Article
Chemistry, Physical
Yan-Lin Fu, Yuyao Bai, Yong-Chang Han, Bina Fu, Dong H. Zhang
Summary: The computational results reveal that the double-roaming pathways dominate the total cross section of the H-2 + C2H products at the collision energy of 70 kcal/mol, providing valuable insights into the chemical reaction dynamics and the experimental search for roaming dynamics in this bimolecular reaction.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Multidisciplinary Sciences
Casey D. Foley, Changjian Xie, Hua Guo, Arthur G. Suits
Summary: This study provides evidence of quantum dynamics in the photodissociation of formaldehyde, demonstrating the modulation effect of the roaming pathway on complex vibrational dynamics and coupling among the three dissociation pathways in the excited molecule. Resonances associated with H+HCO(K-a = 1) have a significant impact on CO rotational and translational energy distributions, causing the roaming fraction to vary by a factor of 2 over an energy range of 10 cm(-1).
Article
Chemistry, Physical
Casey D. Foley, Changjian Xie, Hua Guo, Arthur G. Suits
Summary: The unimolecular dissociation of formaldehyde is studied, revealing quantum effects and interactions among radical, molecular, and roaming pathways. The correlation between rotational and vibrational distributions and the mechanism of enhanced roaming are investigated.
FARADAY DISCUSSIONS
(2022)
Article
Chemistry, Physical
Marta Queizan, Sara Gil-Guerrero, Alvaro Perez-Barcia, Jose M. Hermida-Ramon
Summary: Multiconfigurational methods were used to analyze the mechanism of gas-phase phototautomerization of 2-pyridone/2-hydroxypyridine. The results show that tautomerization only occurs after electronic excitation to S1 state, followed by a conical intersection and a roaming process for hydrogen atom migration. The findings provide new insights into the photophysics and photochemistry of a prebiotic model found in interstellar clouds.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Tianlin Liu, Sarah N. Elliott, Meijun Zou, Michael F. Vansco, Christopher A. Sojdak, Charles R. Markus, Raybel Almeida, Kendrew Au, Leonid Sheps, David L. Osborn, Frank A. F. Winiberg, Carl J. Percival, Craig A. Taatjes, Rebecca L. Caravan, Stephen J. Klippenstein, Marsha I. Lester
Summary: Alkene ozonolysis can produce Criegee intermediates, which are important sources of hydroxyl radicals. This study shows that the roaming of separating hydroxyl radicals can result in the formation of alternate hydroxycarbonyl products, leading to a reduction in the yield of hydroxyl radicals. Experimental and theoretical analyses demonstrate that hydroxybutanone is a stable product formed from the roaming of the methyl-ethyl-substituted Criegee intermediate (MECI), and the dynamics of the multistage dissociation process have been investigated.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Tianlin Liu, Sarah N. Elliott, Meijun Zou, Michael F. Vansco, Christopher A. Sojdak, Charles R. Markus, Raybel Almeida, Kendrew Au, Leonid Sheps, David L. Osborn, Frank A. F. Winiberg, Carl J. Percival, Craig A. Taatjes, Rebecca L. Caravan, Stephen J. Klippenstein, Marsha I. Lester
Summary: Alkene ozonolysis generates short-lived Criegee intermediates, which are a significant source of hydroxyl radicals. This study demonstrates that roaming of the separating OH radicals can yield alternate hydroxycarbonyl products, thereby reducing the OH yield. Specifically, hydroxybutanone has been detected as a stable product arising from roaming in the unimolecular decay of certain Criegee intermediates. The mechanism of hydroxybutanone formation has been investigated through theoretical calculations and experimental methods.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
H. da Silva, B. K. Kendrick, N. Balakrishnan
Summary: Quantum calculations are reported for the stereodynamic control of the H + D-2 <-> D + HD chemical reaction in the energy range of 1-50 K. The results show significant control over the reaction by selectively preparing the molecular state, including the possibility of turning the reaction completely on or off.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Veterinary Sciences
M. J. Evans, A. Gibson, H. Fielding, P. Ohal, P. Pandey, A. Kumar, S. K. Singh, I Airikkala-Otter, B. Abela-Ridder, L. Gamble, I Handel, B. M. D. C. Bronsvoort, R. J. Mellanby, S. Mazeri
Summary: The study reveals high rates of loss among neutered dogs in the free-roaming dog population in India, and a modest decline in overall population size over a three-year period. These findings have significant implications for planning rabies vaccination campaigns and population management programs, as well as highlighting the need for further research into the demographics of free-roaming, unowned dogs in India.
RESEARCH IN VETERINARY SCIENCE
(2022)
Article
Multidisciplinary Sciences
Eun Hyuk Choi, Jong Goo Kim, Jungmin Kim, Hosung Ki, Yunbeom Lee, Seonggon Lee, Kihwan Yoon, Joonghan Kim, Jeongho Kim, Hyotcherl Ihee
Summary: Roaming reaction is a reaction pathway that yields products in the long-range potential region, explaining the unimolecular dissociation and isomerization of various molecules. This study investigates the structural dynamics during a roaming-mediated isomerization process, visualizing atomic movements following frustrated bond fission.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Rui Liu, Zhiyuan Zhang, Longxiang Yan, Xinrui Yang, Yu Zhu, Peifeng Su, Huajie Song, Zhigang Wang
Summary: This study reports the roaming process of nitrobenzene influenced by hydrogen bonds between nitro- and phenyl radicals and water molecules. Notably, despite the influence of the hydrogen bonds on the barrier and reaction rates, the roaming reaction still occurs, providing a new approach to modulate the roaming reaction by introducing environmental molecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Jyoti S. Campbell, Klaas Nauta, Christopher S. Hansen, Scott H. Kable
Summary: A new technique for determining absolute photodissociation quantum yields in a molecular beam is reported. The technique utilizes two available product channels in a molecule and directly measures the relative product yield of each channel without the need for external calibration. The technique is demonstrated using the photochemistry of HCHO and yields results consistent with established quantum yields.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Yonghao Mi, Enliang Wang, Zack Dube, Tian Wang, A. Y. Naumov, D. M. Villeneuve, P. B. Corkum, Andre Staudte
Summary: Using near-infrared, femtosecond laser pulses and coincidence momentum imaging, it is found that the dominant channel after photoionization of a deuterium molecular dimer (D-2-D-2) is the ejection of a deuterium atom within a few hundred femtoseconds, leading to the formation of D-3(+). This pathway of D-3(+) formation from ultracold D-2-D-2 gas may provide insights into the high abundance of H-3(+) in the interstellar medium.
Article
Chemistry, Analytical
Benjamin J. Burris, Leah C. Walsh, Abraham K. Badu-Tawiah
Summary: This study describes a contained-electrospray experiment that has the potential to integrate peptide/protein cross-linking with general mass spectrometry workflow. By optimizing the online cross-linking process, various cross-linked products can be detected and it is found that the terminal fully cross-linked product consists of two distinct conformations. This research provides a foundation for future development of high-throughput structural mass spectrometry methods.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Benjamin J. Burris, Leah C. Walsh, Abraham K. Badu-Tawiah
Summary: In this study, the authors developed a contained-electrospray experiment that allows for the integration of peptide/protein cross-linking with mass spectrometry analysis. They optimized the online cross-linking process and identified the different reaction events involved in the crosslinking process. They also observed two distinct conformations of the fully cross-linked product. These findings lay the foundation for future development of a high-throughput structural mass spectrometry method.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Chung-Hsin Yang, Surjendu Bhattacharyya, Kopin Liu
Summary: The photodissociation of acetaldehyde by UV excitation involves multiple reaction pathways, and recent research has focused on disentangling these mechanisms and evaluating branching fractions in specific molecular channels. The study utilized picosecond time-resolved imaging techniques to analyze the competing pathways and provide valuable insights for future research on this interesting system.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)