Investigation of Structure–Property Relationships of Three Nitroaromatic Compounds: 1-Fluoro-2,4,6-trinitrobenzene, 2,4,6-Trinitrophenyl Methanesulfonate, and 2,4,6-Trinitrobenzaldehyde

Abstract

Recently the investigation of the correlation between the crystal structure and important properties such as the sensitivity and thermostability of energetic materials has gained more and more interest among experts in the field. To contribute to this development, several models for the sensitivity prediction of energetic materials have been applied to the title compounds. Very often, older models that focus on bond dissociation enthalpy or electrostatic potential result in values that differ significantly from values of actual measurements. However, more recent models such as Hirshfeld surface analysis and fingerprint plot analysis offer an improved correlation between prediction and practical tests. We compared these methods with the aforementioned older models and gained further insight into the structure−property relationships of energetic materials. The accuracy of predictions of structure− property relationships that can be deduced from a crystal structure increases with the sample size over time. Therefore, this method should be pursued and applied to different energetic materials in the future, for a better understanding of those relationships.

Synthesis and Characterization of Geminal Diazido Derivatives Based on Diethyl Malonate

“…All bond lengths comply with the expected values for CÀ C, CÀ N, CÀ O and NÀ N single and double bonds. [23,24] Hirshfeld analysis showed a high percentage of N…O contacts (41.2 %) which have a destabilizing effect (Figure 4). [25,26,27] A stabilizing effect is the N…H interaction (21.0 %) but the distance is large (> 3 Å) and can be neglected.…”

Vibrational Analysis of Benziodoxoles and Benziodazolotetrazoles

“…Based on LVM analysis, I−N is most likely the trigger bond responsible for initiation of explosive decomposition in BIATs 5-8. For comparison, trigger bonds were recently identified as C−N bonds in the high-energy compounds 1fluoro-2,4,6-trinitrobenzene and 2,4,6-trinitrobenzaldehyde [31]. Our calculations predict the C−C bond linking Ar and aldehyde groups to be the weakest in the latter, but both bonds in question have k a values between 3.400 and 3.900 mDyn/Å, whereas the possible I−N trigger bonds, I−C, and I−O bonds in this work have k a values between 1.300 and 2.620 mDyn/Å.…”

“…However, they did not find any significant correlation between ∆H d and structural parameters (e.g., lengths of either of the HV bonds or L−I−N valence angles), nucleophilicity, or field electronic parameters of the ligand [25]. It has been suggested that crystal packing in the solid state, i.e., the shearing force between packing layers may well account for the (in)stability of TZs, influencing both temperatures of decomposition and ∆H d , which complicates any direct comparison between ∆H d and structural parameters [31][32][33]. A common way to answer this question from a theoretical perspective is to use bond dissociation energies (BDE) [34,35] as a tool to identify the so-called trigger bond, which is first to break and therefore assesses the stability of a material [36].…”

A Study of 3,5‐Dinitro‐1‐(2,4,6‐trinitrophenyl)‐1H‐pyrazol‐4‐amine (PicADNP) as a New High Energy Density Booster Explosive

“…The ortho nitro groups of the benzene ring show torsion angles of 38.9°(C2-nitro) and 18.8°(C6-nitro), which is a very common observation for trinitrobenzene derivatives. [17,18] This behavior is usually explained by a combination of steric effects and electronic repulsion between the substituent at the 1-position and the ortho nitro groups. [17,18] For PicADNP, the discussed torsion of the substituents facilitates a minimization of the repulsion between neighboring nitro groups and reduces the repulsion between the pyrazole ring and the C2-nitro group.…”

“…As a general trend for insensitive molecules it was found, that the individual planes of their Hirshfeld surface feature red dots which represent close contacts that are located within the plane of the molecule and therefore in a stabilized layer. [15,17,18] In contrary, an increased amount of red dots that point out of the molecular plane is typical for more sensitive materials. [15,17,18] PicADNP exhibits various of those red dots, which point out of the molecular plane (Figure 4) and therefore the material is considered sensitive.…”