Experimental and theoretical study on the molecular structure, covalent and non-covalent interactions of 2,4-dinitrodiphenylamine: X-ray diffraction and QTAIM approach

Single-crystal X-ray diffraction (SCXRD) experiments and theoretical calculations based on the Quantum Theory of Atoms in Molecules (QTAIM) approach have been used to analyse the characteristics of the covalent and the non-covalent interactions of 2,4-dinitrodiphenylamine (2,4-dna), also known as Serisol-Yellow 2G. DSC-TGA experiments were also carried out to obtain data on the thermal stability of the entitled compound. SCXRD and QTAIM results showed that 2,4-dna molecules form centrosymmetric dimers linked by unusual O⋯O intermolecular interactions with short contact distances (2.73 Å) that are accompanied by C[sbnd]H⋯O and N[sbnd]H⋯O intermolecular interactions. Due to the number of -CH groups available in 2,4-dna, the molecular self-assembly continues through C[sbnd]H⋯O intermolecular interactions, which also contribute with the stabilization of the supramolecular network. The analysis of the ESP map revealed that the most positive region of the -CH groups bound to the most negative -NO₂ group forming a R₂²(7) synthon. DSC-TGA analysis revealed that 2,4-dna is stable up to 150 °C.