Dendritic Iron(III) Carbazole Complexes: Structural, Optical, and Magnetic Characteristics

This paper focuses on the synthesis, structural characterization, and study of the optical, magnetic, and thermal properties of novel architectures combining metal ions as magnetoactive centers and photoactive blocks formed by carbazole units. For this purpose, a series of azomethine complexes of th...

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Bibliographic Details
Main Authors: Matvey Gruzdev, Ulyana Chervonova, Arkadiy Kolker, Nadezhda Fomina, Ekaterina Zueva, Valerya Vorobeva, Denis Starichenko, Alexander Korolev
Format: Article
Language:English
Published: MDPI AG 2021-09-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/14/18/5445
Description
Summary:This paper focuses on the synthesis, structural characterization, and study of the optical, magnetic, and thermal properties of novel architectures combining metal ions as magnetoactive centers and photoactive blocks formed by carbazole units. For this purpose, a series of azomethine complexes of the composition [Fe(L)<sub>2</sub>]X (L = 3,6-bis[(3′,6′-di-<i>tert</i>-butyl-9-carbazol)-9-carbazol]benzoyloxy-4-salicylidene-N′-ethyl-N-ethylenediamine, X = NO<sub>3</sub><sup>−</sup>, Cl<sup>−</sup>, PF<sub>6</sub><sup>−</sup>) were synthesized by the reaction of metal salts with Schiff bases in a mixture of solvents. The UV–Vis absorption properties were studied in dichloromethane and rationalized via time-dependent density functional theory (DFT) calculations. Upon excitation at 350 nm, the compounds exhibited an intense dual fluorescence with two emission bands centered at ~445 and ~485 nm, which were assigned to <i>π</i><sub>carb</sub>–<i>π</i>* intraligand and <i>π</i><sub>carb</sub>–d<sub>Fe</sub> ligand-to-metal charge-transfer excited states. EPR spectroscopy and SQUID magnetometry revealed solid-state partial spin crossover in some compounds, and antiferromagnetic interactions between the neighboring Fe(III) ions.
ISSN:1996-1944