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The Mechanisms Of The Thermal Decompositions Of Tetrazole Derivatives:Molecular Modeling Studies

Posted on:2003-11-28Degree:DoctorType:Dissertation
Country:ChinaCandidate:J WangFull Text:PDF
GTID:1101360065460768Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
Using Ab Initio Molecular Dynamics (AIMD) method and Density Functional Theory (DFT), we report the mechanisms of thermal decompositions of four kinds of tetrazole derivatives, which are 5-NO2-1-H-tetrazole, 5-NH2-1-H-tetrazole, 5-H-1-H-tetrazole and 5-N3-1-H- tetrazole.For the ab initio molecular dynamics studies on the unimoleculars decomposition of the four tetrazole derivatives, dissociation trajectories are simulated at different temperatures using the VASP package. Based on these results, further calculations of 32 minimum points and 28 transition state structures are performed using Gaussian 98 at B3LYP/6-31G(d) level, whereas MP2/6-31G(d,p), MP4/6-31G(d,p) and CCSD(t)/6-31G(d,p) are used for the high accuracy single point calculation. The energy calculation is in good agreement with previously reported high level calculations. Also 8 minimum points and 6 transition state are optimized under HF/6-31G(d) level. The reaction channels reported in the thesis include four thermal decomposition pathways of 5-NO2-1-H-tetrazole, three thermal decomposition pathways of 5-NH2-1-H-tetrazole, six thermal decomposition pathways of 5-H-l-H-tetrazole and three thermal decomposition pathways of 5-N3-1-H-tetrazole. It is discovered that the direct ring rupture channel is the main pathway during the thermal decompositions of the four tetrazole derivatives. Following the reaction activation energies, the relative magnitudes of sensitivity appeare to be in the same order of the experimental sensitivity. This demonstratesthat there existed parallel relationships between them.
Keywords/Search Tags:molecular modelling, density functional theory( DFT ), ab initio molecular dynamics ( AIMD ), tetrazole derivatives, thermal decomposition, mechanisams
PDF Full Text Request
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