Unravelling of a [High Spin-Low Spin] ↔ [Low Spin-High Spin] Equilibrium in Spin-Crossover Iron(II) Dinuclear Helicates Using Paramagnetic NMR Spectroscopy

Dmitry Yu Aleshin; Rosa Diego; Leoní A Barrios; Yulia V Nelyubina; Guillem Aromí; Valentin V Novikov

doi:10.1002/anie.202110310

Unravelling of a [High Spin-Low Spin] ↔ [Low Spin-High Spin] Equilibrium in Spin-Crossover Iron(II) Dinuclear Helicates Using Paramagnetic NMR Spectroscopy

Angew Chem Int Ed Engl. 2022 Jan 17;61(3):e202110310. doi: 10.1002/anie.202110310. Epub 2021 Nov 25.

Authors

Dmitry Yu Aleshin¹, Rosa Diego², Leoní A Barrios², Yulia V Nelyubina^{1

3}, Guillem Aromí², Valentin V Novikov^{1

3}

Affiliations

¹ A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova str. 28, 11999, Moscow, Russia.
² Department de Quimica Inorganica and IN2UB, Universitat de Barcelona, Diagonal 647, 08028, Barcelona, Spain.
³ Moscow Institute of Physics and Technology, Institutskiy per. 9, 141700 Dolgoprudny, Moscow region, Russia.

PMID: 34757659
DOI: 10.1002/anie.202110310

Abstract

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.

Keywords: broken symmetry; helicates; paramagnetic NMR; spin crossover.

Abstract

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