X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid

The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P21/c, with a = 14.947 Å, b = 6.432 Å, c = 19.609 Å and Z = 4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods.

Graphical abstractThe X-ray diffraction of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) have been investigated. The crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P21/c, with a = 14.947 Å, b = 6.432 Å, c = 19.609 Å and Z = 4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. Quantum chemical studies performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ, 6-31G and 6-31++G basis sets. The existence of hydrogen bonding has been analysed.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► X-ray diffraction of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) has been analysed. ► The crystals are monoclinic, space group P21/c, with a = 14.947  Å, b = 6.432  Å, c = 19.609  Å and Z = 4. ► FTIR and FT-Raman investigations of the molecular complex were carried out. ► Energy, structural, thermodynamical and vibrational characteristics were determined. ► The existences of different types of hydrogen bondings have been investigated.