Property Studies Of A Series Of Metal-Organic Frameworks Assembled By Indium Halides And H₃DPPC Ligand

Metal-organic frameworks(MOFs), as an emerging inorganic-organic hybrid material with a porous structure, have received a widely attention in adsorptive separation due to their tunable porosity and functional surface, which have been considered as an extraordinarily potential adsorbent. Tuning pore size through different kinds of ligands and ―designing‖ frameworks toward particular applications have always been a hotspot in this area.As a new type of absorbents, MOFs are particularly flexible in structure, which has long been seen as ―tunable‖ and ―designable‖ to meet special applications and this ―design‖ is always accessed through changing the type of organic linkers with a similar geometric structure, such as extending/shortening a linker by adding/deleting benzene fragments of its structure, and furthermore tuning the pore size. However, this traditional method of changing ligands cannot tune the pore more precisely and subtly than nanometer. In this article, we report a simple and novel strategy to tune the pore size of MOFs by introducing different halides into the frameworks of MOFs. Three novel MOFs—In-DPPC-Cl, In-DPPC-Br and In-DPPC-I have been successfully assembled with a variety of indium halides and H3 DPPC linkers under solvothermal condition. They are isostructural and exhibit 1D double-walled straight channels. The pore sizes can be tuned from 11.61 ? to 13.21 ?, due to the different radii of the halogen ions in the pores.In this article, the synthesis and structures of these three MOFs were first studied, then further investigates of the adsorption in both gas and liquid phases were carried out:(i) The N2 adsorption studies confirm that the periodical variation in maximum adsorption capacity of the three MOFs are in good agreement with their changes in pore sizes;(ii) in gas phase, the components also reveal high adsorption capacities for CO2, CH4, C2H6 and C3H8;(iii) due to the difference of halogen ions in the pore, the respective adsorption capacity of In-DPPC-Cl for cationic dyes such as methylene blue(MB) and In-DPPC-Br for I2 molecules in liquid phase have also been preliminary studies.