Multifunctional Porous Coordination Polymers Synthesized by the Variation of Chain Length and Flexibility of Dicarboxylates and Size of the Metal Ions

Abstract

Intriguing properties exhibited by porous coordination polymers (PCPs) have been discussed for a very long time, and the peak of the journey has been reached. Many ways have been introduced side by side to explore in the domain of PCPs with further progress to achieve various functionalities. Multifunctionality by these types of frameworks is one of those interesting features which has also been challenged to produce proper frameworks for exhibiting multiple properties by a single structure. Thus, after judicial choice of two different types of ligands, three coordination polymers {[Cd(1,4-(2-Me)-bix)(glu)]·5(H2O)}n (1), {[Cd2(1,4-(2-Me)-bix)(msuc)]·(H2O)}n (3), and {[Zn(1,4-(2-Me)-bix)(msuc)]·(solvent)x}n (4) have been synthesized and characterized. These three compounds along with one previously reported structurally similar complex {[Zn(1,4-(2-Me)-bix)(glu)]·4(H2O)}n (2) have been used to study gas sorption, electrical properties in dark and light, and luminescence. All the PCPs display different gas adsorptions (CO2, N2, H2) and electrical conductance in both dark and illuminated conditions, which is an indication of multifunctionality shown by these structures. This designed structure and the measured properties of the synthesized complexes have been correlated with each individual framework of the four complexes based on the dicarboxylate flexibility/substitution and the size of the metal ion.