Unique topological motifs in two Cd(II)-coordination polymers: mutual-embedded 2D bilayers, 3D polythreaded structures, self-penetrated networks and 2D -> 2D interpenetrated homochiral bilayers

Two unique entangled Cd(II) coordination polymers, {[Cd-2(m-pdoa)(2)(dpa)(3)(H2O)]}(n) (1) and {[Cd(m-pdoa)(bpp) (H2O)]center dot 2H(2)O} n (2) (m-H(2)pdoa = 1,3-phenylenedioxy diacetic acid, dpa = 4,4'-dipyridylamine; bpp = 1,3-di.4-pyridyl)propane), have been modulated using flexible/semi-rigid mixed aromatic carboxylate and pyridine derivative ligands and characterized using elemental analysis, infrared spectra (IR), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 shows the first topological motifs of mutual-embedded bilayers originating from two reverse 2D 4(4)-sql layers with 1D single side arms in an alternating fashion, and thus affording a 3D polythreaded structure featuring poly-pseudo-rotaxane that exhibits a new 3D (3,3,3,3,3,5,5,5)-connected self-penetrated H-bonding net. Whereas 2 displays rare 2D -> 2D homochiral interpenetrated layers propagating from 4(4)-sql chiral layers. Additionally, thermal stabilities and luminescent properties for 1 and 2 were also discussed.