The azide complex [Na(15-crown-5)](2)[L(N-3)(2)] has been synthesized. X-ray single-crystal diffraction analysis revealed that two orthogonally oriented aside anions are encapsulated in one receptor, each by two opposite urea edges of the square tetreurea ligand through N-(urea) - H center dot center dot center dot N-(azide) hydrogen bonding. UV-vis titration confirmed the 1:2 (host/guest) binding mode in solution with slight bathochromic shifts compared to the ligand. (C) 2011 Elsevier B.V. All rights reserved.
Chloride Coordination by Oligoureas: From Mononuclear Crescents to Dinuclear Foldamers
作者:Biao Wu、Chuandong Jia、Xiaolei Wang、Shaoguang Li、Xiaojuan Huang、Xiao-Juan Yang
DOI:10.1021/ol2031153
日期:2012.2.3
A series of acyclic oligourea receptors which closely resemble the scaffolds and coordination behavior of oligopyridines have been synthesized. Assembly of the receptors with chloride ions afforded mononuclear anion complexes or dinuclearfoldamers depending on the number of the urea groups.