Synthesis, Crystal Structure and Cyclic Voltammetric Behavior of N-aroyl-N′-(4′-cyanophenyl)thioureas

Herein, two title compounds, N-benzoyl-N′-(4′-cyanophenyl)thiourea (1) and N-(4-nitrobenzoyl)-N′-(4′-cyanophenyl)thiourea (2) were synthesized in a high yield, via different applications of aroyl isocyanate and 4-aminobenzonitrile. The structure of the prepared compounds was characterized by elemental analysis and FT-IR, 1H, and 13C-NMR spectroscopic methods. The crystal structure of the title compound 1 was determined by an X-ray single-crystal technique and an intramolecular C=O…H-N hydrogen bond and intermolecular C=S…H-N and C=S…H-C hydrogen interactions, which were observed for the crystal structure. The molecular electrostatic potential (MEP) and the Mulliken atomic charges of title compounds 1 and 2 were theoretically calculated and interpreted. Cyclic voltammetric (CV) experiments for the compounds were performed with the glassy carbon electrode. The reduction in potential values of the different functional groups such as nitro and cyano in title compounds were investigated using CV curves.

Roboustness of Hydrogen Bonding in the Construction of Supramolecular Architechures in Protonated Perchlorate Salts

Five new multicomponent salts of perchloric acid with a series of substituted anilines and N-heterocyclic amines namely Diphenylaminium perchlorate (DPAPC) (1), 2, 5-dichloroanilinium perchlorate (25DAP) hydrate (2), 4-Methylanilinium perchlorate (4MAPC) (3), 4-diamino-6-methyl-1, 3, 5-triazin-1-ium hydrogen perchlorate (24DAMTHP) (4) and 8-hydroxyquinolinium hydrogen perchlorate (8HQP) (5) were prepared and structurally characterized. The entire complexes were subjected to FTIR and elemental analysis. A vast family of intermolecular contacts N-H…O, O-H…O, N-H…N and C-H…O were observed, which are key ingredient in the generation of privileged supramolecular self-assemblies appeared as one-dimensional chain, two-dimensional ladder and helix. Cambridge structural Database (CSD) analysis of 52 hits revealed the perchloric acid display higher propensity of ladder architectures. Molecular stability of the complexes were studied by quantum chemical calculations using DFT/B3LYP method with 6-31G(d,p) basis set. Further their relative charge distributions were identified using molecular electrostatic potential map. The use of Hirshfeld surfaces in combination with fingerprint plots was visualized in order to study the closer contacts within the molecule. The relative contribution of whole percentage of interactions associated is highlighted.

Synthesis, Crystal Structure and Theoretical Investigations of (3-(2-Chlorophenyl)-5-Tosyl-1,3,3a,4,5,9b-Hexahydroisoxazolo[4,3-c]Quinolin-3a-yl)Methanamine

In the title compound (3-(2-chlorophenyl)-5-tosyl-1,3,3a,4,5,9b-hexahydroisoxazolo[4,3-c]quinolin-3a-yl)methanamine (3-CPTHIQM), the Thorpe–Ingold effect causes the S atom's tetrahedral geometry to be deformed, with O-S-O and N-S-C angles diverging from ideal tetrahedral values. The crystal packing features C—H⋯O hydrogen-bond inter¬actions.The supramolecular interactions were confirmed and quantified using Hirshfeld surface analysis. Quantum chemical calculations of sulfonamide are calculated at DFT/B3LYP/6-311++G(d,p) basis set. The NLO properties were calculated at the same level of theory. Furthermore, frontier molecular orbitals (FMOs) and molecular electrostatic potential (MEP) surfaces were calculated and analyzed in detail. In a molecular docking study, the investigated sulfonamide compound is evaluated as a new potential cancer inhibitor.

On the Importance of Pnictogen and Chalcogen Bonding Interactions in Supramolecular Catalysis

In this review, several examples of the application of pnictogen (Pn) (group 15) and chalcogen (Ch) bonding (group 16) interactions in organocatalytic processes are gathered, backed up with Molecular Electrostatic Potential surfaces of model systems. Despite the fact that the use of catalysts based on pnictogen and chalcogen bonding interactions is taking its first steps, it should be considered and used by the scientific community as a novel, promising tool in the field of organocatalysis.

On the Importance of Halogen Bonding Interactions in Two X-ray Structures Containing All Four (F, Cl, Br, I) Halogen Atoms

This manuscript reports the synthesis and X-ray characterization of two octahydro-1H-4,6-epoxycyclopenta[c]pyridin-1-one derivatives that contain the four most abundant halogen atoms (Ha) in the structure with the aim of studying the formation of Ha···Ha halogen bonding interactions. The anisotropy of electron density at the heavier halogen atoms provokes the formation of multiple Ha···Ha contacts in the solid state. That is, the heavier Ha-atoms exhibit a region of positive electrostatic potential (σ-hole) along the C–Ha bond and a belt of negative electrostatic potential (σ-lumps) around the atoms. The halogen bonding assemblies in both compounds were analyzed using density functional theory (DFT) calculations, molecular electrostatic potential (MEP) surfaces, the quantum theory of “atom-in-molecules” (QTAIM), the noncovalent interaction plot (NCIplot), and the electron localization function (ELF).

Effect of Metal Oxides and Graphene Upon The Electronic Properties of Polyvinyl Alcohol

Nanomaterials improve the physical and electronic characteristics of polymer matrices, allowing the matrices to be used as low cost, easy to handle sensors. Nano ZnO oxide is forming nanocomposite with PVA modified with graphene. Rather than ZnO other metal oxides are assumed to enhance the electronic properties of PVA modified with graphene (G). Accordingly, Density Function Theory (DFT) was used to analyze model molecules of Polyvinyl Alcohol (PVA) that improved with various metal oxides and graphene quantum dots (GQDs). To show the influence of nanomaterials on PVA matrix behavior, HOMO/LUMO molecular orbitals and Molecular Electrostatic Potential (MESP) mapping were calculated. The B3LYPL/LAN2DZ model was used to calculate the band gap energy ∆E, total dipole moment (TDM), and Molecular Electrostatic Potential (MESP). The obtained results indicated that PVA interacted with MgO, led to a significant improvement in the electrical characteristics. The incorporation of GQDs into PVA/MgO resulted in a novel nanocomposite with good electrical characteristics and a band gap energy ∆E of 0.201 eV, which is intended to be used as a humidity sensor.

Computational repurposing of benzimidazole anthelmintic drugs as potential colchicine binding site inhibitors

Background: Although some benzimidazole-based anthelmintic drugs are found to possess anticancer activity, their modes of binding interactions have not been reported. Methodology: In this study, we aimed to investigate the binding interactions and electronic configurations of nine benzimidazole-based anthelmintics against one of the well-known cancer targets (tubulin protein). Results: Binding affinities of docked benzimidazole drugs into colchicine-binding site were calculated where flubendazole > oxfendazole > nocodazole > mebendazole. Flubendazole was found to bind more efficiently with tubulin protein than other drugs. Quantum mechanics studies revealed that the electron density of HOMO of flubendazole and mebendazole together with their molecular electrostatic potential map are closely similar to that of nocodazole. Conclusion: Our study has ramifications for considering repurposing of flubendazole as a promising anticancer candidate.

A Look at the Spatial Confining Effect on the Molecular Electrostatic Potential (MEP)—A Case Study of the HF and BrCN Molecules

In this theoretical study, we report on the molecular electrostatic potential (MEP) of titled molecules confined by repulsive potentials of cylindrical symmetry mimicking a topology. Our calculations show that the spatial restriction significantly changes the picture of the MEP of molecules in a quantitative and qualitative sense. In particular, the drastic changes in the MEP as a function of the strength of spatial confinement are observed for the BrCN molecule. This preliminary study is the first step in the investigation of the behavior of the MEP of molecular systems under orbital compression.

Molecular electrostatic potential and pattern recognition models to design potentially active pentamidine derivatives against Trypanosoma brucei rhodesiense

Molecular electrostatic potential (MEP) and pattern recognition (PR) were used to draw potentially active pentamidine derivatives against Trypanosome brucei rhodesiense (T. b. rhodesiense). PR models: Principal Component Analysis, PCA model; Hierarchical Cluster Analysis, HCA model; K-Nearest Neighbor, KNN model; Soft Independent Modeling of Class Analogy, SIMCA model; and Stepwise Discriminant Analysis, SDA model, were built by reducing the dimensionality of a data matrix to twenty-eight pentamidine derivatives and allowed the compounds to be classified into two classes: more active and less active, according to their degrees of activity against T. b. rhodesiense. The study outlined that the properties HOMO (highest occupied molecular orbital) energy, VOL (molecular volume), and ASA_P (water accessible surface area of all polar (½qi½³0. 2) atoms) are the most relevant for the construction of the models. The key structural features required for biological activity investigated through MEP were used as guidelines in the design of thirteen new compounds, which were evaluated by PR models as more active or less active against T. b. rhodesiense. The application of PR models indicated nine promising compounds (29, 30, 31, 32, 33, 36, 37, 39, and 40) for synthesis and biological assays.