Pressure-induced complexation of NH3BH3-H2
Pressure-induced complexation of NH3BH3-H2
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DOI：
10.1063/1.3174262
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发表时间：
2009-12-14
影响因子：
4.4
通讯作者：
Hemley, Russell J.
中科院分区：
文献类型：
--
作者：
Chellappa, Raja S.;Somayazulu, Maddury;Hemley, Russell J.
高压拉曼光谱的NH 3BH 3-H-2混合物高达60 GPa揭示了不寻常的压力诱导络合和分子间的相互作用。复合物中H-2的拉伸模式出现在6.7和10 GPa下，随着压力的增加频率增加到60 GPa，具有不同的压力系数，并且在类似于40 GPa下，较低的频率模式接近体H-2的振动子频率。压力诱导的纯NH3 BH 3研究高达60 GPa的转变揭示了在1 GPa（第二阶段）和进一步的转变在5（第三阶段）和10 GPa（第四阶段）的无序有序过渡。纯NH_3BH_3和NH_3BH_3-H-2复合物的光谱都提供了N-H δ +中心点H δ-B氢键键在50 GPa以下加强的证据，超过50 GPa它们减弱。在NH3 BH 3-H-2复合物中，由于在15和20 GPa之间与H-2的相互作用，氢键断裂。NH3 BH 3-H-2复合物中的nu（NH3）模式的行为表明NH3官能团在所观察到的相互作用中起主导作用。
High pressure Raman spectroscopy of NH3BH3-H-2 mixtures up to 60 GPa reveals unusual pressure-induced complexation and intermolecular interactions. Stretching modes of H-2 in the complex arise at 6.7 and 10 GPa, increasing in frequency with pressure of up to 60 GPa with different pressure coefficients, and at similar to 40 GPa, the lower frequency mode approaches vibron frequency of bulk H-2. Pressure-induced transformations in pure NH3BH3 studied up to 60 GPa reveal a disorder-order transition at 1 GPa (phase II) and further transitions at 5 (phase III) and 10 GPa (phase IV). The spectra of both pure NH3BH3 and the NH3BH3-H-2 complex provide evidence for strengthened of the N-H delta+center dot H delta--B dihydrogen bonding linkages up to 50 GPa, beyond which they weaken. The dihydrogen bonding breaks down due to interactions with H-2 between 15 and 20 GPa in the NH3BH3-H-2 complex. The behavior of the nu(NH3) modes in the NH3BH3-H-2 complex indicates a dominant role of the NH3 functional group in the observed interactions.