Article
Chemistry, Multidisciplinary
Daniel Matuszczyk, Yu Jin Lee, Seongsoo Kang, Piotr J. Chmielewski, Joanna Cybinska, Dongho Kim, Marcin Stepien
Summary: A series of propeller-shaped donor-acceptor compounds were successfully synthesized via nucleophilic substitution reactions, showing efficient charge transfer especially between ortho-positioned donors and acceptors. This study is of significance for understanding the process of electron transfer.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Zimu Wei, Sushil Sharma, Abbey M. Philip, Sanchita Sengupta, Ferdinand C. Grozema
Summary: Donor-bridge-acceptor systems based on BODIPY show potential for bio-imaging and sensing applications, with their photophysical behavior depending on solvent polarity. Factors such as donor-acceptor distance and restricted rotational motion play key roles in tuning the excited state photophysics.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Joshua J. Sutton, Dan Preston, Philipp Traber, Johannes Steinmetzer, Xue Wu, Surajit Kayal, Xue-Z Sun, James D. Crowley, Michael W. George, Stephan Kupfer, Keith C. Gordon
Summary: The optical properties of two Re(CO)(3)(bpy)Cl complexes with different substituents were studied, revealing distinct charge transfer bands in their absorption spectra and two emissive states in their excited-state spectroscopy which are modulated by solvent. Time-resolved infrared spectroscopy identified the nature of the excited states in different solvents, with DFT calculations suggesting that the switching of properties induced by solvent is controlled by spin-orbit coupling.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Applied
Hongke Zhou, Qian Huang, Xingliang Liu, Defang Xu, Weidong Zhang, Shengjie Fu, Xiucun Feng, Zhan Zhang
Summary: Two donor-acceptor luminophores PTZ-DPS and BPTZ-DPS, designed with phenothiazine and diphenylsulfone units, exhibit twisted molecular conformation, unique intramolecular charge transfer behavior, and intense fluorescence. They show switchable mechanofluorochromism, high solid-state luminescence efficiencies, and large spectral red shifts. The mechanofluorochromic behavior is due to phase transition between crystalline to amorphous states.
Review
Chemistry, Multidisciplinary
Xi Chen, Xue Zhang, Xiao Xiao, Zhijia Wang, Jianzhang Zhao
Summary: Charge transfer is crucial in molecular electron donor-acceptor systems for artificial photosynthesis, photocatalysis, photovoltaics, and fundamental photochemistry. We summarized recent developments in the study of charge transfer and discussed its application in thermally activated delayed fluorescence (TADF) emitters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Shubhankar Barman, Aritri Pal, Anurag Mukherjee, Swadesh Paul, Anuja Datta, Suhrit Ghosh
Summary: This review provides an overview of the research status and future development of organic ferroelectric materials. Among them, donor-acceptor charge transfer complexes are considered promising for ferroelectricity. The review lists different organic systems and molecular assembly forms, and discusses their performances in terms of ferroelectricity and piezoelectricity.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Jumi Park, Jooyoung Sung, Dongho Kim
Summary: In this study, the charge transfer (CT) processes in donor-pyreneacceptor (DPA) molecules were deciphered using various time-resolved spectroscopic measurements. The ultrafast CT rate of approximately 200 fs in DPA molecules was observed, indicating isoenergetic potential surfaces for LE and CT states. Strong electronic coupling between the LE and CT states was found upon the introduction of the acceptor to the pyrene moiety in DPA systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Xin Chang, Mohammad Balooch Qarai, Frank C. Spano
Summary: A vibronic exciton model was developed to explain the spectral signatures of HJ-aggregates in oligomers and polymers with donor-acceptor-donor repeat units. The model shows that single chains with enhanced intrachain order exhibit J-behavior, while positive H-promoting interchain Coulomb interactions in aggregates attenuate the vibronic ratio. The ratio formula derived previously for P3HT aggregates was shown to also apply to (DAD)(N) aggregates with slight modifications.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Lijing Gong, Xiangyu Zhang, Cheng Ma
Summary: Utilizing DFT/TD-DFT theory, this paper investigates the impact of electron-accepting ability of the central core, substituent, and position on the properties of compounds, revealing that replacing the OT unit with an IC unit enhances absorption peak, reduces hole reorganization energy, and improves NLO properties. The studied compounds show potential as hole transport materials and strong second-order nonlinear materials due to their favorable characteristics.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Applied
Shengjie Fu, Yi Tan, Shiai Zhang, Jiayi Lv, Xiucun Feng, Defang Xu, Xingliang Liu
Summary: The study synthesized two fluorescent molecules with high-contrast reversible mechanofluorochromic properties, exhibiting twisted intramolecular charge-transfer states and good solid-state emission properties. Grinding the samples resulted in emission of fluorescence of different colors.
Review
Chemistry, Multidisciplinary
Leendert van Dalsen, Rachel E. Brown, James A. Rossi-Ashton, David J. Procter
Summary: The photoactivation of electron donor-acceptor complexes is a sustainable and versatile strategy for generating radicals. However, the electronic constraints of the donor and acceptor components can limit the range of radicals that can be generated. By using sulfonium salts in electron donor-acceptor complexation, radicals can now be generated from native functionality. This approach relaxes the electronic constraints and expands the range of radicals that can be generated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Courtney A. DelPo, Saeed-Uz-Zaman Khan, Kyu Hyung Park, Bryan Kudisch, Barry P. Rand, Gregory D. Scholes
Summary: Enhanced delocalization is beneficial for absorbing molecules in organic solar cells, and polaritons offer exceptional delocalization that can improve the efficiency of bilayer organic photovoltaics by aiding in exciton delivery to the donor-acceptor interface. The decay of polaritons in bilayer cavities shows an additional pathway through charge transfer, indicating that the charge transfer from the polariton is fast enough to outcompete decay to the ground state.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Ying-Ying Peng, Bi-Fei Li, Peng Li, Yi Hou, Bing Guo, Qunhui Yuan, Wei Gan
Summary: Two water-soluble dyes with conjugated donor-acceptor structures were designed and their second-order nonlinear optical properties and fluorescence efficiencies were studied. The modified molecules emitted much less two-photon fluorescence than dye D289 due to nonradiative transitions caused by molecular motions in solution. TPAPM exhibited higher NLO performance than D289 and TPAP because of the strong electron pull-push effect operating along the D-pi-A backbone, making it a promising SHG probe molecule for multimodal imaging in biological applications.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Applied
Xiaoyu Zhao, Ivan Kurganskii, Ayhan Elmali, Jianzhang Zhao, Ahmet Karatay, Gloria Mazzone, Matvey Fedin
Summary: A series of compact coumarin-anthracene donor-acceptor dyads were synthesized to investigate the relationship between molecular configuration, electronic coupling, and intersystem crossing (ISC) efficiency. The results showed that the orthogonal geometry of the dyads was beneficial to the spin-orbit charge transfer ISC (SOCT-ISC) mechanism. Singlet oxygen quantum yields were solvent polarity-dependent, and the orthogonal dyads exhibited higher yields compared to the coplanar dyad. Transient absorption spectra revealed different localized and delocalized triplet states in the dyads, with varied lifetimes. Time-resolved electron paramagnetic resonance (TREPR) spectra confirmed the involvement of the SOCT-ISC mechanism in orthogonal dyads, while both SOCT-ISC and spin-orbit ISC (SO-ISC) mechanisms contributed to the triplet state formation in the coplanar dyad. The electron spin polarization (ESP) pattern of the triplet states depended on not only the molecular geometry but also the electron donor and acceptor structure.
Article
Chemistry, Multidisciplinary
Chen Lu, Eunkyung Cho, Zhiyuan Cui, Yuhang Gao, Wenjuan Cao, Jean-Luc Bredas, Veaceslav Coropceanu, Feng Li
Summary: In contrast to closed-shell luminescent molecules, organic luminescent radicals have both spin doublet electronic states, resulting in spin-allowed radiative transitions. The efficiency and stability of donor-acceptor (D-A center dot) type luminescent radicals, which have a donor group covalently attached to an electron-withdrawing radical core, remain challenging to define. Experimental and theoretical results suggest that the luminescence efficiency and stability of the radicals are determined by the degree of conjugation and the number of imine nitrogen atoms in the substituents, with higher conjugation and lower number of imine nitrogen atoms leading to higher efficiency and stability.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kevin Bold, Matthias Stolte, Kazutaka Shoyama, Marco Holzapfel, Alexander Schmiedel, Christoph Lambert, Frank Wuerthner
Summary: Two macrocyclic architectures comprising oligothiophene strands that connect the imide positions of a perylene biscimide (PBI) dye have been synthesized via a platinum-mediated cross-coupling strategy. The crystal structure of the double bridged PBI reveals all syn-arranged thiophene units enclosed a planar PBI chromophore via a 12-membered macrocycle. The target structures exhibit ultrafast Forster Resonance Energy Transfer and photoinduced electron transfer, resulting in extremely low fluorescence quantum yields even in the lowest polarity cyclohexane solvent.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Joshua Selby, Marco Holzapfel, Krzysztof Radacki, Asim Kumar Swain, Holger Braunschweig, Christoph Lambert
Summary: This study investigates the influence of chirality on the structure and properties of cisoid indolenine squaraine polymers with different side chains. The absorption spectroscopy and circular dichroism results show that the behavior of the polymers is strongly dependent on the solvent and the type of side chains. The temperature-dependent absorption spectroscopy reveals the thermodynamic parameters of helix folding and suggests that increasing the steric demand of the side chains leads to an increase in entropy and enthalpy. Fluorescence spectroscopy confirms the structural characteristics of the polymers.
Article
Chemistry, Multidisciplinary
Rebecca Renner, Matthias Stolte, Julia Heitmueller, Tobias Brixner, Christoph Lambert, Frank Wuerthner
Summary: The study focused on the functional properties of different PBI anions and dianions with varying bay-substituents, revealing significant changes in their absorption spectra, indicating their potential for optoelectronic device applications.
MATERIALS HORIZONS
(2022)
Article
Chemistry, Multidisciplinary
Goutam Kumar Kole, Marta Koscak, Anissa Amar, Dragomira Majhen, Ksenija Bozinovic, Zlatko Brkljaca, Matthias Ferger, Evripidis Michail, Sabine Lorenzen, Alexandra Friedrich, Ivo Krummenacher, Michael Moos, Holger Braunschweig, Abdou Boucekkine, Christoph Lambert, Jean-Francois Halet, Ivo Piantanida, Klaus Mueller-Buschbaum, Todd B. Marder
Summary: A series of bis-(4'-pyridylethynyl)arenes were synthesized and investigated for their photophysical and electrochemical properties, as well as their interactions with DNA/RNA. These compounds showed potential as therapeutic and diagnostic agents due to their interactions with DNA/RNA.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Kevin Bold, Matthias Stolte, Kazutaka Shoyama, Ana-Maria Krause, Alexander Schmiedel, Marco Holzapfel, Christoph Lambert, Frank Wuerthner
Summary: In this study, a series of donor-acceptor macrocyclic dyads were synthesized and characterized. It was found that controlling the conformation of the macrocycle allowed for fine tuning of the absorption spectra, and the size of the oligothiophene bridge played a role in the fast charge transfer process in the excited state dynamics.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Thomas Wiesner, Zhu Wu, Jie Han, Lei Ji, Alexandra Friedrich, Ivo Krummenacher, Michael Moos, Christoph Lambert, Holger Braunschweig, Benjamin Rudin, Hilmar Reiss, Olena Tverskoy, Frank Rominger, Andreas Dreuw, Todd B. Marder, Jan Freudenberg, Uwe H. F. Bunz
Summary: Tetraiodotetraazapentacene I(4)TAP, a new derivative in the series of halogenated silylated tetraazapentacenes, has been successfully synthesized and characterized by crystallography. Its air-stable monoanion and relatively air-stable dianion were obtained through reduction reactions and also confirmed by crystallography. Additionally, the structural and spectroscopic properties of I(4)TAP were compared to non-halogenated TAP and Br(4)TAP. It was found that I(4)TAP exhibits high electron mobility in thin-film transistors.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Ksenija Bozinovic, Davor Nestic, Evripidis Michail, Matthias Ferger, Marta Koscak, Christoph Lambert, Dragomira Majhen, Todd B. Marder, Ivo Piantanida
Summary: We reported a new type of compound that shows remarkable sensing ability in DNA/RNA and also exhibits biological activity in photodynamic therapy, making them potential therapeutic probes. These compounds can effectively enter living cells with negligible inhibition on cell proliferation. Regarding viruses, some of these compounds have high affinity to adenovirus type 5 and can weaken its ability to infect human cells. Upon visible light irradiation, these compounds generate reactive oxygen species, resulting in a significant increase in cytotoxicity and antiviral activity.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
(2022)
Article
Chemistry, Physical
Julian Luettig, Peter A. Rose, Pavel Maly, Arthur Turkin, Michael Buehler, Christoph Lambert, Jacob J. Krich, Tobias Brixner
Summary: Time-resolved spectroscopy is widely used to study various phenomena in chemistry, biology, and physics. This study focuses on pump-probe experiments and coherent two-dimensional (2D) spectroscopy, which have been successful in visualizing energy transfer and electronic couplings. The researchers demonstrate that the appearance of a two-quantum (2Q) signal indicates the contamination of a one-quantum (1Q) signal by non-negligible fifth-order interactions. By performing partial integrations, the study shows that clean rQ signals can be obtained in 2D spectra, free from higher-order artifacts.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Organic
Emely Freytag, Lasse Kreimendahl, Marco Holzapfel, Jens Petersen, Heiko Lackinger, Matthias Stolte, Frank Wuerthner, Roland Mitric, Christoph Lambert
Summary: Five chiral squaraine dimers were synthesized by fusing chiral indolenine semisquaraines with three different benzobisthiazole bridges. The resulting dimers exhibited strong splitting of the lowest energy absorption bands due to exciton coupling. The electric circular dichroism spectra of the dimers showed intense Cotton effects whose sign depended on the used squaraine chromophores. TD-DFT calculations revealed that the electric-magnetic coupling was the dominant contribution to the rotational strength.
JOURNAL OF ORGANIC CHEMISTRY
(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
Lea Ress, Pavel Maly, Jann B. Landgraf, Dominik Lindorfer, Michael Hofer, Joshua Selby, Christoph Lambert, Thomas Renger, Tobias Brixner
Summary: This article presents the experimental and theoretical foundations for femtosecond time-resolved circular dichroism (TRCD) spectroscopy of excitonic systems. A new experimental setup, with a polarization grating as the key element, is introduced to generate circularly polarized pulses for TRCD experiments. By applying a specific chopping scheme, left and right circular polarizations can be switched, and transient absorption (TA) and TRCD spectra can be detected simultaneously. Experiments on a squaraine polymer are performed to investigate excitonic dynamics, and a general theory for TRCD experiments of excitonically coupled systems is developed and applied to describe the experimental data.
Article
Chemistry, Multidisciplinary
Fridolin Saal, Asim Swain, Alexander Schmiedel, Marco Holzapfel, Christoph Lambert, Prince Ravat
Summary: We describe a helically chiral push-pull molecule named 9,10-dimethoxy-[7]helicene diimide, which exhibits fluorescence and circularly polarised luminescence over nearly the entire visible spectrum dependent on solvent polarity, along with high dissymmetry factors.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Emely Freytag, Marco Holzapfel, Asim Swain, Gerhard Bringmann, Matthias Stolte, Frank Wuerthner, Christoph Lambert
Summary: Yamamoto homocoupling of two chiral oxindoles led to the formation of an axially chiral oxindole dimer. This dimer served as the starting material for the syntheses of axially chiral squaraine and merocyanine chromophore dimers. The chiroptical properties of these dimers, including high ECD signals and circularly polarised emission, were analyzed using computational calculations, which showed that exciton coupling is the dominant contributor to the rotational strength.
Article
Chemistry, Physical
Paul Mentzel, Marco Holzapfel, Alexander Schmiedel, Ivo Krummenacher, Holger Braunschweig, Artur Wodynski, Martin Kaupp, Frank Wuerthner, Christoph Lambert
Summary: While spin-orbit coupling is not crucial for the photophysics of unsubstituted perylene diimides (PDI), it plays a dramatic role when two phenylselenyl or phenyltelluryl substituents are attached to the PDI bay positions. The introduction of these substituents leads to a decrease in fluorescence quantum yield and an increase in intersystem crossing (ISC) rate. Time-dependent density functional calculations suggest that increased spin-orbit coupling is due to the internal heavy-atom effect, resulting in fast ISC. Moreover, the selenium PDI derivative shows significant sensitization of singlet oxygen via the PDI triplet state.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Lei Ji, Stefan Riese, Alexander Schmiedel, Marco Holzapfel, Maximillian Fest, Joern Nitsch, Basile F. E. Curchod, Alexandra Friedrich, Lin Wu, Hamad H. Al Mamari, Sebastian Hammer, Jens Pflaum, Mark A. Fox, David J. Tozer, Maik Finze, Christoph Lambert, Todd B. Marder
Summary: Reversible conversion between excited states is crucial in various photophysical phenomena. By conducting experiments and calculations, we discovered that the energy gaps and barriers among the locally-excited and charge-transfer states in 1-(pyren-2'-yl)-o-carborane are negligible, making all three states accessible at room temperature. Furthermore, the internal-conversion and reverse internal-conversion processes occur much faster than radiative decay, resulting in the same lifetimes and thermodynamic equilibrium of the two states.