Article
Chemistry, Multidisciplinary
Kristina Martinez, Sydney M. Koehne, Kaitlyn Benson, Jared J. Paul, Russell H. Schmehl
Summary: Bimolecular excited-state proton-coupled electron transfer (PCET*) was observed for the reaction between the triplet MLCT state of [(dpab)2Ru(4,4 '-dhbpy)]2+ and N-methyl-4,4 '-bipyridinium (MQ+) and N-benzyl-4,4 '-bipyridinium (BMQ+). The PCET* products, oxidized and deprotonated Ru complex, and reduced protonated MQ+ can be distinguished from other reaction products based on the difference in their visible absorption spectra. The observed behavior is different from the reaction between the MLCT state of [(bpy)2Ru(4,4 '-dhbpy)]2+ and MQ+, which involves initial electron transfer (ET*) followed by proton transfer (PT*).
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Xueying Lu, Yongxu Hu, Huapeng Liu, Jiannan Qi, Xiaosong Chen, Yajing Sun, Wenping Hu
Summary: Purely organic fluorescence emitters with ultrahigh exciton utilization, such as thermally-activated delayed fluorescence (TADF) materials, are pursued as the cornerstone of the new-generation organic light-emitting diodes (OLEDs). However, most TADF emitters suffer from the dilemma of the aggregation-caused fluorescence quenching effects, severely limiting their applications. Excitingly, the recently proposed aggregation-induced delayed fluorescence (AIDF) strategy holds the potential to tackle this problem thoroughly. Here, the recently reported AIDF emitters CP-BP-PXZ and its halogenated counterparts, 3-CCP-BP-PXZ and 3-BCP-BP-PXZ, are investigated with a united theoretical and experimental insight. Based on first-principles calculations combined with the polarizable continuum model (PCM) and the quantum mechanics/molecular mechanics (QM/MM) model, the photophysical mechanisms of these novel materials are proposed. It is found that both reverse intersystem crossing (RISC) and the subsequent radiative transition of CP-BP-PXZ are promoted via aggregation, owing to the increased effective RISC channels and boosted oscillator strength. Meanwhile, the unfavorable internal conversion rate is greatly slumped, ascribed to the suppressed Duschinsky rotation effect (DRE). The unique heavy-atom effect is disclosed in 3-CCP-BP-PXZ and 3-BCP-BP-PXZ that the halogens act as steric blockers in crystal, rather than spin-orbit coupling enhancers. It is hoped that this work can shed new light on the designation of high-efficient solid-state fluorescence emitters.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Mathematics, Applied
Arnold Reusken, Benjamin Stamm
Summary: This study focuses on the Schwarz overlapping domain decomposition method applied to a special family of domains for the Poisson problem, analyzing the stable decomposition and its dependence on geometric properties. The research introduces new descriptors to formalize the geometry and shows how the convergence rate of the Schwarz method relates to specific local and global geometry descriptors. Additionally, the analysis provides lower bounds for the smallest eigenvalue of the Laplace eigenvalue problem for this family of domains.
SIAM JOURNAL ON NUMERICAL ANALYSIS
(2021)
Article
Optics
Martin A. Mosquera
Summary: Time-dependent response theories are crucial for determining quantum properties of electronic excited states, and are employed in various methods in incremental order. In this work, a linear response approach is developed to offer transition elements between different excited states, consistent with quadratic response theory. This work also formulates an extension for general propagations under nonlinear external perturbations and establishes a connection with the physics of wave-function theory.
Article
Chemistry, Physical
Xunkun Huang, Zheng Pei, WanZhen Liang
Summary: Nonadiabatic phenomena, characterized by strong coupling between electronic and nuclear motions, are affected by surrounding environment like solvents. It is crucial to develop theoretical models that accurately simulate these processes while modeling the solvent environment. Time-dependent density functional theory (TDDFT) and polarizable continuum model (PCM) are efficient approaches for describing electronic structures and dynamics, respectively. Analytical derivative couplings (DCs) are formulated between ground and excited states, and implemented into the Q-CHEM software. The solvent effect is demonstrated in 4-(N,N-dimethylamino)benzonitrile and uracil examples, showing its impact on excitation energies and DCs between states. The current implementation allows for studying nonadiabatic effects in large systems in solution with low computational cost.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Nuclear Science & Technology
De-Xing Zhu, Yang-Yang Xu, Hong-Ming Liu, Xi-Jun Wu, Biao He, Xiao-Hua Li
Summary: This study systematically investigated the two-proton radioactivity half-lives from the excited state of nuclei near the proton drip line using the Gamow-like model and modified Gamow-like model. The calculated results were highly consistent with theoretical values from other models, and it was found that the half-lives are strongly dependent on Q(2p) and l based on the analysis of the results.
NUCLEAR SCIENCE AND TECHNIQUES
(2022)
Article
Chemistry, Physical
Soumi Haldar, Tamoghna Mukhopadhyay, Achintya Kumar Dutta
Summary: The article presents a novel and cost-effective approach to improve the CC2 model by using a second similarity transformation of the Hamiltonian to include higher-order terms. The newly developed ST-EOM-CC2 model shows significant improvement in excitation energies of Rydberg and charge-transfer excited states while retaining good performance for valence excited states.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Mojtaba Alipour, Tahereh Izadkhast
Summary: Hyperfluorescence has been introduced as a promising strategy to achieve high color purity and enhanced stability in organic light-emitting diodes (OLEDs). In this study, the alignments of excited-states in fluorescent emitters (FEs) were investigated using optimally tuned range-separated hybrid functionals (OT-RSHs). Several models were proposed and validated to accurately describe the excited-states ordering in hyperfluorescence-based materials. The best-performing model was found to be the OT-RSHs-PCM with the correct asymptotic behavior and no (low) short-range Hartree-Fock exchange contribution. This study provides recommended models for theoretical modeling and confirming experimental observations in the field of hyperfluorescence-based OLEDs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Abd-Allah Hyder, Mohamed A. Barakat, Ahmed H. Soliman, Areej A. Almoneef, Clemente Cesarano
Summary: In this paper, the coupled nonlinear KdV equations are solved in a stochastic environment by utilizing Hermite transforms, generalized conformable derivative, and a merging algorithm of white noise instruments and the (G'/G(2))-expansion technique. White noise functional conformable solutions for these equations are obtained. New stochastic periodic and soliton solutions for these equations under conformable generalized derivatives are produced. The obtained solutions exhibit controlled monotonicity and symmetry by assigning a value to the conformable parameter. A comparison between the obtained wave solutions and the wave solutions constructed under the conformable derivatives and Newton's derivatives is presented.
Article
Chemistry, Physical
Zhe Tang, Haiyun Han, Junxia Ding, Panwang Zhou
Summary: This study investigates the impact of upper excited states on double fluorescence using time-dependent density functional theory. A new mechanism for dual fluorescence is proposed, involving different decay pathways from the upper excited state.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Iryna Knysh, Ivan Duchemin, Xavier Blase, Denis Jacquemin
Summary: This study presents a benchmark investigation of excited state potential energy surfaces using various theoretical models, focusing on 4-(dimethylamino)benzonitrile as a paradigmatic system. The results demonstrate that the BSE/GW approach can accurately reproduce the topology of the potential energy surfaces and predict vertical transition energies in good agreement with coupled cluster methods. Additionally, the BSE method is able to accurately describe solvent-induced changes in the excited states.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Zhuojun Liu, Jiayi Wang, Bo Chen, Yuming Wei, Wenjing Liu, Jin Liu
Summary: Two-dimensional layered materials like GaSe have shown promise as novel nonlinear optical materials, but their nonlinear responses are limited by short interaction lengths with light. By coupling 2D GaSe flakes to silicon metasurfaces, a significant enhancement of second-harmonic generation (SHG) has been achieved, opening up new possibilities for high-power coherent light sources.
Article
Mathematics, Applied
Saeed M. Ali, Mohammed S. Abdo, Bhausaheb Sontakke, Kamal Shah, Thabet Abdeljawad
Summary: The paper introduces and analyzes a coupled system of second-order fractional pantograph differential equations with coupled four-point boundary conditions. Through the application of nonlinear alternatives and contraction mapping, the existence and uniqueness of solutions are proven. Additionally, the stability of the solutions is demonstrated using Ulam-Hyers stability theory.
Article
Nanoscience & Nanotechnology
Zhanghua Han, Fei Ding, Yangjian Cai, Uriel Levy
Summary: All-dielectric optical nanoantennas based on high-index semiconductors are proven to be an effective and low-loss alternative to metal-based plasmonic structures for light control and enhancing light-semiconductor interactions. By carefully designing high-index semiconductor nanostructures, novel high-quality factor resonances based on the concept of bound states in the continuum can be easily excited, further boosting nonlinear effects. Using AlGaAs as the nonlinear material, a significant increase in second-harmonic generation efficiency is demonstrated compared to magnetic dipole resonances.
Article
Chemistry, Inorganic & Nuclear
R. Lopez-Esquivel, I. A. Garduno-Wilches, J. C. Guzman-Olguin, T. Rivera Montalvo, J. Guzman-Mendoza
Summary: This study investigates the thermally coupled energy levels of the trivalent europium ion in the barium hafnate matrix using ultraviolet radiation in the temperature range of 289.7-323.8 K. The results show that the sample doped with 3.0% atomic of trivalent europium exhibits the highest luminescent emission, while the bands associated with D-5(0) → F-7(J) (J = 1, 2, 3, 4) transitions have a strong dependence on temperature within the physical range.
APPLIED RADIATION AND ISOTOPES
(2022)