Dinuclear Cu(II) complexes of isomeric bis-(3-acetylacetonate)benzene ligands: synthesis, structure, and magnetic properties

Inorg Chem. 2012 May 7;51(9):5409-16. doi: 10.1021/ic3003806. Epub 2012 Apr 19.

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).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzene Derivatives / chemistry*
  • Chemistry Techniques, Synthetic*
  • Copper / chemistry*
  • Isomerism
  • Magnetic Phenomena*
  • Models, Molecular
  • Molecular Conformation
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry*

Substances

  • Benzene Derivatives
  • Organometallic Compounds
  • Copper