Coordination polymers with chelidonate (4-oxo-4H-pyran-2,6-dicarboxylate) anions and dmso: [Zn(chel)(dmso)2] and linkage isomers of [Co(chel)(dmso)(OH2)3]·H2O

Recrystallization from dmso of the previously prepared compound [Co(chel)(H2O)4] (chel = 4-oxo-4H-pyran-2,6-dicarboxylate), led to the new one-dimensional coordination polymers 1a and 1b, which are linkage isomers of formula [Co(chel)(dmso)(OH2)3]·H2O. Also the recrystallization from dmso of the previously prepared [Zn(chel)(H2O)2] allow the isolation of the one-dimensional coordination polymer [Zn(chel)(dmso)2] (2). [Co(chel)(H2O)4] was characterized by elemental analysis, IR and electronic spectroscopy, magnetic measurements at room temperature and thermogravimetric analysis. X-ray single crystal diffraction of 1a, 1b and 2 showed the coordinative behavior of the chelidonate ligand in each compound as well as the different participation of this ligand in the corresponding metallosupramolecular organization.