Synthesis, crystal structure, spectroscopic and computational investigations of the newly synthesized Schiff bases scaffold as enzyme inhibitor.

The current project was planned to access the enzyme inhibition potential of the synthesize imines; (E)-2-(2-hydroxy-4,5-dimethoxybenzylideneamino)benzonitrile 1 and (E)-2-(((3-hydroxy-4-methylphenyl)imino)methyl)-4-methoxyphenol 2 by the reported protocol of our continuous research and also assess their theoretical function in term of in silico action. The structural characterization of imines was done through advanced techniques i.e., FTIR, 1H NMR, 13C NMR, and UV spectroscopy. Moreover, a single X-Ray diffraction technique (SCXRD) was employed for real structural identification of imines dimensions, which revealed that compound 1 has a triclinic crystal system although 2 has a monoclinic one. A 2D fingerprint plot and Hirshfeld surface analysis (HS) was employed in the crystalline assembly of compounds to check intermolecular contacts and also their degree of contributions. Both compounds were optimized by B3LYP functional mode using a certain basis set (6-31G). The practical data (XRD) and theoretical data (DFT) of both molecules were compared and found between a sound coherence. Molecular docking studies in term of in silico assessment were conducted against enzymes of the esterase and alpha-glucosidase family. The docking outputs give a forecast about compounds that could be employed as protein inhibitors against analyzed protein surfaces.

Crystal structure and Hirshfeld surface analysis of dimethyl 3,3'-{[(1E,2E)-ethane-1,2-diyl-idene]bis(aza-nylyl-idene)}bis-(4-methyl-benzoate).

The title Schiff base compound, C20H20N2O4, synthesized by the condensation reaction of methyl 3-amino-4-methyl-benzoat and glyoxal in ethanol, crystallizes in the the monoclinic space group P21/n. The mol-ecule is Z-shaped with the C-N-C-C torsion angle being 47.58 (18)°. In the crystal, pairs of mol-ecules are linked via C-H⋯N hydrogen bonds, forming centrosymetric dimers with an R 2 2(8) ring motif; this connectivity leads to the formation of columns running along the a-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to explore the inter-molecular inter-actions and revealed that the most significant contributions to the crystal packing are from H⋯H (49.4%), H⋯O/O⋯H (19.0%) and H⋯C/C⋯H (17.5%) contacts. Energy frameworks were constructed through different inter-molecular inter-action energies to investigate the stability of the compound. The net inter-action energies for the title compound were found to be electrostatic (E ele = -48.4 kJ mol-1), polarization (E pol = -9.7 kJ mol-1), dispersion (E dis = -186.9 kJ mol-1) and repulsion (E rep = 94.9 kJ mol-1) with a total inter-action energy, E tot, of -162.4 kJ mol-1.

Crystal structure and Hirshfeld surface analysis of 6,6'-((1E,1'E)-{[1,4-phenyl-enebis(methyl-ene)]bis(aza-nylyl-idene)}bis-(methane-ylyl-idene))bis-(2-meth-oxy-phenol).

The Schiff base compound, C24H24N2O4, was synthesized by the inter-action of 2-hy-droxy-3-meth-oxy benzaldehyde and 1,4-benzene dimethanamine in ethanol, and crystallizes in the monoclinic space group P21/n with Z' = 0.5. The mol-ecule is not planar, the 1,4-di-ethyl-benzene and the phenol rings are twisted with respect to each other, making a dihedral angle of 74.27 (5)°. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, resulting in the formation of sheets parallel to the bc plane. A Hirshfeld surface analysis was undertaken to investigate the various inter-molecular contacts controlling the supra-molecular topology, suggesting the H⋯O (18%) contacts to be the most significant inter-actions, whereas the H⋯H (50.5%) and C⋯H (24.3%) inter-actions are less significant.

Synthesis, crystal structure and Hirshfeld surface analysis of 1,7-dimethyl-5a,6,11a,12-tetra-hydro-benzo[b]benzo[5,6][1,4]oxazino[2,3-e][1,4]oxazine.

Mol-ecules of the title compound, C16H16N2O2, occupy special positions on the twofold rotation axes. The heterocyclic ring adopts a slightly twisted envelope conformation with one of the two junction carbon atoms as the flap. The mean planes through the two halves of the mol-ecule form a dihedral angle of 72.01 (2)°. In the crystal, mol-ecules are linked by pairs of C-H⋯O and N-H⋯C contacts into layers parallel to (100). H⋯H contacts make the largest contribution to the Hirshfeld surface (58.9%).