Synthesis of microporous polymer networks and Control of their electronic structure

Abstract

In this study, new microporous nanostructures so called “Acetylene mediated Conjugated Microporous Polymers (ACMPs)” have been synthesized using acetylene gas as a building unit with functional linkers via the coupling reaction, where the acetylene gas was used as a source of the functional building unit for the first time. Three types of ACMPs have been synthesized in this work. ACMP-C was fabricated by linking Tetrakis(4-iodophenyl)methane with an acetylene gas, whereas ACMP-C6 and ACMP-N were synthesized from 1,3,5-Tris(4-iodophenyl)benzene and Tris(4-iodophenyl)amine, respectively. ACMP-C is giving the highest BET surface area attributed to the tetrahedrally oriented iodine terminals suitable for formation of microporous networks. Meanwhile, ACMP-C6 was synthesized using a planar-type starting building unit with three iodine terminals less suitable for a formation of 3 dimensional networks. The starting building unit of ACMP-N is on the incomplete tetrahedron-type unit along with one lone pair electron, thus leading to a sparse network structure. Also, the structures with the triple-bond linkages have been confirmed by the solid-state 13C CPMAS NMR, consistent with those obtained from FT-IR measurements. In addition, it was identified that the significant CO2 uptake capacity of ACMP-N at 195 K are available due to the micropore network accessible by CO2 with the small kinetic diameter, although the micropore network for ACMP-N was very difficult to be accessed by the N2 molecules with the relatively large kinetic diameter. Meanwhile, as the temperature increases, we found that ACMP-C shows the highest CO2 adsorption capacity among ACMPs with 68.8 mg/g at 273 K and 47.5 mg/g at 298 K. This demonstrates that the increased kinetic diameter of CO2 at high temperatures prevents penetrating into the pores of ACMP-N, although it has lone pair electrons on nitrogen atom for a good interaction site with CO2. ACMP-C shows the smaller CO2 capacity by 3 times than 1,4...