Ligands containing the bidentate 2-pyridyl-1,2,3-triazole and tridentate 2,6-pyridyl-bis(1,2,3-triazole) moieties have emerged as alternatives to 2,2'-bypridine and 2,2':6',2''-terpyridine and other nitrogen-containing bi- and tri-dentate chelators. Because these "click" ligands are readily functionalised they are attractive options for the development of functional coordination complexes. This Frontiers Article discusses key recent reports on functional CuAAC "click" complexes in the areas of biological agency, photophysics, and catalysis.

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Self-assembled metallosupramolecular architectures (MSAs) with built-in functionalities such as light-harvesting metal centers are a promising approach for developing emergent properties within discrete molecular systems. Herein we describe the synthesis of two new but simple "click" ligands featuring a bidentate 2-pyridyl-1,2,3-triazole chelate pocket linked to a monodentate pyridyl (either 3-or 4substituted, L1 and L2) unit. The ligands and the corresponding four Pd II and Pt II metallo-ligands (Pd1, Pd2, Pt1 and Pt2) were synthesized and characterized using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and X-ray crystallography. Solid-state characterization of the series of ligands and metallo-ligands revealed that these compounds display a co-planar conformation of all the aryl units. The Pt II containing metallo-ligands (Pt1 and Pt2) were found to assemble into square (Sqr) and triangular (Tri) shaped architectures when combined with neutral PdCl 2 linker units. Additionally, the ability of the Pt II metallo-ligands and Tri to photocatalyze the cycloaddition of singlet oxygen to anthracene was investigated.[a] N.

The templated clipping of a ferrocene-grafted isophthalic acid derivative to encircle a hydrogen-bonding axle through the reaction with 1,4-bis(aminomethyl)benzene is described. The constituent electroactive macrocycle of the resultant [2]rotaxane is a homologue of the versatile benchmark tetraamide variant developed by Leigh and co-workers. The relative templating effect of different hydrogen-bonding motifs in rotaxane and pseudorotaxane generation is compared, with yields varying from 0 to 41%. The electrochemical properties and single crystal X-ray structure of a doubly ferrocene-decorated [2]rotaxane are further reported.