An ab initio study of potential energy surfaces for N8 isomers

被引:197
作者
Chung, GS [1 ]
Schmidt, MW [1 ]
Gordon, MS [1 ]
机构
[1] Iowa State Univ, Dept Chem, Ames, IA 50011 USA
关键词
D O I
10.1021/jp0004361
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The potential energy surfaces and the nature of transition structures for the decomposition of three Ns isomers (octaazapentalene, azidopentazole, and diazidodiimide) into 4 N-2 are investigated using ab initio methods. These isomers are all high-energy species, relative to molecular nitrogen, but are much lower in energy than the previously studied cubic structure. Second-order perturbation theory (MP2) predicts that the dissociation of octaazapentalene proceeds via isomerization to a linear molecule. The dissociation reaction of azidopentazole prefers ring breaking, at a cost of less than 20 kcal/mol, to breaking a bond in the side chain. The cis isomer of diazidodiimide is found to be slightly more stable than that of the trans isomer at the highest levels of theory used here. The coupled cluster (CCSD(T)) diazidodiimide dissociation barrier is computed to be about 20 kcal/mol. This barrier is only marginally sufficient to make this high energy density molecule metastable.
引用
收藏
页码:5647 / 5650
页数:4
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