High-Temperature Spin Crossover in Iron(II) Complexes with 2,6-Bis(1 H-imidazol-2-yl)pyridine

Ludmila G Lavrenova; Olga G Shakirova; Evgeniy V Korotaev; Svetlana V Trubina; Alexsei Ya Tikhonov; Irina A Os'kina; Sergey A Petrov; Konstantin Yu Zhizhin; Nikolay T Kuznetsov

doi:10.3390/molecules27165093

High-Temperature Spin Crossover in Iron(II) Complexes with 2,6-Bis(1 H-imidazol-2-yl)pyridine

Molecules. 2022 Aug 10;27(16):5093. doi: 10.3390/molecules27165093.

Authors

Ludmila G Lavrenova¹, Olga G Shakirova^{1

2}, Evgeniy V Korotaev¹, Svetlana V Trubina¹, Alexsei Ya Tikhonov³, Irina A Os'kina³, Sergey A Petrov⁴, Konstantin Yu Zhizhin⁵, Nikolay T Kuznetsov⁵

Affiliations

¹ Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Academic Lavrentyev Avenue 3, 630090 Novosibirsk, Russia.
² Department of Chemistry and Chemical Technologies, Faculty of Machinery and Chemical Technologies, Federal State Budget Institution of Higher Education, Komsomolsk-na-Amure State University, Lenin Avenue 27, 681013 Komsomolsk-on-Amur, Russia.
³ N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry Siberian Branch, Russian Academy of Sciences, Academic Lavrentyev Avenue 9, 630090 Novosibirsk, Russia.
⁴ Institute of Solid State Chemistry, Siberian Branch, Russian Academy of Sciences, Kutateladze Street 18, 630128 Novosibirsk, Russia.
⁵ Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii Avenue 31, 119991 Moscow, Russia.

Abstract

Novel iron(II) coordination compounds containing a ligand 2,6-bis(1H-imidazol-2-yl)pyridine (L), having such a composition as [FeL₂]SO₄·0.5H₂O, [FeL₂]Br₂·H₂O, [FeL₂](ReO₄)₂, [FeL₂]B₁₀H₁₀∙H₂O, [FeL₂]B₁₂H₁₂∙1.5H₂O had been synthesized and studied using UV-Vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mössbauer spectroscopy methods, as well as X-ray diffraction and static magnetic susceptibility methods. The analysis of the μ_eff(T) dependence in the temperature range of 80-600 K have shown that all the obtained complexes exhibit a high-temperature spin crossover ¹A₁ ↔ ⁵T₂.

Keywords: 2,6-bis(1H-imidazol-2-yl)pyridine; EXAFS; IR; Mössbauer; UV-Vis (diffuse reflectance) spectroscopy methods; X-ray diffraction analysis; iron(II) complexes; spin crossover.

Abstract

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