Hydrogen‐Bonding Interactions and Properties of Energetic Nitroamino[1,3,5]triazine‐Based Guanidinium Salts: DFT‐D and QTAIM Studies

Abstract

The intramolecular hydrogen-bonding interactions and properties of a series of nitroamino[1,3,5]triazine-based guanidinium salts were studied by using the dispersion-corrected density functional theory method (DFT-D). Results show that there are evident LP(N or O; LP = lone pair)→σ*(N-H) orbital interactions related to O⋅⋅⋅H-N or N⋅⋅⋅H-N hydrogen bonds. Quantum theory of atoms in molecules (QTAIM) was applied to characterize the intramolecular hydrogen bonds. For the guanidinium salts studied, the intramolecular hydrogen bonds are associated with a seven- or eight-membered pseudo-ring. The guanylurea cation is more helpful for improving the thermal stabilities of the ionic salts than other guanidinium cations. The contributions of different substituents on the triazine ring to the thermal stability increase in the order of -NO(2)<-NF(2)<-N(3) (-ONO(2))<-NH(2). Energy decomposition analysis shows that the salts are stable owing to electrostatic and orbital interactions between the ions, whereas the dispersion energy has very small contributions. Moreover, the salts exhibit relatively high densities in the range of 1.62-1.89 g cm(-3). The detonation velocities and pressures lie in the range of 6.49-8.85 km s(-1) and 17.79-35.59 GPa, respectively, which makes most of them promising explosives.

Insensitive ionic bio-energetic materials derived from amino acids

“…The hydrogen bond plays an important role in increasing the density and decreasing the sensitivity of energetic compounds 50 , 51 . The structures of [Gly]ClO 4 and [Ala]NO 3 were characterized by single-crystal X-ray diffraction (Fig.…”

Theoretical studies on the stability of the salts formed by DTDO with HNO 3 and HN(NO 2 ) 2

“…[10][11][12] In order to comprehensively reveal the effects of conformations on intramolecular interactions and stability, various intramolecular interactions were predicted and results are tabulated in table 2, the variation trends of these parameters are plotted in figure 2.…”

“…Previous studies have shown that orbital interaction diagrams can reflect the relationships between the orbitals of salts and the isolated ions. [10][11][12] The orbital figure 5. Figure 5 clearly shows the contributions from the orbitals of the isolated anion and cation to the orbitals of salts.…”

“…Our previous studies 10,11 have shown that the stability and density are tightly related to intramolecular interactions, which can be reflected by the hydrogen bonding interaction (E H ), the charge transfer (q), the binding energy (E b ), and the second-order perturbation energy (E 2 ), etc., between the cation and anion. 11,12 In this paper, these interactions in salts 1 and 2 were evaluated. The frontier molecular orbitals and UV spectra were also computed to estimate the effects of conformations on chemical and UV stabilities.…”

A theoretical study on the stability and detonation performance of 2,2,3,3‐tetranitroaziridine (TNAD)

“…, the LUMO (lowest unoccupied molecular orbital) of TNAD has lower energy than TNAZ and TNAD has a slightly higher Δ E g (5.22 eV) than TNAZ (5.06 eV). According to the previous study, TNAD should have a slightly lower chemical reactivity than TNAZ. And for TNAD and TNAZ, the atomic orbitals of C and N in the skeleton all participate in HOMO (highest occupied molecular orbital), but not LUMO.…”