Syntheses, structures and properties of cadmium(II) carboxylates containing polyamine/Schiff base: Variation of coordination numbers, and molecular and crystalline architectures by changing ligands

One-pot synthesis of the building components in methanol at room temperature affords two dinuclear compounds [Cd2(L1)2(μ-tp)](ClO4)2 (1) and [Cd2(L2)2(μ-ap)(OH2)2](ClO4)2⋅2H2O⋅CH3OH (2) [L1 = N,N′-bis(3-aminopropyl)-1,2-ethanediamine, L2 = N,N′-(bis(pyridin-2-yl)benzylidene)-1,3-propanediamine, tp = terephthalate dianion, ap = adipate dianion]. The complexes 1 and2 are characterized using microanalytical, spectroscopic and other physicochemical results. Structures of 1 and2 are solved by single crystal X-ray diffraction measurements. Structural analyses reveal that each cadmium(II) center in 1/2 adopts a distorted square pyramidal/octahedral geometry with CdN4O/CdN4O2 chromophore. Terephthalate/adipate binds the metal center in 1/2 in bis(monodentate) fashion. Intermolecular NH⋯O, CH⋯O hydrogen bonds in 1 and OH⋯O, CH⋯N hydrogen bonds and π⋯π interaction in2 promote different dimensionalities. The compounds show intraligand (π–π*) fluorescence in DMF solutions at room temperature.