Synthesis, single crystal X-ray structure determination, Hirshfeld surface analysis, interaction energies, and density functional theory calculations of N,N′-(cyclohexane-1,4-dicarbonothioyl)bis(4-methylbenzamide)

The present research offers convenient synthesis, molecular and crystal structures of C-2 symmetric N,N'-(cyclohexane-1,4-dicarbonothioyl)bis(4-methylbenzamide). The synthesized bis-amide crystallized in mono-clinic crystal system, having space group of P 2(1)/c with a =17.8669 (14) angstrom, b = 6.3495 (5) angstrom, c = 9.6195 (7) angstrom, beta = 101.567 (8)degrees, Z = 2 and V = 1069.13 (15) angstrom(3). The asymmetric unit contains cyclohexane ring located on an inversion center, one dicarbonothioyl and one methylbenzamide group. In the crystal structure, the N-H center dot center dot center dot O, C-H center dot center dot center dot O and C-H center dot center dot center dot S hydrogen bonds link the molecules, enclosing R-2(1)(6), R-2(2)(16) and R-2(2)(22) ring motifs, into three-dimensional architecture. Hirshfeld surface (HS) analysis revealed the prevailing significance of hydrogen bond contacts. HS analysis suggested prominent contributions for crystal packing encompasses H center dot center dot center dot H (49.6%), H center dot center dot center dot C/C center dot center dot center dot H (18.9%) and H center dot center dot center dot S/S center dot center dot center dot H (16.0%). Hydrogen bonding and van der Waals contacts are the dominant interactions in the crystal packing. The respective volume of the crystal voids and the percentage of free spaces in the unit cell is calculated as 117.87 angstrom(3) and 11.02% indicating the absence of any large cavity within the crystal and the associated stability of the crystal. Evaluation of the electrostatic, dispersion and total energy frameworks revealed that stabilization is dominated by dispersion energy contribution. Moreover, optimized molecular structure, using density functional theory at B3LYP/6-311G(d,p) level, were compared with the experimentally determined ones. HOMO-LUMO energy gap was determined, frequencies and molecular electrostatic potential surface were calculated at the B3LYP/6-311G level to predict sites for electrophilic and nucleophilic attacks. The significant charge polarity, half molecule spread of HOMO and LUMO impart bis-amide nucleophilic as well as electrophilic behavior with relative potency depending upon the nature of the attacking molecule.