Coordination Polymers from an Amino-Functionalized Terphenyl-Tetracarboxylate Linker: Structural Multiplicity and Catalytic Properties.

An amino-functionalized terphenyl-tetracarboxylic acid, 2'-amino-[1,1':4',1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid (Htpta), was used as an adaptable linker to synthesize, under hydrothermal conditions, eight coordination polymers (CPs). The obtained products were formulated as [Co(μ-Htpta)] (), [Co(μ-Htpta)(2,2'-bipy)] (), [M(μ-Htpta)(2,2'-bipy)] (M = Mn (), Cd ()), [Ni(μ-tpta)(phen)(HO)] (), [Zn(μ-tpta)(phen)] (), {[Zn(μ-tpta)(μ-4,4'-bipy)]·HO} (), and [Zn(μ-tpta)(μ-Hbiim)(HO)] (), wherein 2,2'-bipyridine (2,2'-bipy), 4,4'-bipyridine (4,4'-bipy), 1,10-phenanthroline (phen), or 2,2'-biimidazole (Hbiim) are present as additional stabilizing ligands. The structural types of - vary from one-dimensional (1D) (, ) and two-dimensional (2D) (, , ) CPs to three-dimensional (3D) metal-organic frameworks (MOFs) (, , and ) with a diversity of topologies. The products - were investigated as catalysts in the Knoevenagel condensation involving aldehydes and active methylene derivatives (malononitrile, ethyl cyanoacetate, or -butyl cyanoacetate), leading to high condensation product yields (up to 99%) under optimized conditions. Various reaction conditions, substrate scope, and catalyst recycling were investigated. This work broadens the application of Htpta as a versatile tetracarboxylate linker for the generation of diverse CPs/MOFs.