Comparative investigation of derivatives of (E)-N-((E)-3-phenylallylidene)aniline: Synthesis, structural characterization, biological evaluation, density functional theory analysis, and in silico molecular docking.

Bacterial resistance to antibiotics poses a significant global challenge for the public sector. Globally, researchers are actively investigating solutions to tackle the issue of bacterial resistance to antibiotics, with Schiff bases standing out as promising contenders in the fight against antimicrobial resistance. This study focused on synthesizing a series of Schiff bases (CA1-CA10) by reacting cinnamaldehyde with various aniline derivatives. Various analytical techniques, such as NMR, FTIR, UV-Vis, elemental analysis, and mass spectrometry, were employed to elucidate the structures of the synthesized compounds. Furthermore, crystal structure of CA8 was obtained using single crystal X-ray spectroscopy. The compounds were subjected to in vitro testing to assess their antibacterial and antifungal properties against eleven bacterial strains and four fungal strains. The results revealed diverse activity levels against the pathogens at varying concentrations, with notable potency observed in compounds CA3, CA4, CA9, and CA10, as indicated by their minimum inhibitory concentrations (MIC) values. The observed activity of the compounds seemed to be influenced by the specific substituents attached to their molecular structure. By conducting computational and molecular docking studies, the electronic properties of the compounds were investigated, further substantiating their potential as effective antimicrobial agents.

(2,2'-Bipyrid-yl)(η6-p-cymene)iodidoruthenium(II) hexa-fluorido-phosphate.

The title compound, having the mol-ecular formula [RuI(η6-C10H14)(C10H8N2)]PF6, crystallizes in the triclinic P (Z = 2) space group as a half-sandwich complex resembling a three-legged piano stool. Important geometrical parameters include Ru-cymene centroid = 1.6902 (17) Å, Ru-I = 2.6958 (5) Å, [Ru-N]avg = 2.072 (3) Å, N1-Ru-N2 = 76.86 (12)° and a dihedral angle between the planes of the two rings of the bipyridyl system of 5.9 (2)°. The PF6 - ion was treated with a twofold disorder model, refining to a 65.0 (8):35.0 (8) occupancy ratio. The crystal packing features C-H⋯F/I inter-actions.

trans-Bis[bis-(di-phenyl-phosphan-yl)methane-κ2P,P']di-chlorido-ruthenium(II): a triclinic polymorph.

The title compound, [RuCl2(C25H22P2)2] or [RuCl2(dppm)2] (dppm = bis-(di-phenyl-phosphan-yl)methane, C25H22P2) crystallizes as two half-mol-ecules (completed by inversion symmetry) in space group P (Z = 2), with the RuII atoms occupying inversion centers at 0,0,0 and 1/2, 1/2, 1/2, respectively. The bidentate phosphane ligands occupy equatorial positions while the chlorido ligands complete the distorted octa-hedral coordination spheres at axial positions. The bite angles of the phosphane chelates are similar for the two mol-ecules [(P-Ru-P)avg. = 71.1°], while there are significant differences in the twisting of the methyl-ene backbone, with a distance of the methyl-ene C atom from the RuP4 plane of 0.659 (2) and 0.299 (3) Å, respectively, and also for the phenyl substituents for both mol-ecules due to variations in weak C-H⋯Cl inter-actions.

Crystal, spectroscopic and quantum mechanics studies of Schiff bases derived from 4-nitrocinnamaldehyde.

Two Schiff bases, (E)-1-(4-methoxyphenyl)-N-((E)-3-(4-nitrophenyl)allylidene)methanamine (compound 1) and (E)-N-((E)-3-(4-nitrophenyl)allylidene)-2-phenylethanamine (compound 2) have been synthesized and characterized using spectroscopic methods; time of flight MS, 1H and 13C NMR, FT-IR, UV-VIS, photoluminescence and crystallographic methods. The structural and electronic properties of compounds 1 and 2 in the ground state were also examined using the DFT/B3LYP functional and 6-31 + G(d,p) basis set, while the electronic transitions for excited state calculations were carried out using the TD-DFT/6-31 + G(d,p) method. The Schiff base compounds, 1 and 2 crystallized in a monoclinic crystal system and the P21/c space group. The emission spectra of the compounds are attributed to conjugated π-bond interaction while the influence of the intra-ligand charge transfer resulted in a broad shoulder for 1 and a double emission peak for 2. The calculated transitions at 450 and 369 nm for 1 and 2 respectively are in reasonable agreement with the experimental results. The higher values of dipole moment, linear polarizability and first hyperpolarizability of 1, suggest a better optical property and better candidate for the development of nonlinear optical (NLO) materials.