The HETTAP Approach: Self-Assembly and Metal Ion Sensing of Dumbbell-Shaped Molecules and Clip Molecules

The pentacoordinated terpyridine−phenanthroline zinc(II) complex motif, conceived along the HETTAP concept,
allows the preparation of a set of multicomponent supramolecular dumbbell and clip assemblies from various
bisterpyridines. All assemblies show a notable luminescence at 350−400 nm. The formation of dumbbell [Zn2(1b)2(2b)]4+ is convincingly demonstrated from the X-ray crystal structure analysis. Both dumbbell [Zn2(1b)2(2b)]4+ and
clip [Zn2(1d)(2b)]4+ allow the monitoring of Hg2+ ions due to highly selective quenching of the emission that is
driven by a Zn2+ → Hg2+ exchange process, while the more-strained clip [Zn2(1d)(2c)]4+ does not undergo such
metal exchange and does not show quenching of the luminescence. Consequently, these assemblies exhibit a
highly selective response due solely to supramolecular effects.

基于HETTAP概念设计的五配位三联吡啶-菲咯啉锌(II)配合物基元，可通过多种双三联吡啶制备一系列多组分超分子哑铃型与夹型组装体。所有组装体均在350~400 nm波长范围内表现出显著的发光性能。通过X射线晶体结构分析，确凿证实了哑铃型组装体[Zn₂(1b)₂(2b)]⁴+的形成。哑铃型组装体[Zn₂(1b)₂(2b)]⁴+与夹型组装体[Zn₂(1d)(2b)]⁴+均可通过由Zn²+→Hg²+置换过程驱动的高选择性发光猝灭，实现对Hg²+离子的检测；而空间张力更大的夹型组装体[Zn₂(1d)(2c)]⁴+无法发生此类金属置换，也未表现出发光猝灭现象。因此，这些组装体仅通过超分子效应即可实现高选择性响应。