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dc.contributor.advisorBhattacharya, Atanu
dc.contributor.authorGhosh, Jayanta
dc.date.accessioned2024-10-22T07:01:46Z
dc.date.available2024-10-22T07:01:46Z
dc.date.submitted2019
dc.identifier.urihttps://etd.iisc.ac.in/handle/2005/6652
dc.description.abstractThe thesis has been presented in two parts. In first part of the thesis, ultrafast relaxation dynamics of UV excitation induced chemistry via electronically excited states has been discussed. Taking one example from each functional group (nitro groups, such as -CNO2, -NNO2, and -ONO2), -N3 (azide group), -N=N- (diazo group), -N(O)=N- (azoxy group)) the nature of ultrafast relaxation dynamics of energetic molecules is discussed in separate chapter. The content of the thesis is presented in the following way. In chapter 2, detail theoretical background of ab initio multiple spawning (AIMS) has been presented. In chapter 3, comparison of ultrafast relaxation dynamics and mechanism of nitro-containing molecules, nitromethane (containing C–NO2 active moiety), dimethylnitramine (containing N–NO2 active moiety), and methyl nitrate (containing O–NO2 active moiety) from electronically excited state (S1) has been discussed using ab initio multiple spawning (AIMS) dynamics simulations. Comparison of relaxation dynamics of 1,2,4,5-tetrazine and 1,2,4,5-tetrazine-2,4-di-N-oxide has also been discussed. In chapter 4, ultrafast electronically nonadiabatic chemistry of methyl azide (CH3N3)8 as a model system of azide-based energetic plasticizer bis(1,3-diazido prop-2-yl)malonate has been explored by using AIMS simulation. In chapter 5, a comparison of two different internal conversion dynamics of azo and azoxy energetic moieties through the (S1/S0)CI conical intersection has been presented. In chapter 6, we have explored the role of dissociative (π,σ*) states of furazan and triazole energetic molecules in the ring opening mechanism. The second part of my thesis focuses on strong field ionization induced chemistry of energetic molecules. In chapter 7, As a generic consequence of the interaction of a strong laser field with molecules, high harmonic generation from the energetic molecule, nitromethane (CH3NO2) has been discussed. Observing HHG from energetic molecules has ultimately opened two new directions in the field of laser ignition chemistry. Experimentally observed HHG spectra have been compared with the theoretical simulated spectra using molecular electrostatic potential. In chapter 8, another direction which has opened as an initial step of strong field ionization of energetic molecules is attosecond charge migration between fuel oxidizer has been discussed. In this chapter attosecond chemical bonding and its consequences in the initial step of laser ignition chemistry has been discussed for ethylene-O2, benzene-O2, methanol-O2 van der Waals complexes. Finally, in chapter 9, general conclusions, unfinished works, and future directions has been presented.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseries;ET00662
dc.rightsI grant Indian Institute of Science the right to archive and to make available my thesis or dissertation in whole or in part in all forms of media, now hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertationen_US
dc.subjectultrafast relaxation dynamicsen_US
dc.subjectnitro-containing moleculesen_US
dc.subjectab initio multiple spawningen_US
dc.subjectenergetic moleculesen_US
dc.subjectstrong field ionization induced chemistryen_US
dc.subjecthigh harmonic generationen_US
dc.subjectattosecond chemical bondingen_US
dc.subject.classificationResearch Subject Categories::NATURAL SCIENCES::Chemistry::Physical chemistryen_US
dc.titleUltrafast Processes in Energetic Moleculesen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.grantorIndian Institute of Scienceen_US
dc.degree.disciplineFaculty of Scienceen_US


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