Purine Compounds Are Studied As High Energy Density Materials

High Energy Density Materials (HEDMs) refers to the Compoundsby High Energy Density and a variety of other ingredients (such asadhesives, plasticizer and pure feeling agent, etc.). High energydensity materials in the military, the application of fuel andfireworks is very extensive. However, in the lab synthetic HEDCsand developed the excellent performance of HEDM formula requiresa lot of manpower, material and financial resources, and the longexperiment cycle. Moreover, explosives have its owncharacteristics of oxidation and decomposition, so the synthesisand formulation experiment contains certain risk. This paper adoptsthe quantum chemistry calculation method of DFT (Densityfunctional theory) to the study of the theory of the purinederivatives are discussed in detail. Material is obtained by using thekey reactions such as the generation of heat, combined withKamlet-Jacobs equation calculation molecular detonationperformance. The thermal stabilites of the title compounds wereevaluated by calculating BDE of the trigger bond, which is judgedaccording to the principle of the smallest bond order and Mullikenpopulation analyses. Using the calculated detonation performanceand the stability of molecules, elect performance superior high energy density materials. In this paper, the three type purinecompounds have been studied in detail using quantum chemicalcalculation method. These results may provide laboratory synthesisof a large number of theoretical basis.1. Nitropurine derivativesTo look for high energy density materials (HEDMs), a series ofpurine derivatives with nitro groups have been designedcomputationally. The relationships between the structures and theperformances of polynitropurines were studied. Density functionaltheory (DFT) B3LYP/6-311G**was employed to evaluate the heats offormation (HOFs) for polynitropurines by designing isodesmicreaction method. Results indicated the values of HOFs wereinfluenced by the number and position of substituent groups. Therelative stabilities of polynitropuines were studied by the pyrolysismechanism using the UB3LYP/6-311G**method. The homolysis ofthe ring-NO2bond is predicted to be the initial step of thermaldecomposition. Taking detonation properties and relative stabilityinto account, tetranitropurines derivative may be regarded as thepotential candidates of practical HEDCs.2. Nitraminepurines derivativesA series of purine derivatives with nitramine groups werecalculated by using density functional theory (DFT). The moleculartheory density, heats of formation, bond dissociation energies anddetonation performance are investigated at DFT-B3LYP/6-311G**level. The isodesmic reaction method was employed to calculatethe HOFs of the energies obtained from electronic structurecalculations. Results show that the position of nitramine groups can influence the values of HOFs. The bond dissociation energiesand bond orders of the weakest bonds were analyzed to investigatethe thermal stability of the purine derivatives. The calculated bonddissociation energies of Ring-NHNO2and NH-NO2bond show thatthe NH-NO2bond should be the trigger bond in pyrolysis processes.Considered the detonation performance and thermal stability, twoderivatives may be regarded as potential novel high energy densitycompounds (HEDCs).3. Difluoroaminopurine derivativesDensity functional theory (DFT) was used to study the heats offormation (HOFs), electronic structure, energetic properties andthermal stability for a series of purine derivatives withdifluoroamino groups. The isodesmic reaction method wasemployed to calculate the HOFs of the energies obtained fromelectronic structure calculations. Results indicated the position ofdifluoroamino groups can influence the values of HOFs. The bonddissociation energies and bond orders of the weakest bonds wereanalyzed to investigate the thermal stability of the purinederivatives. Furthermore, the detonation velocities and pressurewere evaluated by using the Kamlet-Jacobs equations. Thecylinder wall velocities (V) were also calculated using thesimplified calculational method. Compared with the conventionalexplosives, two purine derivatives may be regarded as the potential candidates of practical HEDCs.