Molecular dynamics fission studies

By means of analogous approach as in the case of relationships in Fig. 1 we have studied mutual relationships between the characteristics of detonation and NMR chemical shifts of nitramines [26]. In contrast to the above-mentioned Fig. 1, the characteristics (i.e. heat of explosion or square of detonation velocity, D ) correlate with the N NMR chemical shifts, of nitro-group nitrogen atoms. Corresponding relationships for square of detonation velocity, D, are presented in Fig. 6. Here the if values correlate with the Sn values of the most reactive nitro groups [26]. Therefrom it follows that, that the primary fission of nitramine molecule is the same as that in the case of initiation by impact (see Scheme 1). Again this fact perfectly agrees with the conclusions drawn by Kohno et al. [27] fi-om the molecular dynamics study of impact and shock reactivity of nitramines. 

Photodissociation of small polyatomic molecules is an ideal field for investigating molecular dynamics at a high level of precision. The last decade has seen an explosion of many new experimental methods which permit the study of bond fission on the basis of single quantum states. Experiments with three lasers — one to prepare the parent molecule in a particular vibrational-rotational state in the electronic ground state, one to excite the molecule into the continuum, and finally a third laser to probe the products — are quite usual today. State-specific chemistry finally has become reality. The understanding of such highly resolved measurements demands theoretical descriptions which go far beyond simple models. 

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