Reversible phase transition in semi-organic compound p-Nitroanilinium sulfate detected using second harmonic generation as a tool

摘要

Crystals structure of p-Nitroanilinium sulfate, (C6H7N2O2+, HSO4-) grown from aqueous solution were characterized by single crystal X-ray diffraction at 298 K. This compound crystallizes in P2(1)2(1)2(1) space group of orthorhombic system. The structure is built by chains formed by (NH3C6H4NO2+) organic cations between which are situated the sulfate mineral anions (HSO4-). The thermal analyses were realized by differential scanning calorimetry (DSC) technique which indicated that the p-Nitroanilinium sulfate present a reversible phase transition at T-c = 338(2) K. The SHG measurements were realized at room temperature as well as with temperature depending. During heating and cooling processes the second harmonic signals show a reversible phase transition at 57 degrees C. These results are in good agreement with the results obtained from DSC measurements. (C) 2015 Elsevier B.V. All rights reserved.