Synthesis and characterization of a pair of temperature and cosolvent-dependent Zn(II)-organic frameworks containing a novel discrete single-walled Zn(II)-organic coordination polymer nanotube

A pair of temperature and cosolvent-controlled assemblies of one dimensional (1-D) and two dimensional (2-D) Zn(II)-organic frameworks (ZOFs] based on 5-iodoisophthalic acid (H2IIP) and an auxiliary flexible ligand, 1,4-bis(triazol-1-ylmethyl)benzene (bbtz) with different structures, has been rationally designed and successfully synthesized. Results show that when the reaction was carried out under ambient condition, the novel discrete single-walled Zn(II)-organic coordination polymer nanotube {[Zn(IIP)(bbtz)(H2O)]·H2O}n (SWCPNT-1), which shows a fascinating 3-D supramolecular interdigitated columnar microporous architecture supported by face to face π⋯π stacking interactions and hydrogen bonds, was generated, whereas under solvothermal condition at 120 °C, an interesting 3-D-polycatenated array of layers, [Zn(IIP)(bbtz)] (2), which further extends into a threefold-interpenetrated 3-D supramolecular mesoporous framework with 1-D channels (ca. 3.46 × 1.54 nm2) through C–I⋯O halogen bonds would be obtained. Interestingly, the reversible in situ rapid rehydration from static air is significantly observed in the discrete SWCPNT-1, revealing its potential application as water absorbent and sensing material. The dehydrated SWCPNT-1 shows selective gas adsorption of CO2 over N2. Luminescent studies show that SWCPNT-1, dehydrated SWCPNT-1, and 2 exhibit blue fluorescence in the solid state. The water molecules in SWCPNT-1 affect its fluorescent property.