Study of Physicochemical and Explosive Properties of a 2,4,6-Trinitrotoluene/Aniline Cocrystal Solvate

In the development of crystal engineering and supramolecular chemistry, cocrystallization has been used as a way to develop novel explosives with tailored properties. We present a novel cocrystal solvate composed of 2,4,6-trinitrotoluene (TNT) and aniline that exhibits unique physicochemical and explosive properties. X-ray diffraction studies reveal the crystallographic structure to contain TNT and aniline in a 1:1 molecular ratio. The crystals themselves exhibit a vibrant, ruby red color that likely results due to a charge-transfer interaction between the overlapping pi-orbitals of the aromatic rings. The most notable evidence for a charge-transfer complex is the appearance of a broad absorbance peak in the visible region which is not present in the spectrum of either pure component. Comparisons of the cocrystal solvate to that of pure TNT are conducted to determine thermodynamic and kinetic parameters using both experimental and theoretical techniques. The desolvation of aniline from the cocrystal solvate was also investigated using both in situ powder X-ray diffraction and atomic force microscopy measurements to monitor changes in the crystal structure and surface topography, respectively.