Direct Observation of Intermediates in a Thermodynamically Controlled Solid-State Dynamic Covalent Reaction
Direct Observation of Intermediates in a Thermodynamically Controlled Solid-State Dynamic Covalent Reaction
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DOI：
10.1021/ja500707z
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发表时间：
2014-11-19
影响因子：
15
通讯作者：
Sanders, Jeremy K. M.
中科院分区：
文献类型：
--
作者：
Belenguer, Ana M.;Lampronti, Giulio I.;Sanders, Jeremy K. M.
我们提出了第一个多晶型物相互转化的研究，使用固态动态共价化学（DCC）。该系统表现出意想不到的和丰富的行为，包括观察到，在适当的条件下，异二聚体的多晶型物相互转化通过可逆的共价化学中间体进行，并且该途径是由参与反应的两个二硫化物同二聚体之一促进的。此外，我们通过实验证明，在所有情况下都达到了动态平衡，这意味着改变研磨条件会影响两种多晶型物之间的自由能差，从而影响它们的相对稳定性。我们认为，这种效果是由于表面溶剂化能结合高的表面体积比的纳米晶粉末。
We present the first polymorph interconversion study that uses solid-state dynamic covalent chemistry (DCC). This system exhibits unexpected and rich behavior, including the observation that under appropriate conditions the polymorph interconversion of a heterodimer proceeds through reversible covalent chemistry intermediates, and this route is facilitated by one of the two disulfide homodimers involved in the reaction. Furthermore, we demonstrate experimentally that in all cases a dynamic equilibrium is reached, meaning that changing the milling conditions affects the free energy difference between the two polymorphs and thus their relative stability. We suggest that this effect is due to the surface solvation energy combined with the high surface to volume ratio of the nanocrystalline powder.