Crystal engineering of high explosives through lone pair-π interactions: Insights for improving thermal safety

Matteo Savastano; María Dolores López de la Torre; Marco Pagliai; Giovanna Poggi; Francesca Ridi; Carla Bazzicalupi; Manuel Melguizo; Antonio Bianchi

doi:10.1016/j.isci.2023.107330

Crystal engineering of high explosives through lone pair-π interactions: Insights for improving thermal safety

iScience. 2023 Jul 10;26(9):107330. doi: 10.1016/j.isci.2023.107330. eCollection 2023 Sep 15.

Authors

Matteo Savastano^{1

2}, María Dolores López de la Torre³, Marco Pagliai², Giovanna Poggi^{2

4}, Francesca Ridi^{2

4}, Carla Bazzicalupi², Manuel Melguizo³, Antonio Bianchi²

Affiliations

¹ Department of Human Sciences and Quality of Life Promotion, University San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy.
² Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy.
³ Department of Inorganic and Organic Chemistry, University of Jaén, 23071 Jaén, Spain.
⁴ CSGI, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy.

Abstract

In this high-risk/high-reward study, we prepared complexes of a high explosive anion (picrate) with potentially explosive s-tetrazine-based ligands with the sole purpose of advancing the understanding of one of the weakest supramolecular forces: the lone pair-π interaction. This is a proof-of-concept study showing how lone pair-π contacts can be effectively used in crystal engineering, even of high explosives, and how the supramolecular architecture of the resulting crystalline phases influences their experimental thermokinetic properties. Herein we present XRD structures of 4 novel detonating compounds, all showcasing lone pair-π interactions, their thermal characterization (DSC, TGA), including the correlation of experimental thermokinetic parameters with crystal packing, and in silico explosion properties. This last aspect is relevant for improving the safety of high-energy materials.

Keywords: Energy materials; Entropy; Materials science.