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Spin‐crossover between high‐spin (HS) and low‐spin (LS) states of selected transition metal ions in polynuclear and polymeric compounds is behind their use as multistep switchable materials in breakthrough electronic and spintronic devices. We report the first successful attempt to observe the dynamics of a rarely found broken‐symmetry spin state in binuclear complexes, which mixes the states [HS‐LS] and [LS‐HS] on a millisecond timescale. The slow exchange between these two states, which was identified by paramagnetic NMR spectroscopy in solutions of two spin‐crossover iron(II) binuclear helicates that are amenable to molecular design, opens a path to double quantum dot cellular automata for information storage and processing. [ABSTRACT FROM AUTHOR]

Spin‐crossover between high‐spin (HS) and low‐spin (LS) states of selected transition metal ions in polynuclear and polymeric compounds is behind their use as multistep switchable materials in breakthrough electronic and spintronic devices. We report the first successful attempt to observe the dynamics of a rarely found broken‐symmetry spin state in binuclear complexes, which mixes the states [HS‐LS] and [LS‐HS] on a millisecond timescale. The slow exchange between these two states, which was identified by paramagnetic NMR spectroscopy in solutions of two spin‐crossover iron(II) binuclear helicates that are amenable to molecular design, opens a path to double quantum dot cellular automata for information storage and processing. [ABSTRACT FROM AUTHOR]

Spin‐crossover between high‐spin (HS) and low‐spin (LS) states of selected transition metal ions in polynuclear and polymeric compounds is behind their use as multistep switchable materials in breakthrough electronic and spintronic devices. We report the first successful attempt to observe the dynamics of a rarely found broken‐symmetry spin state in binuclear complexes, which mixes the states [HS‐LS] and [LS‐HS] on a millisecond timescale. The slow exchange between these two states, which was identified by paramagnetic NMR spectroscopy in solutions of two spin‐crossover iron(II) binuclear helicates that are amenable to molecular design, opens a path to double quantum dot cellular automata for information storage and processing. [ABSTRACT FROM AUTHOR]

Here we report two new ligands from a 2,6‐bis(pyrazol‐3‐yl)pyridine family often used in spin‐crossover research and their iron(II) and cobalt(II) complexes with the metal ion trapped in the high‐spin state in solids (according to magnetometry and X‐ray diffraction data). The iron(II) complexes, however, show a gradual spin‐crossover in acetonitrile solution, as probed by the popular Evans method and an analysis of temperature dependent chemical shifts, both rooted in variable‐temperature NMR spectroscopy. The observed stabilization of the high‐spin state by the electron‐withdrawing substituents mirrors the trend previously reported for spin‐crossover iron(II) complexes of isomeric 2,6‐bis(pyrazol‐1‐yl)pyridines. [ABSTRACT FROM AUTHOR]

Keywords: broken symmetry; helicates; paramagnetic NMR; spin crossover EN broken symmetry helicates paramagnetic NMR spin crossover 1 1 1 01/12/22 20220117 NES 220117 B Spin-Crossover b . A [high spin-low spin]/[low spin-high spin] equilibrium in spin-crossover iron(II) dinuclear helicates is unravelled through paramagnetic NMR spectroscopy by Guillem Aromí, Valentin V. Novikov et al. in their Communication (e202110310). Frontispiece: Unravelling of a [High Spin - Low Spin] <-> [Low Spin - High Spin] Equilibrium in Spin-Crossover Iron(II) Dinuclear Helicates Using Paramagnetic NMR Spectroscopy. [Extracted from the article]

Frontispiz: Unravelling of a [High Spin - Low Spin] <-> [Low Spin - High Spin] Equilibrium in Spin-Crossover Iron(II) Dinuclear Helicates Using Paramagnetic NMR Spectroscopy Keywords: broken symmetry; helicates; paramagnetic NMR; spin crossover EN broken symmetry helicates paramagnetic NMR spin crossover 1 1 1 01/12/22 20220117 NES 220117 B Spin-Crossover b . Broken symmetry, helicates, paramagnetic NMR, spin crossover. [Extracted from the article]

We report the first examples of direct imidation of lactones giving the corresponding cyclic imidates via oxo/imido heterometathesis with N-sulfinylamines catalysed by a well-defined silica-supported Ti imido complex. [ABSTRACT FROM AUTHOR]

An adduct of ZnII pivalate with N-heterocyclic carbene 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene has been prepared and characterized by X-ray diffraction analysis, NMR spectroscopy and DFT calculations. The compound preserves mononuclear structure in solution and does not switch the coordination mode from normal to abnormal. [ABSTRACT FROM AUTHOR]