title: Structural and magnetic characterization of a tetranuclear copper(II) cubane stabilized by intramolecular metal cation-π interactions.
abstract: A novel tetranuclear copper(II) complex (1) was synthesized from the self-assembly of copper(II) perchlorate and the ligand N-benzyl-1-(2-pyridyl)methaneimine (L(1)). Single-crystal X-ray diffraction studies revealed that complex 1 consists of a Cu4(OH)4 cubane core, where the four copper(II) centers are linked by μ3-hydroxo bridges. Each copper(II) ion is in a distorted square-pyramidal geometry. X-ray analysis also evidenced an unusual metal cation-π interaction between the copper ions and phenyl substituents of the ligand. Calculations based on the density functional theory method were used to quantify the strength of this metal-π interaction, which appears as an important stabilizing parameter of the cubane core, possibly acting as a driving parameter in the self-aggregation process. In contrast, using the ligand N-phenethyl-1-(2-pyridyl)methaneimine (L(2)), which only differs from L(1) by one methylene group, the same synthetic procedure led to a binuclear bis(μ-hydroxo)copper(II) complex (2) displaying intermolecular π-π interactions or, by a slight variation of the experimental conditions, to a mononuclear complex (3). These complexes were studied by X-ray diffraction techniques. The magnetic properties of complexes 1 and 2 are reported and discussed.
authors: Aix Marseille Université, CNRS, ISM2 UMR 7313, 13397 Marseille, France.
authors: Raffaello
authors: R
authors: Papadakis
authors: Eric
authors: E
authors: Rivière
authors: Michel
authors: M
authors: Giorgi
authors: Hélène
authors: H
authors: Jamet
authors: Pierre
authors: P
authors: Rousselot-Pailley
authors: Marius
authors: M
authors: Réglier
authors: A Jalila
authors: AJ
authors: Simaan
authors: Thierry
authors: T
authors: Tron
mesh_terms: D002412:Cations / Q000138:chemical synthesis / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D060526:Magnetic Fields; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature
chemical_list: D002412:Cations; D009942:Organometallic Compounds; D003300:Copper