Observation of the transition state for pressure-induced BO3 → BO4 conversion in glass
Observation of the transition state for pressure-induced BO3 → BO4 conversion in glass
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DOI：
10.1126/science.1256224
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发表时间：
2014-08-29
期刊：
影响因子：
56.9
通讯作者：
Sen, Sabyasachi
中科院分区：
文献类型：
--
作者：
Edwards, Trenton;Endo, Takatsugu;Sen, Sabyasachi
从根本上理解压力和/或温度引起的硼配位环境的易变性对于改变玻璃的物理性质是很重要的。我们利用原位高压(高达2千兆帕斯卡)Bon-11固体核磁共振波谱，结合从头计算，研究了室温下压力诱导的BO_3~->；BO4转变的过渡态的性质。结果表明，在各向同性应力作用下，BO_3平面三角形发生各向异性弹性变形，形成三方金字塔，这可能是后续形成BO4四面体的先兆。
A fundamental mechanistic understanding of the pressure- and/or temperature-induced facile transformation of the coordination environment of boron is important for changing the physical properties of glass. We have used in situ high-pressure (up to 2 gigapascals) boron-11 solid-state nuclear magnetic resonance spectroscopy in combination with ab initio calculations to investigate the nature of the transition state for the pressure-induced BO3 -> BO4 conversion in a borosilicate glass at ambient temperature. The results indicate an anisotropic elastic deformation of the BO3 planar triangle, under isotropic stress, into a trigonal pyramid that likely serves as a precursor for the subsequent formation of a BO4 tetrahedron.