Synthesis and characterization of CPO-1;: three-dimensional coordination polymers with 2,6-naphthalenedicarboxylate (ndc) ligands [M(ndc)(H2O)], M = Mn(II), Zn(II) or Cd(II)

A new type of a three-dimensional coordination polymer [M(ndc)(H2O)] (M = Mn(II), Zn(II) or Cd(II), ndc = 2,6-naphthalenedicarboxylate) has been synthesized by hydrothermal methods. The isostructural compounds denoted CPO-1 (coordination polymer of Oslo number 1) contains infinite pseudochains of isolated polyhedra running along [00 1] connected by carboxylate moieties in the [100] direction. The carboxylate bridges adopt a syn-anti conformation. In CPO-1-Mn and CPO-1-Zn the metal atoms are five-coordinated by four carboxylato oxygens and one water molecule, while in CPO-1-Cd, the Cd atoms are seven-coordinated involving two long additional bonds to carboxylate oxygens. The magnetic susceptibility measurements on CPO-1-Mn indicated rather weak antiferromagnetic interactions between the Mn(II) atoms. CPO-1-Mn and CPO-1-Zn are thermally stable to about 400 degreesC. In the range 200-400 degreesC a dehydrated variant is stable. The unit cell dimensions of the high temperature variant of CPO-1-Zn clearly indicate a structural relationship to the as-synthesized material. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.