Multiresponsive supramolecular gels constructed by orthogonal metal–ligand coordination and hydrogen bonding

Self‐Healing Metallo‐Supramolecular Hydrogel Based on Specific Ni2+ Coordination Interactions of Poly(ethylene glycol) with Bistriazole Pyridine Ligands in the Main Chain

“…The selective gelation induced by Ni 2+ can be explained by the higher overall association constant β of the complexes in water, which has been reported to be in the order Ni 2+ > Fe 2+ > Zn 2+ > Cu 2+ , if we consider that metal complexation with btp is analogous to terpyrdine . Moreover, the high chain length of the PEG could also interfere with the hydrogel formation by interacting with the metal ions, which is consistent with the recent work of Weng et al on btp based organogels …”

The btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] binding motif: a new versatile terdentate ligand for supramolecular and coordination chemistry

“…More recently, Weng and co-workers have also reported self-healing btp systems with stress-sensing abilities, 163 and PEG-linked systems, which formed multiresponsive gels both in the presence and absence of Eu(III). 164 We reported [Ru(4b) 2 ](PF 6 )Cl, the first example of a metal complex gelator derived from discrete mono-btp components, the X-ray crystal structure of which suggests that it is able to induce solvent gelation by the formation of supramolecular polymer chains through hydrogen bond interactions between the carboxylic groups, ethanol solvent molecules and chloride anions. A viscous yellow soft material was formed which, when immobilised on a quartz slide, exhibited ligand-centred emission much like that seen for the complex in solution.…”

Recent progress in luminescent self-healing gels

“…有趣的是, 形成凝胶之 后荧光强度显著增强, 其原因在于荧光物质在凝胶 的聚集态中, 其非辐射衰减减少. 在金属离子中, 镧 系元素 [57] 由于具有较高的配位常数, 优异的发光性 图 5 (a) 不同离散凝胶组建的 1D 多重荧光材料的荧光发 射光谱(λ ex =330 nm), 插入的是 1D 材料的卡通图; (b~g) 多 重荧光材料示意图: (b, e) 2D、3D 卡通示意图; (c, f) 在日光 照射下的图片; (d, g) 在 365 nm 紫外灯下的图片(比例尺: 1 cm) [61] Gunnlaugsson 等 [64] 运用 Btp 配体为基体合成了 5 图 7 (a) Upy 基团自组装形成二聚体及加入金属形成配位 作用的示意图; (b) 无金属存在时的大分子溶液; (c) 加入金 属 Eu 后形成凝胶且显示其特征光谱 [62] ; (d) 在 Y 和 Z 位置 不同功能基团的 Btp 配体结构 [64] 光作为一种方便有效的外界刺激, 因其具有时 间和空间的远程可控性、可精确控制的优点, 常被用 来设计光敏性智能材料 [81] . 在上述报道的发光自愈 合凝胶中, 尚未涉及凝胶的发光刺激响应性.…”