Design, Synthesis And Gases Sorption Performances Of Acylamide-modified Porous Coordination Polymer

Porous coordination polymers (PCPs) as new porous materials are formed byindependent assembly formed of metal ions (or metal ion clusters) and organicligands. Because of these materials contain a certain size, shape cavity and theperiodic crystal coordination polymer network structure, it is also known metal-organic framework compounds (MOFs). Compared with the conventional porousmaterial, its can be adjusted in many aspects, such as specific surface area, porevolume, pore size, etc. Even by modifying portions of which have unique properties,there is a huge potential in terms of storage and separation of CO2, CH4and othergases of small molecules. With the rapid development of social, energy crisis andglobal warming increasing cause for concern and attention. Porous coordinationpolymer materials have being taken seriously due to their own advantage.In this paper, we have design and synthesis three organic ligand (H4BDPT,H4NDED and H4BDPO), which have high symmetry, modified by acylamide group oralkynyl group, four carboxylic acidacid. Each of ligand and paddle wheel-shaped[Cu2(COO)4] secondary structural unit under certain conditions, by self-assembly, gotthree NbO-type topology, non-interspersed porous coordination polymers[Cu2(BDPT)(H2O)2]n,[Cu2(NDED)(H2O)2]nand [Cu2(BDPO)(H2O)4]n. We use aseries of means to characterize and study their structures and gas properties. All ofthe PCPs has a large BET specific surface area. After removal of the guest molecules,only [Cu2(BDPT)(H2O)2]nporous skeletal structure partially collapsed. Theacylamide-modified [Cu2(BDPT)(H2O)2]nand [Cu2(BDPO)(H2O)4]nis much higherthan the alkynyl modified [Cu2(NDED)(H2O)2]nin selectivity of mixed gas. Under thesame conditions, the two acylamide groups separated from the benzene ring[Cu2(BDPT)(H2O)2]npore volume of0.571cm3/g, the amount of storage of CO2isonly53.3wt%, which is directly connected to [Cu2(BDPO)(H2O)4]npore volume of1.07cm3/g, but can be achieved98.8wt%.Therefore, in the case of containing the same coordinatively unsaturated metalsites, the insert of polarity of the acylamide group is not only to have an effectiveincrease of the pore volume of porous coordination polymer but also to effectivelyincrease the capacity of the adsorption of CO2and the selective of gas mixture. Theresearch in this paper has important theoretical significance in design and synthesisof high CO2storage capacity of porous coordination polymers modified by specialfunctional groups. At the same time, its high selectivity for gas mixtures has somepractical value in separation of gases.