Article
Chemistry, Multidisciplinary
Martin L. Kirk, David A. Shultz, Patrick Hewitt, Ju Chen, Art van der Est
Summary: Photoinduced electron spin polarization (ESP) in the ground state of luminescent materials is investigated, and the phenomenon is found to be influenced by the connecting structure and have a relatively long duration.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Douglas J. Grzetic, Kris T. Delaney, Glenn H. Fredrickson
Summary: Microphase separation in a binary blend of oppositely charged polymers can be stabilized electrostatically, providing a route to control microstructure. The phase behavior is affected by differences in charge density and dielectric constant of the polymers, and specific ordered phases can be stabilized when the minority component has a higher dielectric constant. This system suggests a possible route to large-unit-cell complex-sphere phases.
Article
Chemistry, Multidisciplinary
Daisuke Yoshioka, Yusuke Yoneda, I-Ya Chang, Hikaru Kuramochi, Kim Hyeon-Deuk, Yoichi Kobayashi
Summary: Organic-inorganic nanohybrids using semiconductor nanocrystals coordinated with aromatic organic molecules have been extensively studied in optoelectronic materials. This study demonstrates the reversible displacement of coordination bonds between ligand molecules and zinc sulfide nanocrystals by light irradiation. Time-resolved spectroscopy and density functional theory calculations reveal that the displacement is driven by ultrafast hole transfer and the surviving radical anion of the ligand. These photoinduced ligand displacements have implications for the development of advanced photofunctional materials.
Article
Multidisciplinary Sciences
K. L. Hudson, A. Srinivasan, O. Goulko, J. Adam, Q. Wang, L. A. Yeoh, O. Klochan, I Farrer, D. A. Ritchie, A. Ludwig, A. D. Wieck, J. von Delft, A. R. Hamilton
Summary: This study investigates a series of low disorder p-type GaAs quantum point contacts, exploring a new signature for detecting spin gaps that is insensitive to disorder. By examining the linear and non-linear response to the orientation of the applied magnetic field, the authors successfully extract a spin-orbit gap of approximately 500 microelectron volts.
NATURE COMMUNICATIONS
(2021)
Article
Spectroscopy
Xinyue Wang, Hongxiang Wang, Meixia Zhang, Tonu Pullerits, Peng Song
Summary: Based on Marcus theory, the photoinduced electron transfer properties of D-A type non-fullerene acceptor organic solar cells (OSCs) under the dependence of external electric field (F-ext) were investigated. The research found that the charge transfer mode changes with the intensity of external electric field and the important parameters (delta G, lambda, and V-DA) play a crucial role in the charge transfer rate.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Chemistry, Organic
Sudhakar Ganta, Jan-Hendrik Borter, Christoph Drechsler, Julian J. Holstein, Dirk Schwarzer, Guido H. Clever
Summary: A [Pd2L4] coordination cage, consisting of electron-rich phenothiazine-based ligands and encapsulating an electron-deficient anthraquinone-based disulfonate guest, has been reported. Transient absorption spectroscopy reveals photoinduced electron transfer from the host's chromophores to the guest, as indicated by characteristic spectral features. The host-guest complex was characterized using various techniques, and spectroelectrochemical experiments and DFT calculations support the proposed light-induced charge separation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Materials Science, Multidisciplinary
Lina G. Johnsen, Jacob Linder
Summary: The spin transport inside an odd-frequency spin-triplet superconductor is different from that of a conventional superconductor, with unique symmetry properties and the potential for larger spin injection. When odd-frequency pairing inherits its temperature dependence from a conventional superconductor, the density of states can transition from gapless to gapped, leading to a peak in spin accumulation larger than in the normal state. In odd-frequency superconductors, the spin-orbit scattering time decreases below the superconducting transition temperature, particularly for energies close to the gap edge.
Article
Materials Science, Multidisciplinary
V Tiwari, M. Morita, T. Inoue, S. Ando, S. Kuroda, H. Boukari, L. Besombes
Summary: This article investigates the dynamics of a spin system composed of a positively charged II-VI semiconductor quantum dot doped with a single Cr+ ion. The resonant photoluminescence (PL) of the positively charged exciton coupled with the Cr+ spin is used to analyze the main spin relaxation channels. Optical pumping of the spin of the resident hole-Cr+ complex reduces the intensity of resonant PL, acting as a nanomagnet. Nonresonant optical excitation partially erases the spin memory, leading to an increase in resonant PL signal. The observed optical transitions with a change in the Cr+ spin in the resonant-PL excitation spectra allow the determination of the magnetic anisotropy of the magnetic atom. Optical excitation affects the effective temperature of the hole-Cr+ spin system through the local generation of phonons, as shown by optical pumping, autocorrelation measurements, and power dependence of PL intensity distribution.
Article
Chemistry, Physical
M. Reale, S. Chandra, G. Buscarino, A. Emanuele, M. Cannas, O. Ikkala, A. Sciortino, F. Messina
Summary: Nanoscience has recently gained increasing attention for the easy assembly of established nanomaterials into hybrid nanostructures, and here researchers studied the photophysicochemical response of binary nanohybrids formed by coupling luminescent carbon dots to silver nanoparticles. The successful coupling was confirmed by optical measurements and direct imaging, and the nanohybrids showed strong interactions and sub-picosecond electron transfer. These self-assembled carbon-silver nanohybrids demonstrated significant photocatalytic performance, indicating their potential as eco-friendly materials for light-driven catalytic applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Jasleen K. Bindra, Jens Niklas, Yeonjun Jeong, Ahren W. Jasper, Moritz Kretzschmar, Jan Kern, Lisa M. Utschig, Oleg G. Poluektov
Summary: This publication presents the first comprehensive experimental study of electron spin coherences in photosynthetic reaction center proteins, specifically focusing on photosystem I (PSI). The study reveals the challenges posed by electron spin decoherence in practical applications of electron spin qubits and provides a systematic characterization of decoherence in SCRPs of PSI.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Materials Science, Multidisciplinary
Birender Singh, Deepu Kumar, Vivek Kumar, Michael Vogl, Sabine Wurmehl, Saicharan Aswartham, Bernd Buchner, Pradeep Kumar
Summary: Our study involves comprehensive inelastic light scattering measurements on the Ir-based double perovskite Gd2ZnIrO6 over a wide temperature range, revealing signs of spin fractionalization within the paramagnetic phase as temperature decreases, indicating the presence of a proximate quantum spin liquid phase.
Article
Chemistry, Physical
Rea Divina Mero, Chun-Hao Lai, Chao-Hung Du, Hsiang-Lin Liu
Summary: CuB2O4 has unique chemical and physical properties, such as band gap redshift and phonon softening phenomena, indicating the presence of complex spin-charge-lattice interactions in CuB2O4.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Alberto Privitera, Emilio Macaluso, Alessandro Chiesa, Alessio Gabbani, Davide Faccio, Demetra Giuri, Matteo Briganti, Niccolo Giaconi, Fabio Santanni, Nabila Jarmouni, Lorenzo Poggini, Matteo Mannini, Mario Chiesa, Claudia Tomasini, Francesco Pineider, Enrico Salvadori, Stefano Carretta, Roberta Sessoli
Summary: We provide direct proof that time-resolved electron paramagnetic resonance (EPR) can be used to detect long-lived spin polarization generated by photoinduced charge transfer through a chiral bridge. This work lays the basis for the optical generation and direct manipulation of spin polarization induced by chirality.
Article
Materials Science, Multidisciplinary
Junpei Sonehara, Michael Kammermeier, Dai Sato, Daisuke Iizasa, Ulrich Zulicke, Shutaro Karube, Junsaku Nitta, Makoto Kohda
Summary: The anisotropic spin dynamics in wires based on a [001]-oriented semiconductor quantum well were investigated, revealing that the spin relaxation time is longest for the in-plane magnetic field perpendicular to the spin-orbit field, while the shortest for the parallel configuration. The precession frequency exhibits opposite symmetry, allowing for the evaluation of spin-orbit coefficients and a greater understanding of quantum and topological information in semiconductor one-dimensional wires.
Article
Chemistry, Multidisciplinary
Yuanfu Ren, Ting Zhu, Yadong Liu, Quanbing Liu, Qingyu Yan
Summary: Electrochemical energy storage using hierarchical light-sensitive material has shown enhanced charge storage capability under light irradiation, offering new possibilities for utilizing sustainable solar energy for improved energy storage devices.
Article
Chemistry, Multidisciplinary
Aaron G. Nash, Colton J. Breyer, Brett D. Vincenzini, Gregory I. Elliott, Jens Niklas, Oleg G. Poluektov, Arnold L. Rheingold, Diane K. Smith, Djamaladdin G. Musaev, Douglas B. Grotjahn
Summary: This study reports a catalyst that maintains high electrocatalytic turnover frequency at very low pH values, with high current densities and excellent durability. Preliminary computational studies suggest that the sulfonate group in the active site acts as a proton relay even in strong acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Applied
Henry Wladkowski, Julian Duarte, Shashank R. Nandyala, Joshua S. Walker, Subash Kattel, Jeffrey L. Blackburn, Jeffrey A. Fagan, Jon M. Pikal, William D. Rice
Summary: This study presents a rapid, easy, and economical technique for producing PVAc-based NP-polymer films with high uniformity and excellent optical properties. The films exhibit robustness at low temperatures and are suitable for pulsed laser measurements. Incorporating one-dimensional SWCNTs and zero-dimensional Au NPs, these films maintain individualization of the nanotubes and low aggregation.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Hannah Sayre, Hunter H. Ripberger, Emmanuel Odella, Anna Zieleniewska, Daniel A. Heredia, Garry Rumbles, Gregory D. Scholes, Thomas A. Moore, Ana L. Moore, Robert R. Knowles
Summary: By incorporating benzimidazole-phenol (BIP) into a photocatalyst, the charge recombination rate can be significantly slowed down, leading to an over 2-fold increase in reaction quantum efficiency for the photocatalytic phthalimide ester reduction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Physics, Atomic, Molecular & Chemical
Jens Niklas, Udita Brahmachari, Lisa M. Utschig, Oleg G. Poluektov
Summary: Nature has optimized photosynthetic machinery over billions of years, utilizing protein-cofactor complexes for electron transfer, but conventional EPR suffers from severe spectral overlap. High-frequency EPR studies of Photosystem I help in understanding electronic structures of cofactors and interactions between nitrogen atoms.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Chemistry, Multidisciplinary
Joshua M. Carr, Taylor G. Allen, Bryon W. Larson, Iryna G. Davydenko, Raghunath R. Dasari, Stephen Barlow, Seth R. Marder, Obadiah G. Reid, Garry Rumbles
Summary: This study presents a simple model to explain how Frenkel excitons efficiently split to form free-charges in low-dielectric constant organic semiconductors. Through a series of experiments, it is demonstrated that the model can explain many seemingly contradictory phenomena reported in the literature.
MATERIALS HORIZONS
(2022)
Article
Chemistry, Multidisciplinary
J. D. Earley, A. Zieleniewska, H. H. Ripberger, N. Y. Shin, M. S. Lazorski, Z. J. Mast, H. J. Sayre, J. K. McCusker, G. D. Scholes, R. R. Knowles, O. G. Reid, G. Rumbles
Summary: Cyclometalated and polypyridyl complexes of d(6) metals have great potential as photoredox catalysts, and besides the known criteria for modifying activity, such as tuning redox potentials, absorption energy, excited-state lifetime, and quantum yield, ion pair reorganization may also be an important factor in controlling reactivity.
Article
Plant Sciences
Jens Niklas, Alessandro Agostini, Donatella Carbonera, Marilena Di Valentin, Wolfgang Lubitz
Summary: The photoexcited triplet state of the primary donors in the two photosystems of oxygenic photosynthesis has been investigated using the electron-nuclear double resonance (ENDOR) technique. The results confirm that the primary donor triplet is located on a specific chlorophyll molecule in both photosystems at cryogenic temperature. This research provides important insights into the mechanism of photosynthesis.
PHOTOSYNTHESIS RESEARCH
(2022)
Article
Chemistry, Physical
Alon Chapovetsky, Robert M. Kennedy, Ryan Witzke, Evan C. Wegener, Fulya Dogan, Prajay Patel, Magali Ferrandon, Jens Niklas, Oleg G. Poluektov, Ning Rui, Sanjaya D. Senanayake, Jose A. Rodriguez, Nestor J. Zaluzec, Lei Yu, Jianguo Wen, Christopher Johnson, Cynthia J. Jenks, A. Jeremy Kropf, Cong Liu, Massimiliano Delferro, David M. Kaphan
Summary: This article describes the application of Li-ion battery cathode and anode materials as redox non-innocent catalyst supports for the electronic tuning of a catalyst's active site. The activity of the catalyst for olefin hydrogenation was found to increase as a function of support reductive lithiation. Simulation results reveal the significant impact of surface redox states on the viability of the homolytic oxidative addition mechanism.
Article
Chemistry, Physical
Xunshan Liu, Jiaze Xie, Jens Niklas, Emigdio E. Turner, Dafei Yuan, John S. Anderson, Jeffrey J. Rack, Oleg G. Poluektov, Luping Yu
Summary: A donor-acceptor conjugated copolymer containing thienothiophene units and Co(II) complexes has been synthesized and characterized. The study showed antiferromagnetic exchange interaction between neighboring spin centers along with the polymer backbone through intrachain interactions. The magneto-optical activity of the polymer was also characterized using magnetic circular dichroism spectroscopy.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Max M. O'Connor, Taylor J. Aubry, Obadiah G. Reid, Garry Rumbles
Summary: Time-resolved microwave conductivity is used to compare the photocatalytic activity of aqueous-soluble organic nanoparticle and bulk thin films composed of the same mixture of semiconducting polymer and non-fullerene acceptor molecule. The results show that nanoparticle photocatalytic activity corresponds directly to charge generation and has 3x more long-lived accumulated charges relative to bulk samples. The concentration of electrons and holes in operando limits the catalytic activity by the nanoparticles, providing a clear design goal for the next generation of efficient photocatalytic nanoparticles.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Xin Zheng, Matthew C. Drummer, Haiying He, Thomas M. Rayder, Jens Niklas, Nicholas P. Weingartz, Igor L. Bolotin, Varun Singh, Boris V. Kramar, Lin X. Chen, Joseph T. Hupp, Oleg G. Poluektov, Omar K. Farha, Peter Zapol, Ksenija D. Glusac
Summary: This study investigates the mechanism of photochemical CO2 reduction to formate by a Zr-based metal-organic framework (MOF) called PCN-136, which incorporates light-harvesting nanographene ligands. Steady-state and time-resolved spectroscopy and density functional theory (DFT) calculations were used. The catalysis was found to proceed via a photoreactive capture mechanism, where Zr-based nodes capture CO2 as Zr-bicarbonates, while the nanographene ligands absorb light and store one-electron equivalents for the catalysis. The findings highlight the advantages of MOF-based architectures in molecular photocatalyst engineering and provide insights on achieving high formate selectivity.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Autumn Y. Lee, Troy A. Colleran, Amisha Jain, Jens Niklas, Brandon K. Rugg, Tomoyasu Mani, Oleg G. Poluektov, Jacob H. Olshansky
Summary: The inherent spin polarization in photogenerated spin-correlated radical pairs makes them promising for quantum computing and quantum sensing. In this work, dye molecule-inorganic quantum dot conjugates are prepared and shown to produce photogenerated spin-polarized states. By performing optical spectroscopy and electron paramagnetic resonance experiments, it is demonstrated that the spin states can be accessed and manipulated with microwave pulses. This work opens up possibilities for using highly tailorable inorganic nanoparticles as a new class of qubit materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Garrett L. Grocke, Ban Xuan Dong, Aaron D. Taggart, Alex B. F. Martinson, Jens Niklas, Oleg G. Poluektov, Joseph W. Strzalka, Shrayesh N. Patel
Summary: This study focuses on the humidity-dependent structure-transport properties of polymeric MIECs with varied side-chain lengths. The results show that hydration improves electronic transport and humidity has a positive effect on ionic conductivity but a non-monotonic effect on electronic conductivity.
Article
Chemistry, Multidisciplinary
Lisa M. Utschig, Udita Brahmachari, Karen L. Mulfort, Jens Niklas, Oleg G. Poluektov
Summary: Flavin chemistry plays a ubiquitous role in biological systems, especially in photosynthesis where it facilitates electron transfer and charge accumulation. Understanding the mechanisms of photosynthetic charge accumulation is important for the development of photon-to-fuel schemes. This study reveals the crucial role of flavoproteins in the light-driven electron transfer chain and provides valuable insights for further research in this area.
Article
Materials Science, Multidisciplinary
Anna Zieleniewska, Fabian Lodermeyer, Maurizio Prato, Garry Rumbles, Dirk M. Guldi, Jeffrey L. Blackburn
Summary: Single-walled carbon nanohorns are a carbon allotrope with promising applications, and through thermopower measurements, it has been determined that SWCNH behaves as a p-type semiconductor.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
