Structural, spectroscopic and thermal characterizations combined with DFT calculations and Hirshfeld analysis of a novel hydrogen-bonded complex: p-phenylenediammonium dinitrate

The compound p-phenylenediammonium dinitrate (PPDN) has been synthesized and its structure characterized by FT-IR, Raman and single crystal XRD techniques. Thermal behavior of this compound has been studied by TGA/DSC analysis. The three-dimensional framework observed in the PPDN structure is mainly maintained thanks to conventional N-HO hydrogen bonds and weak C-H center dot center dot center dot O contacts. In the p-phenylenediammonium cation, four carbon atoms of the aromatic ring are disordered over two positions with half occupancy. The geometry, modes of vibrations, atomic charges, thermodynamic parameters and frontier molecular orbitals of the PPDN molecule have been calculated by DFT method at B3LYP/6-311(++)G(d,p) and B3LYP/cc-pVTZ levels. The intermolecular bonding interactions within this molecule have been investigated using the natural bonding orbital (NBO) analysis at B3LYP/cc-pVTZ level. The 3-D Hirshfeld surface and the associated 2-D fingerprint plot, calculated for the PPDN molecule, have showed the clearly dominance of the H center dot center dot center dot O/O center dot center dot center dot H and H center dot center dot center dot H contacts which together represent more than 80% of the total surface. (C) 2019 Elsevier B.V. All rights reserved.