New polymorph of N-benzoyl-morpholine-4-carbothioamide with ten crystallographically independent molecules in the asymmetric unit: Crystal structure, Hirshfeld surface analysis and Density functional theory calculations

Abstract

Herein, facile synthesis, single crystal X-ray diffraction (SC-XRD) structure, Hirshfeld surface (HS) analysis and Density functional theory (DFT) calculations of N-benzoyl-morpholine-4-carbothioamide 5(a) are presented. Hence, the synthesized compound, C12H14N2O2S 5(a), crystallizes in monoclinic crystal system having space group of P 21 with a = 22.2226 (9) Å, b = 11.7520 (3) Å, c = 24.9361 (8) Å, α = 90°, β = 111.054 (4)°, γ = 90°, Z = 20 and V = 6077.6 (4) Å3. The asymmetric unit of 5(a) contains ten crystallographically independent molecules, where the morpholine and benzene rings are in respective chair and planar conformations. In the crystal structure, some of the intermolecular, N—H···O, C—H···O and C—H···S, hydrogen bonds link the molecules into a 2D-network parallel to (010), enclosing R22(10) and R22(24) ring motifs, when viewed down the b-axis direction. Furthermore, contribution of the remaining hydrogen bonds consolidates a 3D-architecture. Similarly, HS analysis clarified the importance of hydrogen atom contacts with the major contributions of H…H (46.7 %), H…S/S…H (21.1 %), H…C/C…H (16.5 %), and H…O/O…H (12.5 %). Thus, hydrogen bond and van der Waals interactions play major role in the crystal packing. Finally, optimum molecular structure of compound 5(a) was related to the experimentally determined one employing DFT at B3LYP/6–311++G(d,p) level. Subsequently, the geometry of the optimized and most stable conformation turned out to be complementary with the crystal structure. The computational calculation of compound 5(a) revealed the molecule to be chemically hard in nature with high energy intrinsic reaction pathway. The associated band gap predicted compound 5(a) to be a wide band gap material. The intrinsic reaction pathway predicts hard-core behavior of the molecule.