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

Sitthichok Mongkholkeaw; Apisit Songsasen; Tanwawan Duangthongyou; Kittipong Chainok; Songwut Suramitr; Worawat Wattanathana; Boontana Wannalerse

doi:10.1107/S2056989020002960

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

Acta Crystallogr E Crystallogr Commun. 2020 Mar 31;76(Pt 4):594-598. doi: 10.1107/S2056989020002960. eCollection 2020 Apr 1.

Authors

Sitthichok Mongkholkeaw¹, Apisit Songsasen¹, Tanwawan Duangthongyou¹, Kittipong Chainok², Songwut Suramitr³, Worawat Wattanathana⁴, Boontana Wannalerse¹

Affiliations

¹ Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
² Materials and Textile Technology, Faculty of Science and Technology, Thammasat University, Pathum Thani, 12120, Thailand.
³ Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
⁴ Department of Materials Engineering, Faculty of Engineering, Kasetsart University Bangkok, 10900, Thailand.

Abstract

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 mol-ecule, 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⋯H, H⋯Cl/Cl⋯H, H⋯C/C⋯H, H⋯O/O⋯H and H⋯S/S⋯H. π-π inter-actions between inversion-related mol-ecules also contribute to the crystal packing. DFT calculations have been performed to optimize the structure of the title compound using the CAM-B3LYP 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 π-π* electronic transition was the major contributor to the absorption peak in the electronic spectrum.

Keywords: 4-methylthioaniline; chloroacetyl chloride; crystal structure; hydrogen bonds; π–π interactions.