A New Cobalt(II)-Layered Network Based on Phenyl(carboxymethyl) Phosphinate

In the presence of 4,4'-bipyridine (4,4'-bipy) and Co-II metal ions, a bifunctional phosphinate-carboxylate ligand, phenyl(carboxymethyl) phosphinate (pcc), forms a new polymeric metal-organic framework (MOF), [[Co(pcc)(4,4'-bipy)(H2O)]-(H2O)(1.5)](n) (1). The structure consists of 2D slabs connected by solvent water molecules with cobalt metal atoms in two different coordination environments. The temperature-dependent X-ray powder diffraction analysis of 1 shows the formation of dehydrated phases in the range 120-180 degrees C. The dehydration rehydration process is reversible. The overall magnetic behaviour of complex 1 is dominated by single ion effects with only weak exchange coupling interactions, due to the syn/anti conformation of the Co-O-C-O-Co path.