English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/73734
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Title

Local coordination geometry and spin state in novel FeII complexes with 2,6-Bis(pyrazol-3-yl)pyridine-type ligands as controlled by packing forces: Structural correlations

AuthorsCraig, G. A.; Sánchez Costa, J.; Roubeau, Olivier; Teat, Simon J.; Aromí, Guillem
Issue Date2012
PublisherWiley-VCH
CitationChemistry - A European Journal 18(37): 11703-11715 (2012)
AbstractA substituted 2,6-bis(pyrazol-3-yl)pyridine (3-bpp) ligand, H4L, created to facilitate intermolecular interactions in the solid, has been used to obtain four novel FeII complexes: [Fe(H4L)2](ClO4)2·2CH3NO2·2H2O, [Fe(H4L)(H2LBF2)](BF4)·5C3H6O (H2LBF2 is an in situ modified version of H4L), [Fe(H4L)2](ClO4)2·2C3H7OH and [Fe(H4L)2](ClO4)2·4C2H5OH. Changing of spin-inactive components (solvents, anions or distant ligand substituents) causes differences to the coordination geometry of the metal that are key to the magnetic properties. Magnetic measurements show that, contrary to the previously published complex [Fe(H4L)2](ClO4)2·H2O·2CH3COCH3, the newly synthesised compounds remain in the high-spin (HS) state at all temperatures (5¿300 K). A member of the known family of FeII/3-bpp complexes, [Fe(3-bpp)2](ClO4)2·1.75CH3COCH3·1.5Et2O, has also been prepared and characterised structurally. In the bulk, this compound exhibits a gradual and incomplete spin transition near 205 K. The single-crystal structure is consistent with it being HS at 250 K and partially low spin at 90 K. Structural analysis of all these compounds reveals that the exact configuration of intermolecular interactions affects dramatically the local geometry at the metal, which ultimately has a strong influence on the magnetic properties. Along this line, the geometry of FeII in all published 3-bpp compounds of known structure has been examined, both by calculating various distortion indices (S, V, q and F) and by continuous shape measures (CShMs). The results reveal correlations between some of these parameters and indicate that the distortions from octahedral geometry observed on HS systems are mainly due to strains arising from intermolecular interactions. As previously suggested with other related compounds, we observe here that strongly HS-distorted systems have a larger tendency to remain in that state.
URIhttp://hdl.handle.net/10261/73734
DOI10.1002/chem.201200820
Identifiersdoi: 10.1002/chem.201200820
issn: 0947-6539
e-issn: 1521-3765
Appears in Collections:(ICMA) Artículos
Files in This Item:
File Description SizeFormat 
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.