Shedding Light on the Synthesis, Crystal Structure, Characterization, and Computational Study of Optoelectronic Properties and Bioactivity of Imine derivatives

Polymorphs of Substituted p-Toluenesulfonanilide: Synthesis, Single-Crystal Analysis, Hirshfeld Surface Exploration, and Theoretical Investigation

Polymorphism is an exciting feature of chemical systems where a compound can exist in different crystal forms. The present investigation is focused on the two polymorphic forms, triclinic (MSBT) and monoclinic (MSBM), of ethyl 3-iodo-4-((4-methylphenyl)sulfonamido)benzoate prepared from ethyl 4-amino-3-iodobenzoate. The prepared polymorphs were unambiguously confirmed by single-crystal X-ray diffraction (SC-XRD) analysis. According to the SC-XRD results, the molecular configurations of both structures are stabilized by intramolecular N-H···I and C-H···O bonding. The crystal packing of MSBT is different as compared to the crystal packing of MSBM because MSBT is crystallized in the triclinic crystal system with the space group P1̅, whereas MSBM is crystallized in the monoclinic crystal system with the space group P21/c. The molecules of MSBT are interlinked in the form of dimers through N-H···O bonding to form R22(8) loops, while the MSBM molecules are connected with each other in the form of an infinite chain through C-H···O bonding. The crystal packing of both compounds is further stabilized by off-set π···π stacking interactions between phenyl rings, which is found stronger in MSBM as compared to in MSBT. Moreover, Hirshfeld surface exploration of the polymorphs was carried out, and the results were compared with the closely related literature structure. Accordingly, the supramolecular assembly of these polymorphs is mainly stabilized by noncovalent interactions or intermolecular interactions. Furthermore, a density functional theory (DFT) study was also carried out, which provided good support for the SC-XRD and Hirshfeld studies, suggesting the formation of both intramolecular and intermolecular interactions for both compounds.

New platinum (II) complexes based on schiff bases: synthesis, specification, X-ray structure, ADMET, DFT, molecular docking, and anticancer activity against breast cancer

Acylpyrazolone-based Schiff base ligands (HLⁿ) and their corresponding Pt(II) complexes with the general formula [Pt(Lⁿ)(Cl)] (n = 1-3) were synthesized and characterized by different spectroscopic techniques including ¹H-NMR, ¹⁹⁵Pt-NMR, LC-Mass, FT-IR, and UV-Vis spectroscopy, as well as elemental analysis. The crystal structure of one of the Schiff base ligands was also obtained. Based on the ADMET comparative results and the bioavailability radar charts, the complexes are completely drug-like. The Schiff base complexes with a structural difference of one methyl group in ligand were used as anticancer agents against human breast cancer cell lines SKBR3 and MDA-MB-231. The IC₅₀ values after treatment by [Pt(L¹)Cl] and [Pt(L²)Cl] were obtained more than cisplatin and less than carboplatin on cancer cells MDA-MB-231 and SKBR3, while the IC₅₀ value of [Pt(L³)Cl] was more than both other complexes and clinical Pt drugs. Molecular docking data showed that the groove binding is the main interaction with DNA double strands with a minor contribution from electrostatic interactions. To investigate the structure-activity relationship, DFT computational was done. All quantum chemical parameters display the drug approaching biomacromolecule and more biological activity of [Pt(L¹)Cl] > [Pt(L²)Cl] > [Pt(L³)Cl]. So, three Schiff base platinum complexes can be suitable candidates as anticancer drugs. Schiff-base ligands (HLn) and their Pt(II) complexes ([Pt(Ln)(Cl)], n=1-3) were obtained. To investigate their biological property and main interactions with DNA, ADMET, and cytotoxicity against MDA-MB-231 and SKBR3, DFT, and Molecular docking were done.

Evaluation of optimized molecular structure-antimicrobial and antioxidant efficacy relationship of Schiff bases

The synthesis, reactivity, structure, antimicrobial potential, and antioxidant property of some Schiff bases were extensively studied experimentally and theoretically using the B₃LYP method of DFT (density functional theory). Schiff bases formed with the interaction of salicylaldehyde and amino alcohols in a 1:1 molar ratio in ethanol. The physicochemical and spectroscopic investigations decide the plausible structure of these newly synthesized Schiff bases. The computational study can assess the molecular orbitals, chemical reactivity, stability, and molecular electrostatic potential of Schiff bases. The thermodynamic parameters and optimized structures of Schiff bases in the gaseous state investigated by the B₃LYP method of DFT. The evaluation of Schiff bases possesses antimicrobial resistance against gram-negative (Pseudomonas aeruginosa) and (Bacillus cereus)gram-positive bacterial strains as well as fungal strains (Candida albicans and Penicillium chrysogeum). The MIC (minimum inhibitory concentration) of all Schiff bases against Bacillus cereus was found in the range of 250 to 1200 µg. The MIC values of L₁H, L₂H, and L₃H against Penicillium chrysogeum were 400, 600, and 800 µg, respectively, whereas the MIC value of L₁H against Candida albicans was 600 µg. The free radical scavenging activity by the DPPH method was used to access potential antioxidant activity in Schiff bases.

Synthesis, Structural, and Intriguing Electronic Properties of Symmetrical Bis-Aryl-α,β-Unsaturated Ketone Derivatives

Three symmetrical bis-aryl-α,β-unsaturated ketone derivatives, 2,6-di((E)-benzylidene)-cyclohexan-1-one (DBC), 2,6-bis((E)-4-chlorobenzylidene)cyclohexan-1-one (BCC), and (1E,1'E,4E,4'E)-5,5'-(1,4-phenylene)bis(2-methyl-1-phenylpenta-1,4-dien-3-one) (PBMP), have been prepared using the aldol condensation approach toward ketones having two enolizable sites. The structures of DBC, BCC, and PBMP have been resolved via spectrometric methods. Moreover, the crystal structure of PBMP is determined by the single-crystal X-ray diffraction (SC-XRD) technique, which revealed that the PBMP molecular assembly is stabilized by the intermolecular C-H···O bonding and C-O···π and weak T-shaped offset π···π stacking interactions. The Hirshfeld surface analysis (HSA) of the PBMP crystal structure was performed as well, and the results were compared with the results of DBC and BCC. The density functional theory (DFT) study results revealed that the longer conjugated molecule of PBMP has smaller but still quite significant HOMO-LUMO gaps compared to the smaller molecules of BCC and DBC. The natural population analysis (NPA) and natural bonding orbital (NBO) analysis were performed. Accordingly, the hydrogen bonding and dipole-dipole interactions stabilize the crystal structures of these compounds. Additionally, the NBO analysis showed numerous high-energy stabilizing interactions for the PBMP compound due to the presence of numerous delocalized and relatively easily polarizable π-electrons, thus implying its significant thermodynamic stability. According to the global reactivity parameter (GRP) analysis, the compounds BCC and DBC are relatively stable in redox processes and have high thermodynamic stability and relatively lower reactivity in general. The molecular electrostatic potential (MEP) analysis results imply potential formation of the intermolecular hydrogen bonding and dispersion interactions, which stabilizes the crystal structures of these compounds.