Journal ArticleDOI
Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer.
TLDR
This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated.Abstract:
The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and “HJ” aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate ...read more
Citations
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Journal ArticleDOI
Aggregation-Induced Emission (AIE): A Historical Perspective.
TL;DR: This Essay discusses the AIE phenomenon from a broader perspective, with an emphasis on early observations related to AIE made long before the term was coined, with a focus on cyanine dyes such as thiazole orange or its dimers.
Journal ArticleDOI
Non-adiabatic Excited-State Molecular Dynamics: Theory and Applications for Modeling Photophysics in Extended Molecular Materials.
Tammie Nelson,Alexander J. White,Josiah A. Bjorgaard,Andrew E. Sifain,Andrew E. Sifain,Yu Zhang,Benjamin Nebgen,Sebastian Fernandez-Alberti,Dmitry Mozyrsky,Adrian E. Roitberg,Sergei Tretiak +10 more
TL;DR: This Review will describe recent theoretical advances including treatment of electronic decoherence in surface-hopping methods, the role of solvent effects, trivial unavoided crossings, analysis of data based on transition densities, and efficient computational implementations of these numerical methods.
Journal ArticleDOI
Machine Learning for Electronically Excited States of Molecules.
TL;DR: In this article, a review of machine learning for excited states of molecules is presented, focusing on not only how machine learning is employed to speed up such excited-state simulations but also how this branch of artificial intelligence can be used to advance this exciting research field in all its aspects.
Journal ArticleDOI
Charge Separation from an Intra-Moiety Intermediate State in the High-Performance PM6:Y6 Organic Photovoltaic Blend
TL;DR: It is reported that the hole transfer channel of photocharge generation is mediated by an intra-moiety excited state in a blend of donor polymer PM6 and NFA Y6 using broadband transient absorption (TA) spectroscopy, suggesting that manipulating the interplay between intra-Moiety and interfacial excited species can provide a promising route for further improving device performance.
Journal ArticleDOI
Molecular polaritons for controlling chemistry with quantum optics
TL;DR: The basic physical principles and consequences of strong light-matter coupling common to molecular ensembles embedded in UV-visible or infrared cavities are described and the competition between the collective cooperative dipolar response of a molecular ensemble and local dynamical processes that molecules typically undergo are discussed.
References
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Journal ArticleDOI
Theory of optical transitions in π-conjugated macrocycles
TL;DR: It is shown how broken symmetry and the Herzberg-Teller effect explain the spectral features of conformationally disordered linear polymers and macrocycles in the limit of sufficiently large disorder, because in both cases they are determined by the optical properties of curved chromophores.
Journal ArticleDOI
Davydov splitting in the sexithiophene crystal
Piotr Petelenz,Marcin Andrzejak +1 more
TL;DR: In this paper, the authors analyzed the discrepancy between the literature value of the level splitting calculated by ZINDO method for sexithiophene clusters and the Davydov splitting calculated for the three-dimensional crystal of α-sexithyphene in the dipole approximation with the transition moment distributed over the six rings.
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Lowest singlet exciton in pentacene: modern calculations versus classic experiments
Barbara Pac,Piotr Petelenz +1 more
TL;DR: Based on simple model calculations, the expected magnitude of the field-induced shift observable in electroabsorption is estimated for three alternative assignments proposed in the literature for the lowest singlet excitation of the pentacene crystal (pure Frenkel exciton, pure charge-transfer exciton or a mixture of both).
Journal ArticleDOI
Defining Cyclic-Acyclic Exciton Transition at the Single-Molecule Level: Size-Dependent Conformational Heterogeneity and Exciton Delocalization in Ethynylene-Bridged Cyclic Oligothiophenes.
Kyu Hyung Park,Jae Won Cho,Tae Woo Kim,Hideyuki Shimizu,Kazumi Nakao,Masahiko Iyoda,Dongho Kim +6 more
TL;DR: This work studied the effect of conformational disorder on the excitonic behaviors of cyclic oligothiophenes composed of 6, 8, 10, and 12 subunits by employing single-molecule fluorescence spectroscopy and found that, due to the cyclic symmetry constraint which suppresses S1-S0 transition, small and rigid C-6T and C-8T exhibit extremely long fluorescence lifetimes, while short lifetimes typical of linear systems are dominant in
Journal ArticleDOI
Ultrafast exciton migration in an HJ-aggregate: Potential surfaces and quantum dynamics
TL;DR: In this article, Binder et al. used the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method to investigate ultrafast dynamics of exciton transfer in a small, asymmetric HJ aggregate model composed of 30 sites and 30 active modes.