular structure upon crystallization, supporting the spectroscopic phase separation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Spectroscopy
Yurong Guo, Mengqi Wang, Zibo Wu, Yanan Shi, Ye Wang, Song Zhang, Bing Jin, Shen Cui, Guangjiu Zhao
Summary: In this study, the potential UV protection mechanism of natural compounds hydroxy resveratrol and pterostilbene was investigated using theoretical calculations and femtosecond transient absorption spectra (FTAS). The UV absorption spectra showed that these compounds had strong absorption properties and were highly photostable. The results revealed that both molecules reached the S-1 state or higher excited states after UV exposure, and underwent adiabatic trans-cis isomerization process before returning to the ground state. Furthermore, the FTAS data indicated that the trans-cis isomerization of these molecules occurred within a time scale of about 10 ps, suggesting fast energy relaxation. This work provides theoretical guidance for the development of new sunscreen molecules from natural stilbene.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Optics
Guanhua Ren, Lu Zhou, Ligang Chen, Liyuan Liu, Jianbing Zhang, Hongwei Zhao, Jiaguang Han
Summary: Terahertz spectroscopy serves as a powerful tool for monitoring crystallization and isomerization processes of molecules, with results showing the formation of a new phase is dependent on cooling rate and investigation of thermal- and photo-induced isomerization processes based on distinctive spectral features of isomers.
Article
Chemistry, Physical
Ronaldo C. Amaral, Lais S. Matos, Neyde Y. Murakami Iha
Summary: The photochemical and photophysical behaviors of fac-[Re(CO)3(R2bpy)(trans-bpe)]+ complexes were studied, showing a remarkable and efficient sensitization of trans-cis photoisomerization. The complexes exhibited higher trans-to-cis photochemical quantum yields compared to non-coordinated ligands. As cis-isomers formed, a growing emission of 3MLCTRe -> R2bpy was observed, with no reverse cis-> trans photoisomerization process detected under experimental conditions.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Joshua Seylar, Dmytro Stasiouk, Davide L. Simone, Vikas Varshney, James E. Heckler, Ruel McKenzie
Summary: TEMPO was found to be more suitable for the photocyclization of stilbene compared to iodine, resulting in higher yields of phenanthrene in shorter times and reduced undesired [2+2] cycloadditions. Iodine was shown to retard phenanthrene formation by promoting isomerization to (E)-stilbene, which in turn encouraged [2+2] cycloaddition reactions.
Article
Chemistry, Multidisciplinary
Chuncheng Wang, Max D. J. Waters, Pengju Zhang, Jiri Suchan, Vit Svoboda, Tran Trung Luu, Conaill Perry, Zhong Yin, Petr Slavicek, Hans Jakob Worner
Summary: This study contrasts the excited-state dynamics in gas and liquid phases using extreme-ultraviolet time-resolved photoelectron spectroscopy, revealing the influence of liquid environment on electronic and structural dynamics during a photochemical transformation.
Article
Chemistry, Physical
Laura M. Obloy, Patrick Z. El-Khoury, Alexander N. Tarnovsky
Summary: The excited-state dynamics of trans-4,4'-azopyridine in ethanol were investigated using femtosecond transient absorption. Vibrational coherence was observed in both S1 n pi* and S2 pi pi* electronic states. The relaxation pathway showed nonrotational behavior, with population being trapped in planar and shallow minima before decaying into the ground state. Nonrotational relaxation and the formation of hot ground-state species were observed upon excitation of the S2 state. The cis-isomer quantum yield increased with pi pi* excitation, in contrast to trans-azobenzene.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Suyesh Koyu, Timur V. Tscherbul
Summary: We present a theoretical study of quantum coherent dynamics of a three-level lambda-system driven by a thermal environment. We observe that thermal excitations can generate experimentally observable long-lived quantum coherent dynamics in the absence of coherent driving.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Qianqian Gong, Yazhen Li, Xiaoke Nie, Fengyi Liu
Summary: The multilevel ONIOM framework has been proven to be an efficient tool for understanding the mechanism of aggregation-induced emission (AIE). The ionic styryl-pyridine salt (SPH) has been identified as a new class of AIEgen with high fluorescence yield. Choosing the appropriate QM model (monomer or dimer) is crucial for studying the AIE mechanism of SPH. The dimer model provides increased barriers and a red-shifted emission wavelength, while also revealing the exciton coupling in the fluorescence emission state.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Dmitry V. Makhov, Dmitrii V. Shalashilin
Summary: The research shows that pre-excitation of N-H bond vibrations facilitates fast direct dissociation, resulting in a significant increase in the high-energy wing of TKER spectra. The simulations are in good agreement with recent experimental results, indicating the specificity of this effect for N-H bond vibrations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Umberto Raucci, Hayley Weir, Christoph Bannwarth, David M. Sanchez, Todd J. Martinez
Summary: In this study, the authors used non-adiabatic first principles molecular dynamics to demonstrate the conversion of an achiral molecule to a chiral one upon photoexcitation, highlighting the possibility of asymmetric photochemistry starting from achiral reactants.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Shutaro Karashima, Xincheng Miao, Akio Kanayama, Yo-ichi Yamamoto, Junichi Nishitani, Nikita Kavka, Roland Mitric, Toshinori Suzuki
Summary: In this study, we discovered the ultrafast ring closure reaction of gaseous cis-St for the first time using extreme ultraviolet time-resolved photoelectron spectroscopy. Previous computational simulations predicted a quantum yield of only 0.04 for the formation of 4a,4b-dihydrophenanthrene (DHP) from cis-St, but our results showed a different branching ratio of 0.55:0.41:0.04 for cis-St:DHP:trans-St.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Marco Paolino, Tommaso Giovannini, Madushanka Manathunga, Loredana Latterini, Giulia Zampini, Robin Pierron, Jeremie Leonard, Stefania Fusi, Gianluca Giorgi, Germano Giuliani, Andrea Cappelli, Chiara Cappelli, Massimo Olivucci
Summary: An experimental/computational study of a candidate obtained via the asymmetrization of a light-driven biomimetic molecular switch was conducted. The achieved motor has an ECD band that is remarkably sensitive to isomerization motion, suitable for timeresolved ECD studies. However, the synthesized motor isomerizes on a longer time scale than expected.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Qixin Chen, Xixi Hu, Hua Guo, Daiqian Xie
Summary: A trajectory study of the reaction dynamics on a full-dimensional potential energy surface (PES) reveals that the energy of the highly exoergic reaction H + O-3 -> OH + O-2 is primarily channeled into the vibration of the OH product, deviating significantly from the statistical limit. The calculated highly inverted OH vibrational distribution, peaking near the highest accessible vibrational state, is in excellent agreement with experimental observations, validating the accuracy of the PES. Additionally, the nonthermal excitation of the OH vibrational mode is traced back to a small potential barrier in the entrance channel, controlling the energy flow into various degrees of freedom in the products.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Nuclear Science & Technology
Nguyen Duy Quang, HongJoo Kim, Phan Quoc Vuong, Nguyen Duc Ton, Uk-Won Nam, Won-Kee Park, JongDae Sohn, Young-Jun Choi, SungHwan Kim, SukWon Youn, Sung-Joon Ye
Summary: An overall procedure for measuring and unfolding fast neutron spectra using a trans-stilbene scintillation detector is proposed in this paper. The detector characterization, neutron-gamma Pulse Shape Discrimination (PSD), and fitting technique to increase the trans-stilbene Proton Response Function (PRF) are described. The spectrum unfolding using Monte-Carlo simulation and iterative Bayesian method shows reliable and stable results for simulated and measured neutron sources.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2023)
Article
Polymer Science
Madeleine P. Gordon, Lawson T. Lloyd, David S. Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2016)
Article
Polymer Science
Jason S. Howell, David S. Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2016)
Article
Chemistry, Physical
David Boucher, Jason Howell
JOURNAL OF PHYSICAL CHEMISTRY B
(2016)
Article
Polymer Science
Dillon Presto, Vivian Song, David Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2017)
Article
Polymer Science
David S. Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2017)
Article
Chemistry, Physical
Jason Howell, Miranda Roesing, David Boucher
JOURNAL OF PHYSICAL CHEMISTRY B
(2017)
Article
Polymer Science
Miranda Roesing, Jason Howell, David Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2017)
Article
Polymer Science
Marni Sapolsky, David Boucher
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2018)
Article
Polymer Science
Marni Sapolsky, John McFaddin, David Boucher
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2018)
Article
Computer Science, Information Systems
Kyle M. L. Jones, Andrew Asher, Abigail Goben, Michael R. Perry, Dorothea Salo, Kristin A. Briney, M. Brooke Robertshaw
JOURNAL OF THE ASSOCIATION FOR INFORMATION SCIENCE AND TECHNOLOGY
(2020)
Article
Chemistry, Multidisciplinary
Sunghwan Kim, Ehren C. Bucholtz, Kristin Briney, Andrew P. Cornell, Jordi Cuadros, Kristen D. Fulfer, Tanya Gupta, Evan Hepler-Smith, Dean H. Johnston, Andrew S. I. D. Lang, Delmar Larsen, Ye Li, Leah R. McEwen, Layne A. Morsch, Jennifer L. Muzyka, Robert E. Belford
Summary: The paper introduces the Cheminformatics Online Chemistry Course (OLCC) organized by the Committee on Computers in Chemical Education (CCCE) of the American Chemical Society (ACS)'s Division of Chemical Education (CHED). The collaborative teaching project involves instructors from multiple schools and external chemical information experts recruited from various sectors, aiming to help students acquire skills in handling chemical information and promote cooperation through online discussions.
JOURNAL OF CHEMICAL EDUCATION
(2021)
Article
Information Science & Library Science
Andrew D. Asher, Kristin A. Briney, Kyle M. L. Jones, Mariana Regalado, Michael R. Perry, Abigail Goben, Maura A. Smale, Dorothea Salo
Summary: There are differences in students' views on academic library participation in learning analytics and privacy concerns. Some students lack trust in libraries and librarians, believing that their access to and sharing of personally identifiable information constitutes a privacy violation. However, they also lack awareness of library data and analytic practices.
Article
Information Science & Library Science
Andrew Asher, Kristin Briney, Abigail Goben
Summary: This article describes the development, sampling and analysis practices, and reliability and validity assessment of a new survey on undergraduate students' perceptions and expectations about privacy and library participation in learning analytics studies. It provides researchers with information to evaluate the survey's efficacy and guidance for designing similar surveys.
PERFORMANCE MEASUREMENT AND METRICS
(2023)
Article
Information Science & Library Science
Kyle M. L. Jones, Kristin A. Briney, Abigail Goben, Dorothea Salo, Andrew Asher, Michael R. Perry
COLLEGE & RESEARCH LIBRARIES
(2020)
Meeting Abstract
Chemistry, Multidisciplinary
Kristin Briney, Ye Li, Leah McEwen
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2016)