Progress in design and applications of supramolecular assembly of 2,2′:6′,2″-terpyridine-based first row d-block elements

2,2′:6′,2″-Terpyridine (tpy)-based transition metal complexes have continued to receive attention due to their outstanding features and promising industrial and biomedical applications. Recently, knowledge of the supramolecular chemistry of this class of complexes has expanded to their physicochemical behavior, such as luminescence, their responsiveness to external stimuli such as advanced functional materials, and biological activities, as well as their prospective applications, including catalysis. This review is focused on the design of mono(terpyridine) or bis(terpyridine)-based first-row 3d elements that range from supramolecular architectures to coordination polymers. The majority of these complexes are based on late transition metals and zinc, followed by middle transition metals, while there have been few examples of early transition metals reported to date. The design of heterobimetallic 3d/4f or 5f has also been particularly interesting in preparing supramolecular networks of late transition metals. The design of terpyridine-based metalloligands, such as ferrocene core functionalized terpyridine, has provided simple approaches to preparing heterometallic supramolecular architectures. This review illustrates the introduction of a second ligand, particularly ligands having carboxylate or nitrogen donor atoms, in the preparation of metal coordination polymers or supramolecular networks. The up-to-date information on the synthetic approaches to these materials, as well as their structures, properties, and applications, has been emphasized. It is important to note that although various characterization techniques of spectroscopy have been utilized to elucidate the structural features of these networks, X-ray crystal structure analysis has been employed to provide detailed structural information about intermolecular interactions, including hydrogen bonding and π···π stacking interactions, which influence the overall stability and properties of the networks such as luminescence properties and multistimuli responses. The self-assembly in these classes of compounds plays an important role in the design of novel functional materials, nanostructures, and biomaterials.