Article
Biochemistry & Molecular Biology
Evgenii Titov
Summary: The study examines the interactions and electron transition mechanisms of molecules containing azobenzene units in assemblies, finding significant charge transfer contributions under certain conditions. Different methods of partitioning transition density matrix between fragments were evaluated.
Review
Chemistry, Multidisciplinary
Julia Westermayr, Philipp Marquetand
Summary: This review focuses on how machine learning is used to speed up excited-state simulations and advance the research field. Applications of machine learning for excited states include excited-state dynamics simulations, static calculations of absorption spectra, and others.
Article
Chemistry, Multidisciplinary
Shi-Jie Hou, Yi-Fan Yang, Zhong-hua Cui, Lorenz S. Cederbaum
Summary: Anions play an important role in chemistry, but their excited states are generally unstable. This study focused on two promising prototype candidates, Li@C-12 and Li@C-20 anions, and found stable doubly-excited states in addition to stable singly-excited states. The discovery provides insights into designing anions with stable valence singly- and doubly-excited states, and potential applications are mentioned.
Article
Chemistry, Physical
Wenpeng Yuan, Dongyuan Yang, Baihui Feng, Yanjun Min, Zhichao Chen, Shengrui Yu, Guorong Wu, Xueming Yang
Summary: The excited-state decay dynamics of 2-ethylpyrrole following UV excitation in different wavelength ranges were investigated, showing different lifetimes and characteristics for various excited states.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Review
Chemistry, Multidisciplinary
Susanta Mahapatra
Summary: Understanding the structure and dynamics of electronic excited states in molecular systems is essential for various processes, with the coupling of electronic and nuclear motion being a common feature. Pseudo-JT and pseudo-RT coupling can occur in systems with high point group symmetry and orbital degeneracy, requiring the use of quantum chemistry and quantum dynamics methods for study and analysis.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Chemistry, Physical
Tobias Reiker, Zitong Liu, Carsten Winter, Nils Fabian Kleimeier, Deqing Zhang, Helmut Zacharias
Summary: Conjugated polymers based on DPP, combined with different donors, were studied for electronically excited state lifetimes and charge transport properties using time-resolved spectroscopy. After annealing, the ultrafast decay of electrons extended, possibly connected with improved charge transport in the film.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
D. M. P. Holland, D. A. Shaw, D. Townsend, I Powis
Summary: The absolute photoabsorption cross section of imidazole and 1-methylimidazole was measured using synchrotron radiation, and the absorption spectra were analyzed. It was found that the spectra exhibited several broad bands and sharp structures associated with Rydberg states. Assignments were made for some of the observed absorption bands based on calculated transition energies and oscillator strengths, guided by quantum defect analyses. Natural transition orbital plots indicated a mixed Rydberg/valence character for many of the electronically excited states. The irregularities in transition energies and relative intensities of the absorption bands assigned to Rydberg states were attributed to this mixing. Vibrational progressions of some Rydberg states were interpreted using simulations based on the Franck-Condon model.
Article
Chemistry, Multidisciplinary
Denis Leshchev, Andrew J. S. Valentine, Pyosang Kim, Alexis W. Mills, Subhangi Roy, Arnab Chakraborty, Elisa Biasin, Kristoffer Haldrup, Darren J. J. Hsu, Matthew S. Kirschner, Dolev Rimmerman, Matthieu Chollet, J. Michael Glownia, Tim B. van Driel, Felix N. Castellano, Xiaosong Li, Lin X. X. Chen
Summary: The trajectories of photoexcited molecules before thermalization play a crucial role in determining the outcome of photochemical reactions. By using femtosecond wide-angle X-ray solution scattering, the excited-state trajectories of a diplatinum complex with photoactivated metal-metal sigma-bond formation and Pt-Pt stretching motions were observed in real time. The observed motions coincide with the coherent vibrational wavepacket motions detected by femtosecond optical transient absorption. The identification of two key coordinates for intersystem crossing provides insights into the electronic transitions occurring on the time scales of measured vibrational motions, revealing ultrafast nonadiabatic or nonequilibrium processes involving multiple excited-state potential energy surfaces (PESs).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Rui Wei, Shaoying Ju, Liu Leo Liu
Summary: We report a facile and highly modular access to an intriguing class of free Au-substituted phosphines (AuPhos). Au-substitution can boost the electron-releasing ability of AuPhos, leading to an electronically and sterically tunable, extremely electron-rich phosphorus center. Multi-nuclear transition metal complexes ligated by AuPhos are readily prepared, and preliminary catalytic results show the facilitation of C-N coupling reactions and decarbonylation reactions. This work provides insights for future development of electron-rich ligands.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Physics, Multidisciplinary
Junyu He, Junyu Lin, Romain Vexiau, Nadia Bouloufa-Maafa, Olivier Dulieu, Dajun Wang
Summary: The study investigates the lowest ro-vibrational level of the b (3)pi state using high resolution laser spectroscopy with an ultracold sample of (NaRb)-Na-23-Rb-87 molecules. Direct measurement of transition strength and determination of total excited-state spontaneous emission rate are conducted, revealing the dominant role of leakage to the continuum of the a (3)sigma(+) state in the total transition linewidth. Based on these findings, the feasibility of creating optical trapping potentials for maximizing rotational coherence with laser light tuned close to the transition is demonstrated.
NEW JOURNAL OF PHYSICS
(2021)
Article
Chemistry, Physical
Jia Wang, N. Fabian Kleimeier, Rebecca N. Johnson, Samer Gozem, Matthew J. Abplanalp, Andrew M. Turner, Joshua H. Marks, Ralf Kaiser
Summary: Pericyclic reactions have been crucial in advancing our understanding of cycloadditions, sigmatropic shifts, group transfer reactions, and electrocyclization reactions. However, the mechanisms of photochemically activated cheletropic reactions have been a topic of debate. This study reports on the simplest cheletropic reaction and provides evidence for the reaction pathways involved in the addition of O-18 carbon monoxide to photoexcited acetylene. The results demonstrate the power of combining experimental photolysis with theoretical calculations to unravel complex polyatomic reactions at the molecular level.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Spectroscopy
Shu-Yu Lin, Sheng-Lung Chou, Chien-Ming Tseng, Yu-Jong Wu
Summary: We use electron bombardment to generate various silicon hydrides in an Ar matrix containing SiH4. The decomposition of SiH2 and dibridged Si2H2 in solid Ar under 365 nm irradiation is identified through infrared spectroscopy. Corresponding ultraviolet absorption spectra are recorded at each experimental stage. An intense band observed at 170-203 nm, assigned to the C 1B2 & LARR; X 1A1 transition of SiH2, is largely destroyed upon 365-nm photolysis. Moreover, a moderate band observed at 217-236 nm, assigned to the 3 1B2 & LARR; X 1A1 transition of dibridged Si2H2, is slightly reduced. These assignments are based on observed photolytic behavior, as well as the prediction of vertical excitation energies using time-dependent density functional theory and equation-of-motion coupled cluster theory.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Chemistry, Multidisciplinary
Omar K. Farha, Xingjie Wang, Haomiao Xie, Julia G. Knapp, Megan C. Wasson, Yufang Wu, Kaikai Ma, Aaron E. B. S. Stone, Matthew D. Krzyaniak, Yijing Chen, Xuan Zhang, Justin M. Notestein, Michael R. Wasielewski
Summary: Ceria-based materials are highly desirable in photocatalytic reactions due to their redox properties and oxygen storage ability. In this study, CeCe70 and MCe70 clusters (M = Cu, Ni, Co, and Fe) were structurally characterized and found to exhibit enhanced reactivity and improved aldehyde selectivity. Mechanistic studies revealed the importance of oxygen defects and specific transition metal introduction for efficient photocatalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Sara Fiori, Deepak Dagur, Michele Capra, Andrea Picone, Alberto Brambilla, Piero Torelli, Giancarlo Panaccione, Giovanni Vinai
Summary: In the past decade, reducing the dimensionality of materials to few atomic layers has allowed the exploration of new physical properties and functionalities absent in two dimensions. Interfaces and interlayers have been found to play a crucial role in this regime. This study investigates the influence of interfaces and interlayers on the electronic properties and structural quality of ultrathin Cr2O3 films on Pt(1 1 1) in the presence of a multidomain graphene intralayer. The results show that the ultrathin Cr2O3 films are slightly affected by the interfacial epitaxial quality from an electronic point of view, making them potential candidates for graphene-integrated heterostructures.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Rachel Clune, Jacqueline A. R. Shea, Tarini S. Hardikar, Harrison Tuckman, Eric Neuscamman
Summary: We investigate the performance of ESMP2, a recently introduced N-5-scaling excited-state-specific second order perturbation theory, on singlet excitations using the Thiel benchmarking set. We find that ESMP2 is sensitive to p system size without regularization, performing well in small p systems but poorly in large p systems. However, with regularization, ESMP2 becomes less sensitive to p system size and exhibits higher accuracy compared to other methods.
JOURNAL OF CHEMICAL PHYSICS
(2023)
