Metal(II)-organic coordination polymers with two distinct atropisomeric building units from an axially prochiral inner salt through interchain C–H⋯X hydrogen bonds (X = O, Cl; metal = cobalt, nickel)

Two isostructural photoluminescent metal–organic coordination polymers, namely, [M(H-mpypdc)(Cl)(H2O)3]n (mpypdc = 2,6-dimethyl-4-(pyridin-4-yl)pyridine-3,5-dicarboxylate; M = Co (2) and Ni (3)), were synthesized from H2mpypdc (1), and characterized by single crystal X-ray analyses. New ligand 1 is an inner salt. In the metal–organic coordination polymeric chains, two distinct S- and R-atropisomeric units are generated from the axially prochiral 1 through C–H⋯X (X = O, Cl) hydrogen bonds. There have interesting 2D supramolecular networks [M(Cl)(H2O)2]n in the crystal structures of title compounds. The photoluminescence of new compounds are also investigated in solid state at ambient temperature.

Graphical abstractTwo distinct S- and R-atropisomeric building units from an axially prochiral inner salt through C–H⋯X (X = O, Cl) hydrogen bonds co-exist in the 1-D coordination polymer. And an interesting hydrogen-bonded [M2+(Cl)(H2O)2]n supramolecular network exists in the crystal structures of title compounds.Figure optionsDownload full-size imageDownload as PowerPoint slide