Mechanism of Solid-State Thermolysis of Ammonia Borane: A 15N NMR Study Using Fast Magic-Angle Spinning and Dynamic Nuclear Polarization

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• 作者：Takeshi Kobayashi ; Shalabh Gupta ; Marc A. Caporini ; Vitalij K. Pecharsky ; Marek Pruski
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 28, 2014
• 年：2014
• 卷：118
• 期：34
• 页码：19548-19555
• 全文大小：404K
• ISSN：1932-7455

文摘

The solid-state thermolysis of ammonia borane (NH₃BH₃, AB) was explored using state-of-the-art ¹⁵N solid-state NMR spectroscopy, including 2D indirectly detected ¹H{¹⁵N} heteronuclear correlation and dynamic nuclear polarization (DNP)-enhanced ¹⁵N{¹H} cross-polarization experiments as well as ¹¹B NMR. The complementary use of ¹⁵N and ¹¹B NMR experiments, supported by density functional theory calculations of the chemical shift tensors, provided insights into the dehydrogenation mechanism of AB鈥攊nsights that have not been available by ¹¹B NMR alone. Specifically, highly branched polyaminoborane derivatives were shown to form from AB via oligomerization in the 鈥渉ead-to-tail鈥?manner, which then transform directly into hexagonal boron nitride analog through the dehydrocyclization reaction, bypassing the formation of polyiminoborane.