Synthesis, X-Ray Crystallography, Theoretical Investigation and Optical Properties of 2-Chloro-N-(2,4-dinitrophenyl) Acetamide

Abstract

2-Chloro-N-(2,4-dinitrophenyl) acetamide, 1, was synthesized and characterized by 1H and 13C NMR spectroscopy, ESI–MS, X-ray crystallography, and elemental analysis. This compound crystallizes in the monoclinic space group P21/n. The crystal structure of compound 1 revealed the intramolecular H-bonding with the S(6) motif between H atom of the amide group and the nitro group at the ortho position. Several intermolecular C–H⋯O interactions hold different molecules of the compound 1 together resulting in the crystal packing. Red faint spots observed in the Hirshfeld surface of the compound 1 confirm the presence of N–H⋯O hydrogen bond as well as C–H⋯O interactions. According to the Hirshfeld surface, C–H⋯Cl interaction is also found, of which distance is relatively longer than the C–H⋯O distance. Moreover, the analysis of the corresponding fingerprint plots indicates the significant interactions within the crystal namely H⋯O/O⋯H (39.0%), C⋯O/O⋯C (10.6%), H⋯Cl/Cl⋯H (8.5%), H⋯H (7.3%), and H⋯C/C⋯H (5.9%) contacts. The optical properties of compound 1 in various solvents were investigated using UV–vis spectrophotometry. Compound 1 showed solvatochromic effects upon the varying polarity of the solvent. Time-dependent DFT calculations (TD-DFT) of compound 1 suggest that the deprotonation process occurs in polar solvents such as DMF. Crystal structure of 2-Chloro-N-(2,4-dinitrophenyl) acetamide (1) revealed the intramolecular N–H⋯O hydrogen bonding with the S(6) motif within the molecule as well as several intermolecular C–H⋯O interactions between molecules. Moreover, the compound 1 exhibited solvatochromic effects upon the varying polarity of the solvents.