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Electron paramagnetic resonance spectra of homoleptic and mixed-ligand molybdenum tris(dithiolene) complex anions [Mo(tfd)(m)(bdt)(n)](-) (n + m = 3; bdt = S(2)C(6)H(4); tfd = S(2)C(2)(CF(3))(2)) reveal that the spin density has mixed metal-ligand character with more ligand-based spin for [Mo(tfd)(3)](-) and a higher degree of metal-based spin for [Mo(bdt)(3)](-): the magnitude of the isotropic (95,97)Mo hyperfine interaction increases continuously, by a factor of 2.5, on going from the former to the latter. The mixed complexes fall in between, and the metal character of the spin increases with the bdt content. The experiments were corroborated by density functional theory computations, which reproduce this steady increase in metal-based character.
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http://dx.doi.org/10.1021/ic201047k | DOI Listing |
Inorg Chem
August 2025
Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart D-70569, Germany.
The spin dynamics of a tris(dithiolate)vanadium complex dianion and perdeutero-tetraphenylarsonium cation, (AsPh4-)[V(mnt)], composed of spin-free and weakly magnetic nuclei are investigated in an analogously composed solvent system, CDCl/ClCCN (4:1). This gives the longest reported coherence times for a transition-metal-based spin in deuterated solvents with a of 164(4) ms, and a of 60(2) μs. Dynamic decoupling more than doubled , resulting in = 136(13) μs.
View Article and Find Full Text PDFAdv Sci (Weinh)
August 2025
School of Chemical Engineering and Technology, Sun Yat-Sen University, Zhuhai, Guangdong, 519082, P. R. China.
Regulating spin polarization has been recognized as a promising strategy to improve the catalytic performance across various catalytic domains, since the reaction barriers can be directly influenced by the spin state. However, the existing approaches to modulating the spin polarization of active centers mainly focus on the metal-based catalysts, and those for the earth-abundant carbon-based metal-free catalysts (CMFCs) are rarely reported. Here, a topological defect engineering strategy is proposed to regulate the spin polarization by introducing pentagon defects on the edge of CMFCs.
View Article and Find Full Text PDFPhys Rev Lett
July 2025
Cornell University, School of Applied and Engineering Physics, Ithaca, New York 14853 USA.
We present an optical technique for suppressing relaxation in alkali-metal spins using a single off-resonant laser beam. The method harnesses a physical mechanism that synchronizes Larmor precession in the two hyperfine manifolds, protecting magnetic coherence from relaxation caused by spin-exchange and other hyperfine-changing collisions. We experimentally demonstrate up to a ninefold reduction in decoherence of warm cesium vapor, achieving simultaneous protection from both spin-exchange relaxation and partial depolarization from coated cell walls.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
School of Nanoscience and Materials Engineering, Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Henan University, Kaifeng 475004, China.
Using a weaker ligand field thiaporphyrin macrocycle (STTP) as a heme-like ligand, we succeeded in the isolation of an unprecedented complete series of {CoNO} ( = 9 and 10 in the Enemark-Feltham notation) and a (STTP){CoNO} species. Specifically, electrochemical or chemical reduction of a {CoNO} ( = 1/2) species by potassium graphite (KC) results in first ligand-based reduction leading to a {CoNO} moiety antiferromagnetically coupled to a thiaporphyrin dianionic radical yielding an overall = 0 ground state, and subsequent metal-based reduction affording an = 1/2 complex comprised of a genuine {CoNO} unit ligated by a thiaporphyrin radical. Multiple analytical and spectroscopic measurements using SXRD, IR, NMR, SQUID, and EPR coupled to detailed DFT calculations support the assignment of a high-spin Co center in {CoNO} and (STTP){CoNO} and a high spin Co center in {CoNO}.
View Article and Find Full Text PDFChemistry
September 2025
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China.
Harnessing secondary energy sources for water electrolysis to generate "green hydrogen" is instrumental in constructing a zero-carbon-emission hydrogen value chain. However, the anodic oxygen evolution reaction (OER) presents a bottleneck due to its complex four-step proton-coupled electron transfer process. Investigation of high-performance anodic OER catalysts has developed into a hot research field.
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