Poly[(6-carboxy-picolinato-κO,N,O)(µ(3)-pyridine-2,6-dicarboxyl-ato-κO,N,O:O:O)dysprosium(III)].

In the title complex, [Dy(C(7)H(3)NO(4))(C(7)H(4)NO(4))](n), one of the ligands is fully deprotonated while the second has lost only one H atom. Each Dy(III) ion is coordinated by six O atoms and two N atoms from two pyridine-2,6-dicarboxyl-ate and two 6-carboxy-picolinate ligands, displaying a bicapped trigonal-prismatic geometry. The average Dy-O bond distance is 2.40 Å, some 0.1Å longer than the corresponding Ho-O distance in the isotypic holmium complex. Adjacent Dy(III) ions are linked by the pyridine-2,6-dicarboxyl-ate ligands, forming a layer in (100). These layers are further connected by π-π stacking inter-actions between neighboring pyridyl rings [centroid-centroid distance = 3.827 (3) Å] and C-H⋯O hydrogen-bonding inter-actions, assembling a three-dimensional supra-molecular network. Within each layer, there are other π-π stacking inter-actions between neighboring pyridyl rings [centroid-centroid distance = 3.501 (2) Å] and O-H⋯O and C-H⋯O hydrogen-bonding inter-actions, which further stabilize the structure.