Hydrothermal Synthesis, Structural Variations, and Catalytic Applications of Self-Assembled Coordination Polymers From a Novel Aminodicarboxylate Linker

Abstract

In this study, a novel aminodicarboxylic acid, 4,4′-(azanediylbis(methylene))dibenzoic acid (H₂amda), was utilized as a versatile building block to synthesize a new series of coordination polymers (CPs) via hydrothermal methods. These polymers were represented by the following formulas [Ni(Hamda)₂(μ-4,4′-bipy)(H₂O)₂]_n·2nH₂O (1), [Co(Hamda)(μ-Hamda)(μ-dpey)_0.5]_n·nH₂O (2), [Co(Hamda)(μ-Hamda)(μ-dpea)_0.5]_n·nH₂O (3), [Zn(μ-amda)(phen)]_n·0.5nH₂amda·nH₂O (4), [M(μ-amda)(2,2′-bipy)]_n (M = Co (5), Ni (6)), and [M(μ₃-amda)(μ-bpb)]_n·0.5nbpb·nH₂O (M = Co (7), Mn (8)). All synthesized compounds (1–8) were thoroughly characterized using elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction. The structural analysis revealed that compounds 1–6 exhibit one-dimensional (1D) metal–organic chains, whereas compounds 7 and 8 display two-dimensional (2D) metal–organic sheet structures. A topological classification of the underlying metal–organic networks was identified: 2C1 topology in compounds 1 and 4–6, (4,4)(0,2) topology in compounds 2 and 3, and a new topology in compounds 7 and 8. The catalytic performance of compounds 1–8 were evaluated through cyanosilylation reactions under mild conditions, optimizing diverse reaction parameters and exploring substrate scope. Among the compounds tested, compound 2 demonstrated the highest efficiency as a recyclable heterogeneous catalyst, achieving up to 98% product yield.