Crystal structure of poly[(4-aminopyridine-kappa N)(N, N-dimethylformamide-kappa O)(mu(3)-pyridine-3,5-dicarboxylato-kappa N-3: O-3 : O-5) copper(II)]

The title compound, [Cu(C7H3NO4)(C5H6N2)(C3H7NO](n), is an amino-functionalized chiral metal-organic framework with (10,3)-a topology. It has been constructed via the assembly of the achiral triconnected pyridine-3,5-dicarboxylate (3,5-PDC) building block and a triconnected Cu-II atom. Each Cu-II ion is coordinated by two O atoms and one N atom, respectively, of three crystallographically independent 3,5-PDC ligands. The square-pyramidal (CuN2O3) coordination geometry of the Cu-II ion is completed by an N atom of a terminal 4-aminopyridine (4-APY) ligand and the O atom of a terminal N, N-dimethylformamide (DMF) ligand to give a triconnected 'T'-shaped secondary building unit, which becomes trigonal in the resulting (10,3)-a topology. In the three-dimensional structure, weak N-H center dot center dot center dot O hydrogen bonds are observed in which the donor N-H groups are provided by the 4-APY ligands and the acceptor O atoms are provided by the non-coordinating carboxylate O atoms of the 3,5-PDC ligands.