Two 3D Supramolecular Cadmium(II) Coordination Polymers Derived from Semi-rigid Bis(2-methylbenzimidazole) and Different Dicarboxylate Ligands

Abstract

Two cadmium(II) coordination polymers, [Cd(L)(nda)(H2O)·0.75H2O] n (1) and [Cd(L)(tbta)(H2O)] n (2) (L = 1,3-bis-(2-methylbenzimidazol-1-ylmethyl)benzene, H2nda = 2,6-naphthalenedicarboxylic acid, H2tbta = tetrabromoterephthalic acid), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction and powder X-ray diffraction analysis. Both complexes exhibit 2D (6,3) honeycomb-like structures. Complex 1 is further extended into a twofold interpenetrating 3D 4,4-connected mog supramolecular architecture with point symbol of {4.64.8}2{42.62.82} via classical O–H···O hydrogen bonding interactions, while 2 displays a 3D supramolecular framework through π–π stacking interactions. The fluorescence properties and thermal stability of the two complexes were investigated.