Synthesis, Structure, and Heterogeneous Catalysis of a Series of Structurally Diverse Coordination Polymers Based on 5-Nitroisophthalate
Subham Sahoo, Debajit Sarma
Abstract
Four new coordination polymers have been synthesized based on a mixed-ligand strategy, viz., [Cu(4-ABPT)(HNIPA)2H2O]·H2O, SSICG-1; [Cu2(4-ABPT)2(HNIPA)4]·H2O, SSICG-2; [Ni(4-ABPT)(NIPA)H2O], SSICG-3; and [Zn2(ATRZ)2(NIPA)], SSICG-4 (4-ABPT = 3,5-di(pyridine-4-yl)-4H-1,2,4-triazol-4-amine, H2NIPA = 5-nitroisophthalic acid, and ATRZ = 3-amino-1,2,4-triazole, SSICG stands for the Solid State and Inorganic Chemistry Group at IIT Patna). The copper compounds are one-dimensional, whereas the nickel and zinc compounds are two-dimensional layer compounds. SSICG-3 possesses 4,4-net topology with a Schläfli symbol 44.62, whereas SSICG-4 exhibits a 3,3-net (fes) topology with a Schläfli symbol 4.82. SSICG-1 and SSICG-3 have active metal sites due to the presence of replaceable coordinated water molecules and exhibits efficient catalytic activity for one-pot CO2 cycloadditions. The conversions of SSICG-1 and SSICG-3 for CO2 cycloaddition are 87 and 95% (turnover numbers (TON) of 174 and 190), respectively. The kinetic studies, substrate scope, recyclability, catalyst amount, and temperature dependence studies of the CO2 cycloaddition reaction are discussed. These structurally diverse coordination polymers could contribute to broadening the scope of mixed-ligand coordination polymers for their applications in heterogeneous catalysis.