Rhodium and copper 6-methylpicolinate complexes. Structural diversity and supramolecular interaction study

Seven new coordination compounds of 6-methylpicolinic acid and either Rh(III) or Cu(II) are described. All the complexes show a N,O-chelation coordination mode of the 6-mepicolinic acid or 6-mepicolinate. The free oxygen atom of the carboxylic groups is implicated in the supramolecular interactions through hydrogen bonds formation in most of the compounds. Molecular aggregates, 1D and 2D networks can be obtained depending on the presence of solvent molecules in the crystal or the coordinated ligands (H2O, I or Cl). The combination of the chelating binding mode and the role of the carboxylic group of the 6-Mepic as a bridge between Cu(II) metal centers yields an unusual 1D coordination polymer of 6-methylpicolinate.103