| Titre : | Searching for Neutralisers of Energetic Organic Compounds: A Theoretical Approach from the Perspective of Quantum Chemistry |
| Auteurs : | Nassima Bachir, Auteur ; Nadjib Melkemi, Directeur de thèse ; Samir Kenouche, Directeur de thèse |
| Type de document : | Thése doctorat |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2024 |
| Format : | 1 vol. (102p.) / ill., couv. ill. en coul / 30 cm |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Mots-clés: | Energetic molecules, neutralisers, metallocene methyl cations, sensitivity, MEP/ EDA-NOCV/ QTAIM/ IRI analysis, trigger bonds. |
| Résumé : |
Neutralising energetic molecules is a valuable approach to minimize the risks of unpredictable explosions and associated tragic events. Quantum chemical methods offer highly efficient and effective tools for studying these compounds. The main objective of this dissertation is to quantify the impact of intermolecular interactions on the sensitivity of energetic compounds. Concerning the cyclic compounds RDX (1,3,5- trinitro-1,3,5-triazinane) and HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane), a quantitative analysis with MEP evidenced anomalies arising from the marked depletion of negative charge distribution. The EDA-NOCV results reveal that the electrostatic and orbital contributions are the dominant factors driving the assembly of the M = {Ti, Zr, Hf}-based complexes. The chemical nature of the O· · ·M = {Ti, Zr, Hf} bonding has been investigated by using the QTAIM theory. Additionally, the topological properties of the N–NO2 trigger bonds were quantified before and after the O· · ·M interaction. These intermolecular interactions strengthens the trigger bonds, revealing an increased stability to decomposition. The IRI-based analysis was carried out to further investigate the electronic properties of group 4 transition metals in coordination environments. With regard to the aliphatic compound FOX-7 (1,1-diamino-2,2-nitroethylene), we examined three types of interactions: oxygen and nitrogen from a nitro group interacting with the metal atom, as well as nitrogen from an amino group interacting with the same metal atom. The local chemical reactivity of FOX-7 was elucidated through a quantitative study of MEP. Results derived from QTAIM showed that the C–NO2 bonds are influenced by the O· · ·M = {Ti, Zr, Hf} bonding. Furthermore, this interaction rules the complex formation when a nitro group interacts with MMCs. The interaction energies calculated by EDA-NOCV revealed that the (H2N)2C=C(NO2)- (O)NO· · · Cp2MCH+3 complexes are significantly more structurally stable (by about 21.8 kcal/mol) than the (O2N)2C=C(NH2)-H2N· · · Cp2MCH+3 complexes. This work is crucial to validate the proposal of using MMCs (metallocene methyl cations) as a neutraliser of energetic molecules. Keywords: Energetic molecules, neutralisers, metallocene methyl cations, sensitivity, MEP/ EDA-NOCV/ QTAIM/ IRI analysis, trigger bonds. |
| Sommaire : |
I Bibliographic study on energetic organic compounds 1 I.1 Brief history of energetic compounds . . . . . . . . . . . . . . . . . . . 8 I.2 What is an energetic compound? . . . . . . . . . . . . . . . . . . . . . 10 I.3 Classification of energetic compounds . . . . . . . . . . . . . . . . . . . 10 I.3.1 Depending on their chemical composition . . . . . . . . . . . . . 10 I.3.1.1 Pure single energetic compounds . . . . . . . . . . . . 10 I.3.1.2 Energetic mixtures . . . . . . . . . . . . . . . . . . . . 13 I.3.2 Depending on their intended use . . . . . . . . . . . . . . . . . . 14 I.3.2.1 Explosives . . . . . . . . . . . . . . . . . . . . . . . . . 14 I.3.2.2 Propellants . . . . . . . . . . . . . . . . . . . . . . . . 15 I.3.2.3 Pyrotechnics . . . . . . . . . . . . . . . . . . . . . . . 15 I.4 Decomposition of energetic compounds . . . . . . . . . . . . . . . . . . 16 I.4.1 Decomposition regimes . . . . . . . . . . . . . . . . . . . . . . . 16 I.4.1.1 Detonation . . . . . . . . . . . . . . . . . . . . . . . . 17 I.4.1.2 Deflagration . . . . . . . . . . . . . . . . . . . . . . . . 17 I.4.1.3 Combustion . . . . . . . . . . . . . . . . . . . . . . . . 17 I.5 Civil applications of energetic compounds . . . . . . . . . . . . . . . . . 17 I.6 Sensitivity of energetic compounds . . . . . . . . . . . . . . . . . . . . 18 I.7 Factors affecting the sensitivity of energetic compounds . . . . . . . . . 19 I.7.1 Molecular indices related with sensitivity . . . . . . . . . . . . . 19 I.8 Reducing sensitivity: a major challenge . . . . . . . . . . . . . . . . . 20 I.9 Efforts towards sensitivity reduction . . . . . . . . . . . . . . . . . . . . 21 I.10 Safety of energetic compounds: . . . . . . . . . . . . . . . . . . . . . . 23 I.11 Some of history’s serious accidents caused by energetic compounds . . . 24 I.12 Trigger linkage concept . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 I.13 Neutralisation of energetic compounds by using MMCs . . . . . . . . . 26 II Quantum chemical methods 28 II.1 The Schr¨odinger equation . . . . . . . . . . . . . . . . . . . . . . . . . 39 II.2 Hartree-Fock theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 II.2.1 The Hartree-Fock equations . . . . . . . . . . . . . . . . . . . . 42 II.3 Post Hartree-Fock methods . . . . . . . . . . . . . . . . . . . . . . . . 45 II.4 Density Functional Theory (DFT) . . . . . . . . . . . . . . . . . . . . . 45 II.4.1 Kohn-Sham equations . . . . . . . . . . . . . . . . . . . . . . . 46 II.4.2 The main exchange-correlation density functionals of DFT . . . 48 II.4.2.1 Local Density Approximation . . . . . . . . . . . . . . 48 II.4.2.2 Generalized Gradient Approximation (GGA) and Hybrid Functionals . . . . . . . . . . . . . . . . . . . . . 48 II.5 Molecular Electrostatic Potential (MEP) . . . . . . . . . . . . . . . . . 49 II.6 Energy Decomposition Analysis-Natural Orbitals for Chemical Valence (EDA-NOCV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 II.7 Quantum Theory of Atoms In Molecules (QTAIM) . . . . . . . . . . . 51 II.8 Interaction Region Indicator (IRI) . . . . . . . . . . . . . . . . . . . . . 53 III Theoretical Investigation of the Effect of O · · ·M = {Ti,Zr,Hf} Interactions on the Sensitivity of RDX and HMX 54 III.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 III.2 Computational details . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 III.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 III.3.1 MEP analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 III.3.2 EDA-NOCV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 III.3.3 QTAIM analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 67 III.3.4 IRI analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 III.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 IV The effect of {O,N} = X· · ·M = {Ti, Zr, Hf} interactions on the sensitivity of C-NO2 trigger bonds in FOX-7. 81 IV.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 IV.2 Computational details . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 IV.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 IV.3.1 Electrostatic potential analysis . . . . . . . . . . . . . . . . . . 89 IV.3.2 Topological analysis of electron density . . . . . . . . . . . . . . 91 IV.3.3 Bond length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 IV.3.4 EDA-NOCV analysis . . . . . . . . . . . . . . . . . . . . . . . . 98 IV.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 |
| Type de document : | Thése doctorat |
| En ligne : | http://thesis.univ-biskra.dz/id/eprint/6404 |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| TCH/110 | Théses de doctorat | bibliothèque sciences exactes | Consultable |
