Structural and Magnetic Characterization of a Tetranuclear Copper(II) Cubane Stabilized by Intramolecular Metal Cation-pi Interactions

作者：Papadakis Raffaello; Riviere Eric; Giorgi Michel; Jamet Helene; Rousselot Pailley Pierre; Reglier Marius; Simaan A Jalila^*; Tron Thierry

来源：Inorganic Chemistry, 2013, 52(10): 5824-5830.

DOI：10.1021/ic3027545

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 Cu-4(OH)(4) cubane core, where the four copper(II) 1 centers are linked by mu(3)-hydroxo bridges. Each copper(II) ion is in a distorted square-pyramidal geometry. X-ray analysis also evidenced an unusual metal cation-pi interaction between the copper ions and phenyl substituents of the ligand. Calculations quantify the strength of this metal-pi interaction, which appears based on the density f-unctional theory method were used to 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-pyridypmethaneitnine (L-2), which only differs from L-1 by one methylene group, the same synthetic procedure led to a binuclear bis(mu-hydroxo)copper(II) complex (2) displaying intermolecular pi-pi it 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.

• 出版日期2013-5-20