Novel eclipsed 2D cadmium(II) coordination polymers with open-channel structure constructed from terephthalate and 3-(2-pyridyl)pyrazole: crystal structures, emission properties, and inclusion of guest molecules.

Five new eclipsed two-dimensional (2D) coordination polymers, Cd(2)(TPT)(2)L(2)(3/2)(H(2)O) (1) (TPT = terephthalate, L = 3-(2-pyridyl)pyrazole, GM(1) = terephthalic acid), Cd(TPT)L(H(2)O)(2) (2) (GM(2) = L = 3-(2-pyridyl)pyrazole), Cd(TPT)L(1/2)(H(2)O) (3) (GM(3) = mesitylene), Cd(4)(TPT)(4)L(4)(7/2) (4) (GM(4) = tetramethylbenzene), and Cd(TPT)L(1/2) (5) (GM(5) = naphthalene), have been synthesized and characterized by X-ray diffraction. All the five complexes take the similar eclipsed 2D open-channel framework with different guest molecules included in the cavities of their channels. TGA analysis indicates that the eclipsed open-channel frameworks are thermally stable up to 300 degrees C. The porous property of the 2D framework of 5 was also investigated by the XRPD technique, which indicated that the guest molecules included in the open-channel frameworks are removable and the framework is maintained after the removal of the guest molecules. Moreover, complexes 1-5 also display strong blue emission in the solid state.