A novel dinuclear double-stranded helical complexes of bis(terdentate) N<sub>4</sub>O<sub>2</sub> donor ligand with silver(I) and zinc(II) d<SUP>10</SUP> metal ions
A Sengül, Wen-Jwu Wang, Simon J. Coles
article (Uluslararası, Hakemli) | Yazar(lar): A Sengül, Wen-Jwu Wang, Simon J. Coles | Yıl: 2009 | Dergi/Kurum: POLYHEDRON | İndeks: WOS.SCI, WOS.IC | DOI: 10.1016/j.poly.2008.10.011 | Anahtar Kelimeler: Self-assembly, Supramolecular chemistry, Helical structures, Silver, Zinc, N,O-ligands — Özet: Reaction of the hexad
Reaction of the hexadentate N4O2-donor ligand 6,6'-bis(3-hydrazonobutan-2-one)-2,2'-bipyridine (L) with Ag-(I) and Zn-(II) affords a dinuclear double stranded helicate species [Ag2L2](2+) (1a) and [Zn2L2](2+) (1b), in which partitioning of the ligand into two bis-tridentate pyridyl-ketoimine chelating units allow each ligand to bridge both metal centres. X-ray crystallography, ESI-MS and UV-Vis spectrophotometric titration experiments reveal that the complex (1a) retains its solid-state structure in solution. The crystal structure of(1a) provides the first example of dinuclear silver(I) complex in which both of the metal centres can be approximated as a seven coordinate distorted mono-capped trigonal prism in which the Ag center dot center dot center dot Ag close contact of 3.034(4) angstrom is taken into account and forms the cap. The counter-ions do not interact with metal centres but hydrogen bond to N-H protons of the hydrazonic arms from the separate strands. The adjacent helical units are cross-linked together via NH center dot center dot center dot O-keto hydrogen bonding to maintain the supramolecular structure. (C) 2008 Elsevier Ltd. All rights reserved