Remarkable Steric Effects and Influence of Monodentate Axial Ligands L on the Spin-Crossover Properties of trans-[FeII(N4 ligand)L] Complexes
| Autor: | Ilpo Mutikainen, Jean-François Létard, C. Matthias Grunert, Jinkui Tang, Hanane Zhor Lazar, Kristian Lappalainen, José Sánchez Costa, Urho Turpeinen, Philipp Gütlich, Jan Reedijk, Manuel Quesada, Graham de Ruiter, Patrick Gamez |
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| Přispěvatelé: | Leiden Institute of Chemistry, Universiteit Leiden [Leiden], Laboratory of Inorganic Chemistry, Department of Chemistry, Insitut für Anorganische und Analytische Chemie, Johannes Gutenberg - Universität Mainz (JGU), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB) |
| Rok vydání: | 2007 |
| Předmět: |
Steric effects
Denticity Tetradentate ligand Thiocyanate Mössbauer spectroscopy 010405 organic chemistry Ligand Stereochemistry [CHIM.MATE]Chemical Sciences/Material chemistry Iron complexes Pyrazole Spin crossover 010402 general chemistry 01 natural sciences 0104 chemical sciences Inorganic Chemistry chemistry.chemical_compound Crystallography chemistry Pyridine Physical and Theoretical Chemistry Dicyanamide |
| Zdroj: | Inorganic Chemistry Inorganic Chemistry, American Chemical Society, 2007, 46 (10), pp.4079-4089. ⟨10.1021/ic0624017⟩ |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic0624017 |
| Popis: | Iron(II) complexes obtained from tetradentate, rigid, linear N4 ligands have been investigated to appraise the influence of steric effects and the impact of trans-coordinated anions on the spin-transition behavior. As expected, the well-designed ligands embrace the metal center, resulting in octahedral iron(II) complexes where the basal plane is fully occupied by the pyridine/pyrazole N4 ligand, while anions or solvent molecules are exclusively axially coordinated. Precursor complexes, namely, [Fe(bpzbpy)(MeOH)2](BF4)2 (where bpzbpy symbolizes the ligand 6,6'-bis(N-pyrazolylmethyl)-2,2'-bipyridine) and [Fe(mbpzbpy)(MeOH)2](BF4)2 (where mbpzbpy symbolizes the ligand 6,6'-bis(3,5-dimethyl-N-pyrazolmethyl)-2,2'-bipyridine), have been used for the in situ preparation of a series of structural analogues via the exchange of the weakly coordinated trans methanol molecules by various anions, such as thiocyanate, selenocyanate, or dicyanamide. The magnetic properties of all seven iron(II) compounds thus obtained have been investigated. Two iron(II) complexes, i.e., [Fe(bpzbpy)(NCS)2] and [Fe(bpzbpy)(NCSe)2], exhibit gradual spin-crossover (SCO) properties typical of isolated mononuclear species with weak cooperative interaction. These two SCO materials have been studied by Mössbauer spectroscopy, and the light-induced excited spin state trapping effect has been investigated, revealing the possibility to induce the spin-transition both by temperature variation and by light irradiation. A correlation between steric/anion effect and SCO behavior is suggested. |
| Databáze: | OpenAIRE |
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