Structural and luminescent properties of a series of Cd(II) pyridyl benzimidazole complexes that exhibit extended three-dimensional hydrogen bonded networks

Five new coordination complexes, [CdI2(3-PyBim)](H2O)3 (1), [Cd(SO4)(3-PyBim)(H2O)4] (2), [CdCl2(4-PyBim)2(H2O)2] (3), [CdBr2(4-PyBim)2(H2O)2] (4) and [CdI2(4-PyBim)2(H2O)2] (5) [3-PyBim=2-Pyridin-3-yl-1H-benzoimidazole, 4-PyBim=2-Pyridin-4-yl-1H-benzoimidazole], were obtained under hydrothermal conditions and characterized by single crystal X-ray diffraction, IR, elemental analysis, and powder X-ray diffraction. All of the complexes have mononuclear structures. Among the crystal structures of these complexes, there exist a variety of intermolecular hydrogen bonding interactions and π⋯π interactions, which further extend to a 3-D supramolecular architecture. The solid state photoluminescent properties of 1–5 vary with the electronegativity of the coordination anion. Additionally, the thermogravimetric analyses of these complexes are discussed.