An Ab Initio Study of Potential Energy Surfaces for N 8 Isomers

Content Provider	Semantic Scholar
Author	Chung, Gyusung Schmidt, Michael W. Gordon, Mark S.
Copyright Year	2017
Abstract	The potential energy surfaces and the nature of transition structures for the decomposition of three N8 isomers (octaazapentalene, azidopentazole, and diazidodiimide) into 4 N2 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. Disciplines Chemistry Comments Reprinted (adapted) with permission from Journal of Physical Chemistry A 104 (2000): 5647, doi:10.1021/ jp0004361. Copyright 2000 American Chemical Society. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/chem_pubs/405 An Ab Initio Study of Potential Energy Surfaces for N8 Isomers Gyusung Chung,† Michael W. Schmidt, and Mark S. Gordon* Department of Chemistry, Iowa State Uni Versity, Ames, Iowa 50011 Recei Ved: February 3, 2000; In Final Form: April 3, 2000 The potential energy surfaces and the nature of transition structures for the decomposition of three N 8 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.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1389&context=chem_pubs&httpsredir=1&referer=
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article