Tailoring dynamic hydrogels by controlling associative exchange rates
Tailoring dynamic hydrogels by controlling associative exchange rates
复制标题
通过控制缔合汇率定制动态水凝胶
DOI：
10.1016/j.chempr.2023.05.018
复制
发表时间：
2023
期刊：
影响因子：
23.5
通讯作者：
Kalow, Julia A.
中科院分区：
文献类型：
--
作者：
Zhang, Vivian;Accardo, Joseph V.;Kevlishvili, Ilia;Woods, Eliot F.;Chapman, Steven J.;Eckdahl, Christopher T.;Stern, Charlotte L.;Kulik, Heather J.;Kalow, Julia A.
二硫代亚烷基是一类新开发的共轭受体，通过缔合机制进行硫醇交换，使关键材料特性的可持续性，生物医学和传感应用去耦。在这里，我们表明，交换率是高度敏感的受体的结构和可调超过四个数量级的水环境中。环状受体的交换速度很快，从0.95到15.6 M−1s−1，而非环状受体的交换速度在3.77 × 10− 3到2.17 × 10−2M−1s−1之间。计算，光谱和结构数据表明，环状受体比它们的非环状对应物更活泼，因为四面体交换中间体的共振稳定。我们parametrize分子反应性相对于计算的亲电位点的描述符，并利用这种洞察力来设计一个化合物的中间特性。最后，我们将这种动态键结合到水凝胶中，并证明特征应力松弛时间（τ）与分子量成正比。
Dithioalkylidenes are a newly developed class of conjugate acceptors that undergo thiol exchange via an associative mechanism, enabling decoupling of key material properties for sustainability, biomedical, and sensing applications. Here, we show that the exchange rate is highly sensitive to the structure of the acceptor and tunable over four orders of magnitude in aqueous environments. Cyclic acceptors exchange rapidly, from 0.95 to 15.6 M−1s−1, whereas acyclic acceptors exchange between 3.77 × 10−3and 2.17 × 10−2M−1s−1. Computational, spectroscopic, and structural data suggest that cyclic acceptors are more reactive than their acyclic counterparts because of resonance stabilization of the tetrahedral exchange intermediate. We parametrize molecular reactivity with respect to computed descriptors of the electrophilic site and leverage this insight to design a compound with intermediate characteristics. Lastly, we incorporate this dynamic bond into hydrogels and demonstrate that the characteristic stress relaxation time (τ) is directly proportional to molecularkex.