Surrogates of 2,2′-Bipyridine Designed to Chelate Ag(I) and Create Metallotectons for Engineering Hydrogen-Bonded Crystals
journal contributionposted on 04.05.2011, 00:00 by Adam Duong, Valérie Métivaud, Thierry Maris, James D. Wuest
6-(Pyridin-2-yl)-1,3,5-triazine-2,4-diamine (1), 6-(pyrazin-2-yl)-1,3,5-triazine-2,4-diamine (2), and 6-(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine (3) incorporate two key structural features: (1) They resemble 2,2′-bipyridine and can therefore be expected to chelate suitable metals; and (2) they simultaneous incorporate diaminotriazinyl (DAT) groups, which engage in hydrogen bonding according to reliable patterns. As a result, ligands 1−3 are designed to react with metals to generate predictable structures held together by multiple coordinative interactions and hydrogen bonds. In particular, they react with salts of Ag(I) to yield cationic chelates analogous to those formed by 2,2′-bipyridine itself. As planned, DAT groups play a primary role in determining the observed structures, as demonstrated by their ability to engage in particularly favorable patterns of hydrogen bonding that require substantial deformation of the geometry of metallic coordination. An elegant hydrogen-bonded zipper, created spontaneously by combining simple ligand 3 with Ag(I), illustrates the power of qualitative approaches to crystal engineering based on a dual understanding of inorganic and organic chemistry.