Hydrogen-bond directed 2D → 3D polythreading of a new luminescent Cd(II) coordination polymer

Solvothermal reactions of Cd(II) salts with biphenyl-3,4′,5-tricarboxylic acid (H3L) and melamine (MA) afford a new coordination polymer, namely [Cd3(L)2(MA)2(H2O)2]n (1). Single crystal X-ray analysis reveals that compound 1 displays a new 2D → 3D polythreaded motif directed by intermolecular hydrogen bonds, in which large opened windows of each (3,6)-connected layer are threaded by two dangling MA molecules from adjacent layers in the opposite direction. In addition, the luminescent property of 1 was also investigated in the solid state at room temperature.