Theoretical studies on new potential high energy density compounds (HEDCs) adamantyl nitrates from gas to solid

Abstract

A series of adamantyl nitrates have been theoretically studied from gas to solid to search for new potential high energy density compounds (HEDCs). The heats of formation (HOFs) for the 26 title compounds were calculated by designing isodesmic reactions at the B3LYP/6-31G * level. It was found that the HOFs of the 26 isomers with the same number of ONO 2 groups (n) are not correlated well with the corresponding substituted positions. According to the obtained heats of detonation (Q), detonation velocities (D), and detonation pressures (P) using the Kamlet-Jacobs equations, it was found that when n=7~8, the adamantyl nitrates meet the criterion as an HEDC. The calculations on bond dissociation energies of O N (E O N ) showed that the adamantyl nitrates with gemi ONO 2 always have the worst stability among the isomers, and all the adamantyl nitrates with gemi ONO 2 have similar stability. Due to the complexity of their structures, values of E O N do not decrease with the increase of the substituent number n obviously, and the stability of adamantyl nitrates is not determined by only one structural parameter. Considering the stability requirement, only 1,2,4,6,8,9,10-adamantyl heptanitrate is recommended as a feasible HEDC. Molecular packing searching for 1,2,4,6,8,9,10-adamantyl heptanitrate among 7 most possible space groups (P2 1 /c, P-1, P2 1 2 1 2 1 , P2 1 , Pbca, C2/c, and Pna2 1 ) using Compass and Dreiding force fields showed that this compound tends to crystallize in P2 1 /c. Ab initio periodic calculations on the electronic structure of the predicted packing showed that the O NO 2 bond is the trigger bond during thermolysis, which agrees with the result derived from the study of dissociation energies of O N bonds.high energy density compound (HEDC), adamantyl nitrate, molecular packing, periodic calculation, energetic property, density of states (DOS)

Computational studies on tetrazole derivatives as potential high energy materials

“…Isodesmic reaction approach has been employed for the calculation of HOFs of the designed compounds [20][21][22]. Density is being predicted by crystal structure packing calculations as it is superior to the group additive approaches [23][24][25]. Crystal structure prediction tools automatically take into account molecular structure and conformation and crystal packing efficiency.…”

Theoretical studies on the stability, detonation performance and possibility of synthesis of the nitro derivatives of epoxyethane

“…The isodesmic reaction method, which has been employed successfully to predict the gas phase HOFs of many organic compounds with the help of density functional theory (DFT) calculations [31,32] was adopted to predict the HOFs of compounds 1-4 in the gas phase at 298 K: O n (O 2 N) + n CH 4 O + n CH 3 NO 2 (n=1-4)…”

Crystal structure, detonation performance, and thermal stability of a new polynitro cage compound: 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptacyclo [5.5.1.13, 11. 15, 9] pentadecane

“…The empirical Kamlet-Jacobs equations [13] widely employed [2][3][4][14][15][16][17][18][19][20][21][22] to estimate the detonation velocity and detonation pressure, the important parameters reflecting the explosive performance of energetic materials were used: …”

“…Some candidates of HEDMs with cage structures, e. g., hexanitrohexaazaisowurtzitane (CL-20), polynitroadamantanes, octanitrocubane, and 4-trinitroethyl-2, 6, 8, 10, 12-pentanitrohexaazaisowurtzitane (TNE-CL-20) have been developed and studied [1][2][3][4][5][6][7][8]. They possess characteristics of good explosives, such as high positive heat of formation (HOF), good thermal stability, high crystal density, and enhanced oxygen balance by nitro groups.…”