Crystal structure, Hirshfeld surface analysis and computational study of 2-chloro-N-[4-(methyl-sulfanyl)phenyl]acetamide

In the title compound, C9H10ClNOS, the amide functional group-C(=O)NH-adopts a trans conformation with the four atoms nearly coplanar. This conformation promotes the formation of a C(4) hydrogen-bonded chain propagating along the [010] direction. The central part of the molecule, including the six-membered ring, the S and N atoms, is fairly planar (r.m.s. deviation of 0.014). The terminal methyl group and the C(=O)CH2 group are slightly deviating out-of-plane while the terminal Cl atom is almost in-plane. Hirshfeld surface analysis of the title compound suggests that the most significant contacts in the crystal are H center dot center dot center dot H, H center dot center dot center dot Cl/Cl center dot center dot center dot H, H center dot center dot center dot C/C center dot center dot center dot H, H center dot center dot center dot O/O center dot center dot center dot H and H center dot center dot center dot S/S center dot center dot center dot H. pi-pi interactions between inversion-related molecules also contribute to the crystal packing. DFT calculations have been performed to optimize the structure of the title compound using the CAMB3LYP functional and the 6-311 G(d,p) basis set. The theoretical absorption spectrum of the title compound was calculated using the TD-DFT method. The analysis of frontier orbitals revealed that the pi-pi* electronic transition was the major contributor to the absorption peak in the electronic spectrum.