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.

中文翻译：

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2-氯-N-(2,4-二硝基苯基)乙酰胺的合成、X射线晶体学、理论研究和光学性质

合成了 2-氯-N-(2,4-二硝基苯基) 乙酰胺 1，并通过 1H 和 13C NMR 光谱、ESI-MS、X 射线晶体学和元素分析对其进行了表征。该化合物在单斜空间群 P21/n 中结晶。化合物 1 的晶体结构揭示了分子内 H 键与酰胺基团的 H 原子和邻位硝基之间的 S(6) 基序。几个分子间 C–H⋯O 相互作用将化合物 1 的不同分子结合在一起，导致晶体堆积。在化合物 1 的 Hirshfeld 表面观察到的红色微弱斑点证实了 N–H⋯O 氢键以及 C–H⋯O 相互作用的存在。根据 Hirshfeld 面，还发现了 C-H⋯Cl 相互作用，其距离相对大于 C-H⋯O 距离。而且，对相应指纹图的分析表明晶体内部存在显着的相互作用，即 H⋯O/O⋯H (39.0%)、C⋯O/O⋯C (10.6%)、H⋯Cl/Cl⋯H (8.5%) 、H⋯H (7.3%) 和 H⋯C/C⋯H (5.9%) 接触。使用紫外-可见分光光度法研究了化合物 1 在各种溶剂中的光学性质。化合物 1 对溶剂的不同极性显示出溶剂化变色效应。化合物 1 的时间相关 DFT 计算 (TD-DFT) 表明去质子化过程发生在极性溶剂如 DMF 中。2-氯-N-(2,4-二硝基苯基)乙酰胺(1)的晶体结构揭示了分子内N-H⋯O与分子内S(6)基序的氢键以及几个分子间C-H⋯O分子之间的相互作用。而且，