Article
Chemistry, Multidisciplinary
Jeffrey T. DuBose, Andrew Christy, Jishnudas Chakkamalayath, Prashant V. Kamat
Summary: The competition between energy transfer and charge trapping in 2D halide perovskite is studied, and sensitized emission is observed in bromide-rich compositions. Broad emission from trap states is observed at low temperatures.
Article
Chemistry, Multidisciplinary
Sapna Ahuja, Sruthy Baburaj, Lakshmy Kannadi Valloli, Sarvar Aminovich Rakhimov, Kavyasree Manal, Aakrati Kushwaha, Steffen Jockusch, Malcolm D. E. Forbes, Jayaraman Sivaguru
Summary: Aryl-maleimides undergo a novel [2+4]-photodimerization instead of the expected [2+2]-photodimerization, and the stereochemistry of the photodimer formed complements the product observed under thermal conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Aparna Shukla, Vikas Kumar Jha, Soumit Chatterjee
Summary: 5-(tert-Butyl)-2-hydroxy-1,3-isophthalaldehyde (5-tBHI) exhibits solvent-dependent single or dual emission. The photophysics of 5-tBHI were investigated in different solvents, and compared with the methyl derivative of the probe and the 5-tBHI anion. The results showed that in non-polar solvents, 5-tBHI mainly adopts an intramolecular H-bonded conformer and undergoes excited state intramolecular proton transfer (ESIPT). However, a dynamic equilibrium was observed in polar, protic solvents, except for water. The proton transfer process, whether intramolecular or intermolecular, was found to occur within 1 picosecond.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Cheng Giuseppe Chen, Mauro Giustini, Marco D'Abramo, Andrea Amadei
Summary: In this paper, the dynamics of the emitting electronic excited state of aqueous indole were reconstructed, and its relaxation mechanism and kinetics were investigated with respect to the time-dependent fluorescence signal. Using recent results, the relaxation process in solution was modeled by transitions between two gas-phase singlet electronic states (L-1(a) and L-1(b)), which subsequently irreversibly relaxed to the gas-phase singlet dark state ((1)pi sigma*). A comparison with experimental data showed that the theoretical-computational model accurately reproduced all experimental observables.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Review
Chemistry, Multidisciplinary
Christophe Jouvet, Mitsuhiko Miyazaki, Masaaki Fujii
Summary: Excited State Hydrogen Transfer (ESHT) is a new paradigm proposed in the late 20th century, which has become important in understanding excited state dynamics of aromatic molecules and re-defining photoinduced proton-transfer reactions. ESHT is also discussed in relation to photo-protection mechanisms of biomolecules such as DNA.
Article
Chemistry, Physical
Chun-Hao Huang, Chi-Chi Wu, Elise Y. Li, Pi-Tai Chou
Summary: In this study, we investigate the deactivating pathways of organic thione containing systems using first-principles calculations. We focus on the S-2 state, which has a large energy difference from the lowest lying S-1 state in sulfur-containing systems. By exploring various theoretical models and molecular designs, we find that thione derivatives can be engineered to possess a high S-2-S-1 energy gap as high as 2 eV, leading to S-2 fission to triplet excitons in the red to near infrared region.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Jacek Dobkowski, Michal Kijak, Sylwester Gawinkowski, Elena Karpiuk, Mariusz Pietrzak, Igor Sazanovich, Jacek Waluk
Summary: 2,5-Bis(6-methyl-2-benzoxazolyl)phenol demonstrates different photophysical properties in different environments, with distinct emission behavior observed for ultracold isolated molecules and solutions. Through experimental and theoretical studies, the inversion of the two lowest singlet states along the proton transfer coordinate is proposed as the explanation for this behavioral difference.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Davide Accomasso, Serra Arslancan, Lorenzo Cupellini, Giovanni Granucci, Benedetta Mennucci
Summary: Carotenoids, as natural pigments, play multiple important roles in photosynthesis, and their structure and photophysical properties play a key role in their functions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Li Zhao, Xuehui Geng, Guoxia Han, Yahui Guo, Runze Liu, Junsheng Chen
Summary: This study investigates the excited state decay mechanism of cytidine in both gas phase and aqueous solution using high-level electronic structure calculations and non-adiabatic dynamic simulations. It is found that cytidine undergoes barrierless decay driven by ring-puckering motion and relaxation channel with a small energy barrier driven by elongation motion of C=O bond. The presence of water molecules significantly reduces the energy barrier, suggesting that the long-lived decay channel in aqueous solution is likely attributed to the cytidine-water intermolecular hydrogen/proton transfer process. These findings contribute to a better understanding of the photostability of DNAs and RNAs and resolve the debate on the cytidine excited-state decay mechanism.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Applied
Qian Zhou, Huitian Du, Zhen Chen, Yuan Yu, Junfeng Ren, Shenghao Han, Jihui Fan, Zhiyong Pang
Summary: This study successfully prepared cocrystals of acridine and 1,2,4,5-tetracyano-benzene by self-assembly, showing novel luminescent properties. The findings may have important implications for the design and applications of nonlinear optical materials.
Review
Chemistry, Physical
Meng Zhou, Rongchao Jin
Summary: This review summarizes recent progress in the excited-state dynamics of atomically precise gold nanoclusters, discussing their electronic structure, relaxation pathways, and dynamics dependent on size, shape, structure, and composition. Quantum confinement effects, size dependence in exciton and electron dynamics, and the role of coherent oscillations in excited-state relaxation are also explored. The review provides insights into future directions in this area.
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, VOL 72
(2021)
Article
Chemistry, Multidisciplinary
Jia-Rui Wu, Dongxia Li, Gengxin Wu, Meng-Hao Li, Ying-Wei Yang
Summary: This study develops a strategy to modulate supramolecular ICT interactions in the solid state by compressing the binding cavity of a macrocyclic host, leading to improved affinities with electron-deficient planar guests.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Shun-Cheung Cheng, Shing-Lun Chan, David Lee Phillips, Chi-Chiu Ko
Summary: The excited-state dynamics of cyanide-bridged trinuclear carbonyl rhenium(I) complexes and their monomeric peripheral control complexes have been investigated using ultrafast transient absorption spectroscopy. The emissive excited states and absorption transient were characterized using nanosecond transient Raman spectroscopy.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Leila Shahrokh, Reza Omidyan, Gholamhassan Azimi
Summary: The study utilizes ab initio and surface-hopping nonadiabatic dynamics simulation methods to investigate relaxation mechanisms in protonated thymine (TH+) and cytosine (CH+). Multiple conical intersections were located between (1)pi pi* and S-0 states for each system, with particular focus on the barrier-free out-of-plane deformation governing relaxation from the (1)pi pi* state to the ground state. The ring puckering coordinate from the C-6 position of the heterocycle ring was found to play a prominent role in the deactivation mechanism of the considered systems, supported by excited-state nonadiabatic dynamics simulations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Xiuxing Liu, Qiuyan Liao, Jie Yang, Zhen Li, Qianqian Li
Summary: The phosphorescence of organic materials is influenced by intermolecular interactions, which are affected by various factors and uncontrollable aggregated behaviors. By controlling the temperature, the afterglow can change colors continuously, achieving white emission with deuteration. This is due to the hierarchical architectures of molecular aggregates and the unlocking process of interactions with different energies. Establishing the correspondence between interactions and excited triplet states allows for accurate design of desirable phosphorescence materials through hierarchical control of aggregated structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jonas Weiser, Jingjing Cui, Rian D. Dewhurst, Holger Braunschweig, Bernd Engels, Felipe Fantuzzi
Summary: This study computationally investigates the properties of group 13-15 homodimers stabilized by a rigid expanded pincer ligand based on the 1,8-naphthyridine core. The results demonstrate the versatility of the ligand in generating various structural motifs and element-element interaction modes, suggesting potential applications in synthetic chemistry.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sven E. Prey, Christoph Herok, Felipe Fantuzzi, Michael Bolte, Hans-Wolfram Lerner, Bernd Engels, Matthias Wagner
Summary: Alkali-metal salts of 9,10-dimethyl-9,10-dihydro-9,10-diboraanthrancene can activate the H-B bond of pinacolborane at room temperature, leading to the formation of new bonding products. Depending on the alkali metal used, the products can contain new H-B and B-Bpin bonds. The Li+ salt results in the transfer of the H- ion to another pinacolborane molecule to form Li[5]. This Li[5] compound donates a [Bpin](+) cation to Li[SiPh3] to generate Ph3Si-Bpin, while Li-2[DBA-Me-2] acts as a leaving group. Moreover, Li-2[DBA-Me-2] can catalyze the hydroboration of various unsaturated substrates in THF, with different reaction mechanisms observed depending on the steric demands of the substrate.
Article
Chemistry, Multidisciplinary
Fangyuan Zhang, Florian Rauch, Asim Swain, Todd B. Marder, Prince Ravat
Summary: This article introduces a design strategy to achieve narrow-band emission for applicable circularly polarized luminescence (CPL) active materials in ultrahigh-definition CP-OLEDs, by exploiting intramolecular donor-acceptor interactions between nitrogen and boron atoms. Single- and double-helicenes with 1,4-B,N-embedded configurationally stable structure were successfully synthesized, showing unprecedentedly narrow fluorescence and CPL bands, along with high fluorescence quantum yields.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hamad H. Al Mamari, Julie Borel, Aobha Hickey, Eimear Courtney, Julia Merz, Xiaolei Zhang, Alexandra Friedrich, Todd B. Marder, Gerard P. McGlacken
Summary: The quinolone-quinoline tautomerization is utilized to achieve regioselective C8-borylation of biologically important 4-quinolones. This is done by using [Ir(OMe)(cod)](2) as the catalyst precursor, the silica-supported monodentate phosphine Si-SMAP as the ligand, and B(2)pin(2) as the boron source. The resulting C8-borylated quinolines can be further converted to various derivatives with different substituents.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Zhu Wu, Nikolai Hippchen, Jie Han, Lei Ji, Alexandra Friedrich, Ivo Krummenacher, Holger Braunschweig, Johannes Krebs, Michael Moos, Philipp Biegger, Olena Tverskoy, Steffen Maier, Christoph Lambert, Andreas Dreuw, Todd B. Marder, Jan Freudenberg, Uwe H. F. Bunz
Summary: This study presents the reduction of two azaacenes to their radical anions and dianions, leading to increased antiaromaticity and red-shifted absorption spectra. Crystal structures of the reduced species were obtained and their optoelectronic properties were evaluated. The reduction was achieved using potassium naphthalenide in the presence of 18-crown-6 in THF.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Lukas Tendera, Laura Kuehn, Todd B. Marder, Udo Radius
Summary: The synthesis of the first terminal mono-boryl complexes of nickel, without a pincer ligand, is reported. Various reactions were conducted to exchange ligands and obtain the desired nickel mono-boryl complexes.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Sara Wirsing, Marc Haensel, Luca Craciunescu, Valentina Belova, Frank Schreiber, Katharina Broch, Bernd Engels, Petra Tegeder
Summary: By combining femtosecond time-resolved second harmonic generation (SHG) with large scale quantum chemical calculations, we studied the ultrafast excited state dynamics at interfaces between diindenoperylene (DIP) and dicyano-perylene-bis(dicarboximide) (PDIR-CN2). Our results showed that an optically induced charge transfer (CT) is observed in the configuration with edge-on geometry and additional face-on domains, resulting in an increase in SHG signal intensity. The interfacial CT state decays within 7.5±0.7 ps, while the creation of hot CT states leads to a faster decay (5.3±0.2 ps). The formation of interfacial CT is suppressed in bilayer structures with mainly edge-on geometries due to the lack of π-π overlap perpendicular to the interface. Our study provides important insights into the D/A charge transfer properties and the interfacial photophysics of these molecules.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Correction
Chemistry, Multidisciplinary
Avijit Maiti, Fangyuan Zhang, Ivo Krummenacher, Moulika Bhattacharyya, Sakshi Mehta, Michael Moos, Christoph Lambert, Bernd Engels, Abhishake Mondal, Holger Braunschweig, Prince Ravat, Anukul Jana
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Maximilian Dietz, Merle Arrowsmith, Lukas Endres, Valerie Paprocki, Bernd Engels, Holger Braunschweig
Summary: A study found that stable pogo-stick complexes can be synthesized through a series of reactions, and their characteristics were confirmed by infrared spectroscopy and X-ray crystallography. These complexes exhibited strong absorption in the near-infrared region. Theoretical calculations further elucidated the mechanism of these absorptions. Additionally, the complexes can react with other compounds to form new substances.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Jiefeng Hu, Man Tang, Jing Wang, Zhu Wu, Alexandra Friedrich, Todd B. Marder
Summary: We report the design and synthesis of a stable, multifunctional (diborylmethyl)iodide reagent for the photoinduced cyclopropanation of alkenes, providing an array of 1,2-substituted cyclopropylboronates in good yields. The protocol displays high chemo- and diastereoselectivity, excellent functional-group tolerance, and allows for late-stage borylcyclopropanation of complex molecules. Mechanistic studies reveal that the borylcyclopropanation proceeds through a radical addition/polar cyclization pathway mediated by the photocatalyst fac-Ir(ppy)(3) and visible light.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Julian Hausch, Nico Hofeditz, Jona Bredehoeft, Sebastian Hammer, Jens Pflaum, Katharina Broch, Marina Gerhard, Frank Schreiber
Summary: The coherent distribution of an electronic excitation over multiple organic molecules in the solid state, known as excited-state delocalization, plays a crucial role in processes like singlet fission. However, experiments studying the influence of excited-state delocalization on singlet fission have been challenging due to the difficulty of measuring it and accessing the optically dark triplet-pair state, which is an important intermediate in singlet fission. By altering the growth conditions, researchers demonstrate that the emission from the triplet-pair state is observable in films with low growth rates of the singlet fission material, indicating a correlation between luminescence and higher excited-state delocalization.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Maximilian Ochs, Laurent Jucker, Maximilian Roedel, Monika Emmerling, Rene Kullock, Jens Pflaum, Marcel Mayor, Bert Hecht
Summary: By utilizing selective self-assembled monolayers, we demonstrate site-selective functionalization of laterally arranged micro- and nanoelectrodes, leading to optimized electronic interface properties and improved development of efficient nanolight sources.
Article
Chemistry, Physical
Jeswin Sunny, Ebin Sebastian, Suvarna Sujilkumar, Frank Wuerthner, Bernd Engels, Mahesh Hariharan
Summary: This study reports the unprecedented population of triplet excited states in a series of nitrogen-annulated perylene bisimide chromophores. Ultrafast intersystem crossing is found in Br-NPBI, leading to enhanced triplet population. The quantum chemical calculations reveal the important role of nitrogen annulation in tuning the excited state energy levels to favor intersystem crossing.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Christos Gatsios, Andreas Opitz, Dominique Lungwitz, Ahmed E. Mansour, Thorsten Schultz, Dongguen Shin, Sebastian Hammer, Jens Pflaum, Yadong Zhang, Stephen Barlow, Seth R. Marder, Norbert Koch
Summary: Surface molecular doping of organic semiconductors is crucial in the development of organic electronic or optoelectronic devices. This study reveals that surface molecular doping can effectively control the Fermi level position of rubrene single crystals while maintaining good charge-carrier mobility.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)