Narrow Results

This work aims at synthesis and characterization of 2,2${}^{\prime }$-dibenzimidazolyl butane as an effective corrosion inhibitor of mild steel in sulfuric acid solution. A simple and efficient method for its synthesis in described. The chemical structure and surface morphology of 2,2${}^{\prime }$-dibenzimidazolyl butane were characterized by mass spectrometry (MS), Fourier transform infrared (FTIR), Raman, ¹H, ${}^{13}$C NMR spectroscopy and transmission electron microscopy (TEM). Its thermal decomposition and its variation in mass was studied by thermogravimetric analysis (TGA) coupled with differential thermal analysis (DTA). The molecular mass of 2,2${}^{\prime }$-dibenzimidazolyl butane was determined to be at 290g/mol and its degradation was achieved at 455^∘C. Then, the corrosion inhibition efficiency of 2,2${}^{\prime }$-dibenzimidazolyl butane was studied with various concentrations in 0.5 M H₂SO₄ solution for mild steel by the potentiodynamic polarization and the electrochemical measurements. According to the results of electrochemical impedance spectroscopy, the inhibition efficiency decreased with concentration and reached its maximum (95.5%) at 100ppm. The polarization measurements showed that the prepared inhibitor acts as a cathodic type inhibitor. The mass loss tests are in accordance with the results of electrochemical measurements.

In this study the anticancer properties of a series of benzimidazole drugs 1–9 and their interactions with DNA base pairs were investigated. The obtained theoretical results for anticancer activity of synthesized drugs 1–5 were compared to corresponding published experimental results. Based on theoretical and published experimental anticancer scales, drugs 2 and 4 have higher anticancer activity among drugs 1–5. Obtained results reveal that interactions of studied drugs with DNA base pairs are energetically favorable and solvent and electric field (EF) increase the binding energies in comparison to gas phase. The binding energies of drugs 2, 5 and 4 with DNA base pairs are more negative than corresponding values for drug 1. We propose the novel drugs 6–9 to synthesize with higher anticancer activity. Results show that binding energies of novel drugs 6–9 were more negative than drugs 1–5. Finally, results show that chemical potential, electrophilicity and global hardness can be considered as admissible theoretical anticancer indexes for studied benzimidazole drugs 1–9.

The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amine group of 1,3-bis(benzimidazol-2yl)propylamine (BBPAH). The ion exchangers contain 2.71–3.23 mmol of the ligand contents per gram of the resin. Batch extraction capacities were determined for the metal chloride salts in buffer solutions in the pH range from -1 to 6.0. The chelate resins were very selective for Cu²⁺, Zn²⁺, Cd²⁺ in the presence of other divalent transition metal ions. The maximum uptake capacities of PNBMZ (synthetic molar ratio = 1:1.5) under non-competitive condition were found to be 0.94 mmol/g for Cu²⁺ at pH = 2, 1.3 mmol/g for Cd²⁺ at pH = 1 and 1.75 mmol/g for Zn²⁺ at pH = -1 respectively. While in the case of PBBMZ, it was 1.39 mmol/g for Cd²⁺ at pH = 1. The metal-uptake behaviors for both of them showed strong pH dependence, and their extraction capacities increase with decreasing pH. The uptake of Cu²⁺ by the resin PNBMZs at pH = 1 was found to be rather fast with t_1/2 = 18 min. Metal-uptake experiments under competitive conditions also confirm that the chelate resins have a high selectivity for Cu²⁺Zn²⁺, Cd²⁺ and the contrary pH dependence.

We synthesized the hexa-coordinated Re(I) bridged BODIPY dyad 1 in decent yield by thermal reaction of benzimidazole substituted BODIPY 2 with Re(CO)₅Cl. The dyad 1 was characterized by ¹H, ¹³C, ¹¹B, ¹⁹F NMR, ESI-MS, FTIR, UV-vis, and electrochemical techniques. In Re(I) bridged dyad 1, the Re(I) ion is hexa-coordinated and coordinates with nitrogen atoms of two benzimidazole units, three axial carbonyl ligands and one chloride atom. The presence of three carbonyl groups in dyad 1 was verified by ¹³C NMR and IR spectroscopy. The absorption and steady-state fluorescence spectra of Re(I) bridged BODIPY dyad showed a slightly broad and hypsochromically shifted absorption and emission bands compared to BODIPY 2. The electrochemical studies indicated that, the Re(I) bridge BODIPY dyad 1 was easy to reduce compared to BODIPY 2 supporting the electron deficient nature dyad upon Re(I) ion binding. The molecular structure of dyad 1 was further elucidated by DFT computational studies.

Benzimidazole derivative molecules attract attention of scientists due to their bioactivities. The dramatic changes in recorded activities according to the type and position of the substituents motivate synthesis and analysis of new molecules. Commercial benzimidazole-based molecules have been used in therapeutic procedures. It is known that the activities of metal complexes with benzimidazole derivative ligands have different activities when compared to the benzimidazole main structure. Nowadays, one of the most important health problems is COVID-19, which caused the pandemic that we are still experiencing. Although vaccine studies are important to overcome acute problems, regarding the possible post-vaccination adverse effects, the need for new drugs against the virus is obvious. Considering the urgency and the limited facilities during the pandemic, preliminary in silico studies of candidate molecules are essential. In this study, {[bis-(N-benzylbenzimidazole)] tetracarbonylmolybdenum}, {[bis-(N-4-chlorobenzylbenzimidazole)] tetracarbonylmolybdenum} and {[bis-(N-4-methoxybenzylbenzimidazole)] tetracarbonylmolybdenum} were synthesized and characterized. The optimization and the structural analysis of these molecules were performed by DFT/TDDFT methods. The molecules were docked into SARS coronavirus main peptidase (PDB ID: 2gtb), COVID-19 main protease in complex with Z219104216 (PDB ID: 5r82), COVID-19 main protease in complex with an inhibitor N3 (PDB ID: 6lu7) and Papain-like protease of SARS-CoV-2 (PDB ID: 6w9c) crystal structures for evaluation of their anti-viral activity.