Article
Chemistry, Multidisciplinary
Arianna Actis, Michele Melchionna, Giacomo Filippini, Paolo Fornasiero, Maurizio Prato, Enrico Salvadori, Mario Chiesa
Summary: This study assesses the influence of morphology and light-excitation on the number and chemical nature of radical defects in carbon nitride (CN) and derives the spatial distribution of native radicals in CN using magnetic dipole-dipole coupling.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Physical
Burkhard Endeward, Matthias Bretschneider, Paul Trenkler, Thomas F. Prisner
Summary: In this paper, the application of shaped pulses in EPR spectroscopy is described. Fast arbitrary waveform generators are used to generate pulses for broadband excitation of paramagnetic species. The implementation and optimization of these broadband pulses in existing EPR spectrometers are discussed in detail. Shaped pulses are also reviewed for their applications in broadband inversion of longitudinal magnetization and creation/manipulation of transverse magnetization in dipolar and hyperfine EPR spectroscopy, demonstrating their potential to improve the performance of pulsed EPR experiments.
PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
(2023)
Article
Chemistry, Multidisciplinary
Fabian Hecker, Lisa Fries, Markus Hiller, Mario Chiesa, Marina Bennati
Summary: The hydration structure of nitroxide radicals in aqueous solutions is studied using advanced O-17 hyperfine (hf) spectroscopy, quantum chemical calculations, and MD simulations. Two different nitroxide radicals with piperidine and pyrrolidine-based groups are compared, revealing distinct differences in the preferred direction of H-bond formation. The O-17 hf spectra provide the best representation of these scenarios, showing that in-plane coordination leads to little spin density transfer and small hf couplings, while perpendicular coordination generates larger hf couplings. The quantitative analysis based on MD simulations and DFT predicted hf parameters confirms a distribution of solvating water molecules, where directionality is influenced by steric effects.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yunfan Qiu, Asif Equbal, Chenjian Lin, Yuheng Huang, Paige J. Brown, Ryan M. Young, Matthew D. Krzyaniak, Michael R. Wasielewski
Summary: Photoexcited organic chromophores combined with stable radicals can be used as candidates for quantum information applications. In this study, the synthesis and characterization of 1,6,7,12-Tetra-(4-tert-butylphenoxy)-perylene-3,4 : 9,10-bis(dicarboximide) (tpPDI) linked to a partially deuterated alpha,gamma-bisdiphenylene-beta-phenylallyl radical (BDPA-d(16)) were performed using time-resolved optical and electron paramagnetic resonance (EPR) spectroscopies. The results showed efficient generation of a quartet state (Q) followed by a spin-polarized doublet ground state (D-0) upon photoexcitation of tpPDI-BDPA-d(16).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Biochemistry & Molecular Biology
Tarek Al Said, Stefan Weber, Erik Schleicher
Summary: This study explores the potential of out-of-phase-electron-spin echo envelope modulation (OOP-ESEEM) spectroscopy in collecting accurate distance information in photo-sensitive (bio) molecules. The OOP-ESEEM time traces were simulated and analyzed to obtain excellent agreement between calculated and numerically fitted values over a wide range of distances.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Maite Noessler, Nicolas I. Neuman, Lisa Boeser, Rene Jaeger, Arijit Singha Hazari, David Hunger, Yixian Pan, Clemens Luecke, Tobias Bens, Joris van Slageren, Biprajit Sarkar
Summary: Terpyridine ligands are widely studied in coordination chemistry and materials science due to their stable complex formation ability with various transition metal ions. In this study, three terpyridine ligands with different perfluorocarbon (PFC) tails on the backbone, along with their Fe-II and Co-II complexes, were reported. The Co-II complexes exhibited spin crossover near room temperature, which was influenced by the length of the PFC tail. Electrochemical properties of the metal complexes were investigated using cyclic voltammetry, revealing oxidation and reduction processes. EPR measurements were used to study fluorine-specific interactions, showing exchange-narrowed spectra without hyperfine splittings from the Co-59 nucleus, indicating complex aggregation mediated by PFC tail interactions in solution. Interestingly, the addition of perfluoro-octanol disrupted the F...F interactions of the tails. To our knowledge, this is the first EPR spectroscopy study on fluorine-specific interactions in metal complexes, demonstrated by exchange narrowing.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Physics, Multidisciplinary
Timur V. Tscherbul, Jun Ye, Ana Maria Rey
Summary: We propose a general protocol for generating robust entangled states of nuclear and/or electron spins of ultracold polar molecules using electric dipolar interactions. By encoding a spin-1/2 degree of freedom in a combined set of spin and rotational molecular levels, we theoretically demonstrate effective spin-spin interactions enabled by efficient magnetic control over electric dipolar interactions. These interactions can be used to create long-lived cluster and squeezed spin states.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Joshua L. Wort, Swati Arya, Katrin Ackermann, Alan J. Stewart, Bela E. Bode
Summary: Pulse-dipolar EPR is an attractive method for structural characterization in solution, especially when paired with genetically encoded self-assembling spin labels and Cu-II-chelates. The combination of room-temperature isothermal titration calorimetry and cryogenic relaxation-induced dipolar modulation enhancement showed that the double-histidine motif spin labeling with Cu-II-nitrilotriacetic acid is robust against competition from Zn-II-NTA and maintains high nM binding affinity even under acidic and basic conditions. The strategy is well-suited for diverse biological applications, with the requirement of other metal ion cofactors or slightly acidic pH not necessarily being prohibitive.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Mohammad Haidar, Vladimir I. Korobov, Laurent Hilico, Jean -Philippe Karr
Summary: This study focuses on higher-order corrections to the spin-orbit and spin-spin tensor interactions in hydrogen molecular ions. The authors derive the m alpha 7ln(alpha)-order radiative correction using the NRQED framework. Complete numerical calculations, including the m alpha 6-order relativistic correction, are presented for the case of H-2(+). The theoretical uncertainty is significantly reduced compared to the Breit-Pauli level, to a few ppm. The results are also compared with available rf spectroscopy data.
Article
Chemistry, Multidisciplinary
Wei-Ling Jiang, Zhiyong Peng, Bin Huang, Xiao-Li Zhao, Di Sun, Xueliang Shi, Hai-Bo Yang
Summary: This study systematically investigated the spin-spin interactions of exo- and endo-TEMPO radical-functionalized metallacycles and metallacages constructed via coordination-driven self-assembly. The results revealed distinct spin-spin interactions in solution and solid states, with a large zero-field splitting observed in certain crystalline forms. Moreover, reversible on-off switching of the zero-field splitting was successfully achieved via crystal-to-amorphous transformation induced by mechanical grinding and solvent vapor stimuli.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Optics
Pavel Fadeev, Filip Ficek, Mikhail G. Kozlov, Dmitry Budker, Victor V. Flambaum
Summary: Unknown elementary particles can be searched for using atomic spectroscopy, with potentials resulting from pseudoscalar and pseudovector particles. Interaction constants of these potentials can be extracted from experimental spectra.
Article
Chemistry, Multidisciplinary
Fangbai Xie, Haochuan Mao, Chenjian Lin, Yuanning Feng, J. Fraser Stoddart, Ryan M. Young, Michael R. Wasielewski
Summary: This study demonstrates that a photogenerated spin-correlated radical ion pair can be used to sense an electric field change through molecular recognition. The experiment shows that the distance between the two charges decreases when a certain molecule encapsulates one of the charges, indicating that the system can function as a quantum sensor to detect electric field changes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Ryan D. D. Dill, Kori E. E. Smyser, Brandon K. K. Rugg, Niels H. H. Damrauer, Joel D. D. Eaves
Summary: Singlet fission is important for next-generation solar cells. The authors design a molecular system with specific spin sub-levels that can produce highly entangled states. They demonstrate that the coherence between magnetic sub-levels of that state can be preserved at higher temperatures than conventional superconducting quantum hardware.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Daniel Ossadnik, Sergei Kuzin, Mian Qi, Maxim Yulikov, Adelheid Godt
Summary: The narrow central line and weak zero-field splitting (ZFS) of [GdIII(NO3Pic)] make it an attractive starting point for the development of spin labels. A substituent of alkyl with a remote functional group at the picolinate moiety can retain the narrow line and weak ZFS even with broken axial symmetry. By chemoselective labeling reaction, a spin label targeting cysteines in peptides (NDSE-{GdIII(NO3Pic)}) has been successfully designed for distance determination in peptides.
INORGANIC CHEMISTRY
(2023)
Article
Polymer Science
Iulia Matei, Ana-Maria Ariciu, Elena Irina Popescu, Sorin Mocanu, Alexandru Vincentiu Florian Neculae, Florenta Savonea, Gabriela Ionita
Summary: In this study, the accessibility of spin probes with different molecular weights in various hydrogels was investigated using EPR spectroscopy. The results showed that the size of the diffusing species determines the gel's ability to uptake them, and EPR spectra also revealed specific interactions of the spin probes inside the gels.
Article
Chemistry, Multidisciplinary
Jerome Robert, Nathalie Parizel, Philippe Turek, Athanassios K. Boudalis
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2019)
Article
Chemistry, Inorganic & Nuclear
Jessica M. Lopez Pla, Athanassios K. Boudalis, Joshua Telser, Raphael G. Raptis
INORGANICA CHIMICA ACTA
(2020)
Article
Chemistry, Multidisciplinary
Logesh Mathivathanan, Guillaume Rogez, Nadia Ben Amor, Vincent Robert, Raphael G. Raptis, Athanassios K. Boudalis
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Review
Chemistry, Multidisciplinary
Athanassios K. Boudalis
Summary: This review presents the history of study on spin triangles, discusses the parallel development of new experimental investigations and new theoretical ideas, as well as their chemical diversity and relevance to spintronic devices and new physics.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Seda Kartal, Guillaume Rogez, Jerome Robert, Benoit Heinrich, Athanassios K. Boudalis
Summary: [Gd-5(L)(16)(H2O)(8)](Tf2N)(15) obtained from the reaction was found to be a frozen organic glass liquid with weak magnetic intramolecular interactions, exhibiting a magnetocaloric effect.
Article
Chemistry, Multidisciplinary
Jordan L. Appleton, Nolwenn Le Breton, Mary-Ambre Carvalho, Jean Weiss, Athanassios K. Boudalis, Christophe Gourlaouen, Sylvie Choua, Romain Ruppert
Summary: The synthesis of new vanadyl porphyrins with peripheral coordination sites is reported. Porphyrin dimers were isolated and characterized by X-ray crystallography using palladium(II) or platinum(II) as connecting ions. These paramagnetic species were studied by electronic spectroscopy and continuous wave electron paramagnetic resonance (CW EPR). Large bathochromic shifts were observed, indicating the presence of electronic delocalization as previously demonstrated for diamagnetic compounds. Despite the large distance (>14 angstrom) between the vanadyl centers in these dimers, small dipolar interactions between the two paramagnetic ions could be determined.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Nithin Suryadevara, Athanassios K. Boudalis, Jorge Enrique Olivares Pena, Eufemio Moreno-Pineda, Artem Fediai, Wolfgang Wenzel, Philippe Turek, Mario Ruben
Summary: A mixed-ligand phthalocyanine/porphyrin yttrium(III) radical double-decker complex (DD) was synthesized using a custom-made 5,10,15-tris(4-methoxyphenyl)-20-(4-((trimethylsilyl)ethynyl)phenyl)porphyrin. Rigid tethers were used to couple two such complexes into biradicals through the trimethylsilyl functionality. The magnetic properties of DD were found to be similar to those of the parent [Y(pc)2]center dot complex in both the solid state and frozen glasses.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemical Research Methods
Athanassios K. Boudalis, Christos P. Constantinides, Nicolas Chrysochos, Raanan Carmieli, Gregory Leitus, Andreas Kourtellaris, Daniel B. Lawson, Panayiotis A. Koutentis
Summary: Compound 1 is a C3-symmetrical triradical with excellent air, moisture, and thermal stability. It adopts a propeller-like geometry and forms 1D chains along the c axis due to weak intermolecular interactions. The intramolecular ferromagnetic exchange within the spin system supports a quartet S=3/2 ground state, as confirmed by EPR and DFT calculations.
JOURNAL OF MAGNETIC RESONANCE
(2023)
Article
Chemistry, Multidisciplinary
Jack Devonport, Lauren Sully, Athanassios K. Boudalis, Storm Hassell-Hart, Matthew C. Leech, Kevin Lam, Alaa Abdul-Sada, Graham J. Tizzard, Simon J. Coles, John Spencer, Alfredo Vargas, George E. Kostakis
Summary: A dimeric Cu(II) complex was synthesized and characterized, showing a monomeric-dimeric equilibrium in solution. Addition of phenylacetylene led to the formation of a transient radical species, initiating an alkyne C-H bond activation process. The unusual C-H activation method is applicable for efficient synthesis of propargylamines within 16 hours, demonstrating structural stability and redox retention.
Article
Chemistry, Multidisciplinary
Athanassios K. Boudalis, Jorge-Enrique Olivares-Pena, Eufemio Moreno-Pineda, Artem Fediai, Wolfgang Wenzel, Philippe Turek, Mario Ruben
Summary: The FID-detected nutations of the antiferromagnetic crystal [Y(pc)(2)] show that its radical spin can be driven coherently in its magnetically condensed undeuterated phase at room temperature. In liquid-helium measurements, additional Rabi oscillations were observed, attributed to transitions within higher-multiplicity states of finite-sized chain fragments.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Jerome Robert, Philippe Turek, Matthieu Bailleul, Athanassios K. Boudalis
Summary: The study presented the development and testing of a broadband EPR spectrometer with unique CPW architecture, confirming the instrument's functionality and confirming sample stability upon deposition. Results emphasized the importance of surface effects and microwave magnetic component B1 orientation on recorded spectra line shapes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Logesh Mathivathanan, Yiannis Sanakis, Raphael G. Raptis, Philippe Turek, Athanassios K. Boudalis
Summary: A 16-line pattern for the EPR spectrum has been predicted theoretically and studied in a triangular Cu-II species, revealing the impact of Dzyaloshinskii-Moriya interactions (DMI). The study also deconvolutes two slightly different cocrystallized magnetic species for the first time in this context.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jerome Robert, Nathalie Parizel, Philippe Turek, Athanassios K. Boudalis
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2019)
Article
Chemistry, Multidisciplinary
Kaige Shi, Logesh Mathivathanan, Radovan Herchel, Athanassios K. Boudalis, Raphael G. Raptis
CHEMISTRY-SWITZERLAND
(2020)
