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, {[Cd2(TPT)2L2](GM1)3/2(H2O)}∞ (1) (TPT =
terephthalate, L = 3-(2-pyridyl)pyrazole, GM1 = terephthalic acid), {[Cd(TPT)L](GM2)(H2O)2}∞ (2) (GM2 = L =
3-(2-pyridyl)pyrazole), {[Cd(TPT)L](GM3)1/2(H2O)}∞ (3) (GM3 = mesitylene), {[Cd4(TPT)4L4](GM4)7/2}∞ (4) (GM4 =
tetramethylbenzene), and {[Cd(TPT)L](GM5)1/2}∞ (5) (GM5 = 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 °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.