title: Dinuclear Cu(II) complexes of isomeric bis-(3-acetylacetonate)benzene ligands: synthesis, structure, and magnetic properties.
abstract: Highly versatile coordinating ligands are designed and synthesized with two β-diketonate groups linked at the carbon 3 through a phenyl ring. The rigid aromatic spacer is introduced in the molecules to orient the two acetylacetone units along different angles and coordination vectors. The resulting para, meta, and ortho bis-(3-acetylacetonate)benzene ligands show efficient chelating properties toward Cu(II) ions. In the presence of 2,2'-bipyridine, they promptly react and yield three dimers, 1, 2, and 3, with the bis-acetylacetonate unit in bridging position between two metal centers. X-ray single crystal diffraction shows that the compounds form supramolecular chains in the solid state because of intermolecular interactions. Each of the dinuclear complexes shows a magnetic behavior which is determined by the combination of structural parameters and spin polarization effects. Notably, the para derivative (1) displays a moderate antiferromagnetic coupling (J = -3.3 cm(-1)) along a remarkably long Cu···Cu distance (12.30 Å).
authors.affiliation: Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche and Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali, Dipartimento di Scienze Chimiche, Università di Padova, Via F. Marzolo, 1-35131, Padova, Italy. marzio.rancan@unipd.it
authors.forename: Marzio
authors.initials: M
authors.lastname: Rancan
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dolmella
authors.forename: Roberta
authors.initials: R
authors.lastname: Seraglia
authors.forename: Simonetta
authors.initials: S
authors.lastname: Orlandi
authors.forename: Silvio
authors.initials: S
authors.lastname: Quici
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Sorace
authors.forename: Dante
authors.initials: D
authors.lastname: Gatteschi
authors.forename: Lidia
authors.initials: L
authors.lastname: Armelao
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D003300:Copper / Q000737:chemistry*; D007536:Isomerism; D060328:Magnetic Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D001555:Benzene Derivatives; D009942:Organometallic Compounds; D003300:Copper