Structural investigation of the crystallisation nucleant formed between 2,4,6 trinitrotoluene, TNT and 2,2′,4,4′,6,6′ hexanitrostilbene, HNS

Abstract HNS nucleant, effective for TNT crystallisation & prepared from 3% HNS mixtures in molten TNT heated to 160 °C, has been examined by spectroscopic and x-ray diffraction methods. Solution UV/Visible spectra of pure nucleant were identical with mixtures of TNT and HNS. Powder x-ray diffraction patterns of the product differed from those of TNT and HNS and corresponded to unit cell parameters:- a = 10.685 Å, b = 5.684 Å, c = 14.421 Å, B = 104.18°, V = 849.17 Å3, Z = 2. The ‘a’ unit cell dimension is half that of normal HNS and the β angle is reduced giving 2 molecules per cell. This pattern can be interpreted on the basis of a solid solution of TNT in HNS. The additional TNT in the HNS structure may remove the difference between the ‘A’ and ‘B’ type HNS molecules or modify the stacking sequence of the HNS molecules.