Two cobalt(II) 5-aminoisophthalate complexes and their stable supramolecular microporous frameworks

Inorg Chem. 2006 Aug 7;45(16):6276-81. doi: 10.1021/ic0602244.

Abstract

Two stable supramolecular microporous cobalt(II) polymers, namely [Co(HAIP)2]n.3nH2O (1) and [Co(AIP)(H2O)]n (2), AIP = 5-aminoisophthalate, were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, and variable-temperature magnetic susceptibility measurements. The two complexes are constructed from the same Co2(CO2)2 SBU, which is extended into a 1D chain in 1 and a 2D layer in 2. As a result, 1 and 2 are 2D and 3D coordination polymers, respectively. The 3D supramolecular network of complex 1 is held up by strong hydrogen bonds formed between carboxylate groups and shows very high stability when the free H2O molecules are removed, indicating an extraordinarily stable H-bonding system. Upon water ligands being liberated, complex 2 becomes a stable microporous solid with coordination-unsaturated Co centers. The behavior of the susceptibility curve of 1 suggests the occurrence of an interesting intrachain antiferromagnetic coupling between the Co(II) ions and the presence of a significant orbital contribution, whereas the features of 2 indicate an antiferromagnetic coupling with T(N) = 3.5 K and a long-range antiferromagnetic order with a field-induced magnetic transition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cobalt / chemistry*
  • Crystallography, X-Ray
  • Phthalic Acids / chemistry*
  • Polymers / chemistry*
  • Porosity

Substances

  • Phthalic Acids
  • Polymers
  • Cobalt
  • 5-aminoisophthalic acid