Choi Changhyeok, Yoo Hae-Wook, Goh Eun Mee, Cho Soo Gyeong, Jung Yousung
Graduate school of Energy Environment Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Daejeon 305-701, Korea.
Agency for Defense Development , P.O Box 35-42, Yuseong, Daejeon 34186, Korea.
J Phys Chem A. 2016 Jun 23;120(24):4249-55. doi: 10.1021/acs.jpca.6b04226. Epub 2016 Jun 14.
We have studied molecular structures and kinetic stabilities of M(N5)3 (M = Sc, Y) and M(N5)4 (M = Ti, Zr, Hf) complexes theoretically. All of these compounds are found to be stable with more than a 13 kcal/mol of kinetic barrier. In particular, Ti(N5)4 showed the largest dissociation energy of 173.0 kcal/mol and thermodynamic stability. This complex had a high nitrogen content (85% by weight), and a significantly high nitrogen to metal ratio (20:1) among the neutral M(N5)n species studied here and in the literature. Ti(N5)4 is thus forecasted to be a good candidate for a nitrogen-rich high-energy density material (HEDM). We reveal in further detail using ab initio molecular dynamics simulations that the dissociation pathways of M(N5)n involve the rearrangements of the bonding configurations before dissociation.
我们从理论上研究了M(N₅)₃（M = Sc、Y）和M(N₅)₄（M = Ti、Zr、Hf）配合物的分子结构和动力学稳定性。发现所有这些化合物都很稳定，具有超过13千卡/摩尔的动力学势垒。特别是，Ti(N₅)₄表现出173.0千卡/摩尔的最大解离能和热力学稳定性。该配合物具有高氮含量（按重量计85%），并且在本文和文献中研究的中性M(N₅)ₙ物种中具有显著高的氮与金属比（20:1）。因此，Ti(N₅)₄预计是一种富含氮的高能量密度材料（HEDM）的良好候选物。我们使用从头算分子动力学模拟进一步详细揭示，M(N₅)ₙ的解离途径涉及解离前键合构型的重排。
