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Room temperature spin crossover properties in a series of mixed-anion Fe(NH2trz)3(BF4)2−x(SiF6)x/2 complexes.

Authors :
Yang, Xinyu
Enriquez-Cabrera, Alejandro
Jacob, Kane
Coppel, Yannick
Salmon, Lionel
Bousseksou, Azzedine
Source :
Dalton Transactions: An International Journal of Inorganic Chemistry. 4/21/2024, Vol. 53 Issue 15, p6830-6838. 9p.
Publication Year :
2024

Abstract

A series of mixed-anion Fe(NH2trz)3(BF4)2−x(SiF6)x/2 spin crossover complexes is obtained modifying the reaction time but also using an increase amount of tetraethyl orthosilicate as the source for the production and the incorporation of SiF62− competing with the BF42− anions present in the mother solution. The increase of the SiF62− anion inclusion to the detriment of the BF4− counterpart induces a shift of the temperature transition toward high temperatures leading to interesting bistability properties around room temperature with T1/2 spanning from 300 K to 325 K. Moreover, the implementation of a solid–liquid post synthetic modification approach from the Fe(NH2trz)3(BF4)2 parent complex with identical TEOS proportions and under certain experimental conditions lead systematically to the same Fe(NH2trz)3(BF4)1.2(SiF6)0.4 composition. This compound presents an abrupt spin crossover behaviour with a narrow hysteresis loop just above room temperature (320 K), which is stable under thermal cycling and along time with no specific storage conditions. Such crystalline powder sample incorporates homogeneous rod-shaped particles whose formation and physical properties can be followed simultaneously using infra-red spectroscopy, dynamic light scattering (DLS), transmission electronic microscopy (TEM) and optical reflectance. The observation of a stabilized single ca. 800 nm population of mixed-anion particles starting from insoluble various sizes (from nano- to microscale) Fe(NH2trz)3(BF4)2 particles supports the key role of the solvent (water molecules) on the separation, the reactivity and the reorganization of the 1D iron-triazole chains forming the packing of the structure. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
14779226
Volume :
53
Issue :
15
Database :
Academic Search Index
Journal :
Dalton Transactions: An International Journal of Inorganic Chemistry
Publication Type :
Academic Journal
Accession number :
176611114
Full Text :
https://doi.org/10.1039/d4dt00267a