A simple and environmentally benign synthesis of polypyridine-polycarboxylic acids

Photochemical, Electrochemical, and Photoelectrochemical Water Oxidation Catalyzed by Water‐Soluble Mononuclear Ruthenium Complexes

“…The ligand H 4 tcbp was synthesized by a simple two‐step reaction 45. First, 4,4′,6,6′‐tetramethyl‐2,2′‐bipyridine (tmbp) was obtained by coupling commercially available 2,4‐dimethylpyridine, which was further oxidized using dilute nitric acid solutions under solvothermal conditions.…”

“…The ligand H 4 tcbp was synthesized by a simple two-step reaction. [45] First, 4,4',6,6'-tetramethyl-2,2'-bipyridine (tmbp) was obtained by coupling commercially available 2,4-dimethylpyridine, which was further oxidized using dilute nitric acid solutions under solvothermal conditions. Complexes 1 and 2 were prepared by a similar procedure, wherein H 4 tcbp, [RuCl 2 (dmso) 4 ] and triethylamine were refluxed in methanol overnight under a nitrogen atmosphere, followed by the addition of excess free axial ligands (isoquinoline for 1 and 4-picoline for 2).…”

Crystal Engineering of 6-Carboxy-4-aryl-2,2′-bipyridine Complexes: Potent Chelators with Intrinsic Intermolecular Affinity

“…In the ongoing drive toward new functional supramolecular systems, a constant need exists for the discovery and development of new ligand systems, binding motifs, and molecular scaffolds, in order to diversify the existing chemical toolbox and rationally pursue specific applications. − To this end, significant progress has been made recently in establishing modular ligand sets for further development into supramolecular systems. , Doing so requires a thorough basis in the fundamental coordination chemistry and structural trends of archetypal systems, to establish the necessary understanding of the subtle geometric and electronic effects which are well-known to strongly influence the bulk properties of such systems. − The polypyridine family of ligands are well-known metallosupramolecular ligand scaffolds, widely exploited in transition metal coordination chemistry, due to the predictable coordination behavior and favorable electronic and magnetic properties of bipyridine and terpyridine d-metal ion complexes. , These structures have found myriad applications, including as dye-sensitized solar cells, redox photocatalysts, molecular electronics, and spin crossover devices. − As well-established starting points, functional 2,2′-bipyridine derivatives are ideally suited for the installation of new substitution patterns and functional groups . Although direct derivatization of the deactivated pyridine ring itself can be synthetically cumbersome compared to other nitrogen heterocycles, new synthetic methods are continually emerging for the synthesis of functional bipyridine ligands. , …”

“…17 Although direct derivatization of the deactivated pyridine ring itself can be synthetically cumbersome compared to other nitrogen heterocycles, 18 new synthetic methods are continually emerging for the synthesis of functional bipyridine ligands. 19,20 The scope of possible modification to the 2,2′-bipyridine backbone includes the incorporation of additional chelating groups at the 6 and/or 6′ positions, with the view of increasing the metal binding affinity, while functionalization at the 4 and/or 4′ positions allows for the grafting of additional chemical functionality, or structural handles, for engineering ions with bridging through additional carboxylate functionality. 24 In that case, the unsymmetric substitution of the bipyridine skeleton was achieved by partial decarboxylation of the tetracarboxylic acid precursor.…”

A more efficient synthesis of 4,4′,4′′-tricarboxy-2,2′:6′,2′′-terpyridine

“…In addition, owing to recent literature, it should be possible to further improve the synthesis of 1, for example by modifying the oxidation of the alkyl chains. 34,35 This journal is © The Royal Society of Chemistry 2011 Green Chem., 2011, 13, 3337-3340 | 3339…”