Hexagon Wreaths: Self-Assembly of Discrete Supramolecular Fractal Architectures Using Multitopic Terpyridine Ligands

• DOI: 10.1021/ja501417g
• Publication Date: 2014-04-14T20:17:08Z
• Authors: Ming Wang; Chao Wang; Xin-Qi Hao; Jingjing Liu; Xiaohong Li; Chenglong Xu; Alberto Lopez; Luyi Sun; Mao-Ping Song; Hai-Bo Yang; Xiaopeng Li
• Keywords: Terpyridine

In this study, we overcame a challenge in conventional self-assembly of macrocycles that uses ditopic 2,2':6',2″-terpyridine (tpy) building blocks with 120° angle between two ligating moieties, which generally produces mixture multiple instead single hexagon. Two supramolecular hexagon wreaths, [Zn9LA6] and [Zn12LB6], were designed self-assembled from tritopic tetratopic tpy ligands Zn(II) ions, respectively. These multitopic ligands, bearing binding sites, increased the total density coordination sites provided high geometric constraints to induce formation discrete structures. Such constructed by simple recursion small hexagons around central hexagon, exhibit fractal geometry features self-similarity at different levels. The shapes, sizes, structures fully characterized NMR, ESI-MS, traveling-wave ion mobility mass spectrometry (TWIM-MS), transmission electron microscopy. With diameters 5.5 nm for 5.8 remarkable rigidity these architectures was supported TWIM-MS, contrast flexibility assembled ligands.