Spin transitions in ferric catecholate complexes mediated by outer-sphere counteranions.
Maxim G ChegerevOleg P DemidovPavel N Vasil'evNikolay EfimovStanislav P KubrinAndrey StarikovValery G VlasenkoAlexander V PiskunovSvetlana ShapovalovaAlexander GudaYury RusalevAlexander SoldatovPublished in: Dalton transactions (Cambridge, England : 2003) (2022)
A family of ionic ferric catecholate complexes 1-4 bearing a disubstituted 3,6-di- tert -butyl-catecholate ligand (3,6-DBCatH 2 ) and tetradentate tris(2-pyridylmethyl)amine (TPA) was prepared and its spin transitions were investigated. Variation of the outer-sphere counteranions (PF 6 , BPh 4 , ClO 4 , BF 4 ) is accompanied by changes in the magnetic behavior of the compounds under consideration. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction analysis at 100 K and 293 K. The complexes were characterized by the occurrence of a thermally induced spin-crossover process in the solid state with different degrees of completeness, which was confirmed by the comprehensive spectroscopic investigation (EPR, magnetic susceptibility, Mössbauer, and XAS) of the isolated compounds. Complex 4 containing BF 4 anions was found to demonstrate valence tautomeric transition along with spin-crossover. This finding makes compound 4 the first salt-like mononuclear ferric catecholate complex exhibiting valence tautomerism.
Keyphrases
- solid state
- room temperature
- density functional theory
- single molecule
- ionic liquid
- transition metal
- open label
- iron deficiency
- molecularly imprinted
- high resolution
- risk assessment
- molecular docking
- diabetic rats
- atomic force microscopy
- randomized controlled trial
- placebo controlled
- oxidative stress
- peripheral blood
- escherichia coli
- magnetic resonance
- benign prostatic hyperplasia
- stress induced
- high speed