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A series of bis-iminonitroxide diradical derivatives of different lengths and geometry have been prepared that incorporate a conjugated phenylene-ethynylene bridge as a rigid spacer. This paper describes the synthesis of these new components and their main characterizations. An unexpected singlet ground state and substituent effects on the singlet-triplet gap have been found for substituted "m-phenylene"-based diradicals. The effects of the pi-conjugation on the intramolecular through-bond spin coupling have been investigated by changing the length of the spacer within linear derivatives. The EPR studies demonstrate the intramolecular magnetic coupling between the radical spins within all compounds. This result is very attractive and unusual, given the large distance between the radicals from 15 A in the dimer to 36 A in the pentamer.
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http://dx.doi.org/10.1021/jo034723n | DOI Listing |
Chem Sci
August 2025
School of Physics, Nanjing University of Science and Technology Nanjing 210094 China
The role of electronic spin in electrocatalysis has led to the emerging field of "spin-dependent electrocatalysis". While spin effects in individual active sites have been well understood, spin coupling among multiple sites remains underexplored in electrocatalysis, which will bring forth new active sites and mechanisms. In this work, we propose a general theory to understand the spin coupling in electrocatalysis.
View Article and Find Full Text PDFAdv Mater
September 2025
School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Molecular spin systems that can be chemically tuned, coherently controlled, and readily integrated within devices remain central to the realization of emerging quantum technologies. Organic high-spin materials are prime candidates owing to their similarity in electronic structure to leading solid-state defect-based systems, light element composition, and the potential for entanglement and qubit operations mediated through spin-spin exchange. However, the inherent instability of these species precludes their rational design, development, and application.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Layered van der Waals (vdW) materials, characterized by their interlayer vdW gaps, offer exceptional tunability of magnetic properties via intercalation chemistry. A wide range of magnetic behaviors have been observed in nonmagnetic transition-metal dichalcogenides intercalated with magnetic atoms. Beyond the incorporation of magnetic ions, we propose the controlled alkali-ion intercalation of intrinsic vdW magnets as a strategy to probe and manipulate spin populations and exchange interactions within individual magnetic layers.
View Article and Find Full Text PDFMAGMA
September 2025
Institute of Diagnostic and Interventional Radiology, School of Medicine and Health, Technical University of Munich, Munich, Germany.
Purpose: To enable accelerated Bloch simulations by enhancing the open-source multi-purpose MRI simulation tool JEMRIS with graphic processing units (GPU) parallelization.
Methods: A GPU-compatible version of JEMRIS was built by shifting the computationally expensive parallelizable processes to the GPU to benefit from heterogeneous computing and by adding asynchronous communication and mixed precision support. With key classes reimplemented in CUDA C++, the developed GPU-JEMRIS framework was tested on simulations of common MRI artifacts in numerical phantoms.
J Chem Theory Comput
September 2025
Institute of Physical Chemistry, University of Freiburg, Albertstraß e 21, 79104 Freiburg, Germany.
The accurate computation of high-spin/low-spin gaps remains a challenging task in computational chemistry, with significant implications for both theoretical studies and experimental applications. In this work, we present an exchange-dedicated perturbation theory (EDPT2) that allows an efficient calculation of exchange couplings in magnetic systems. Our approach builds on a previously developed second-order perturbative scheme based on de Loth's formalism but refines the treatment of singlet wave functions by explicitly incorporating ionic determinants in the zeroth-order description.
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