Synthesis, Staructure and Redox Properties of Cu(II) Chelate Complexes on the Basis of 2‐(Hydroxyphenyl)‐1H‐benzo[d]imidazol‐1‐yl Phenol Ligands

Abstract

A series of 2-(hydroxyphenyl)-1H-benzo [d]imidazols bearing readily oxidizable 2,6-di-tert-butyl-phenol substituents and bischelate Cu(II) complexes based on these ligands were synthesized. The structure of the compounds was characterized by NMR, IR, mass spectroscopy and X-ray crystallographic analysis and redox behavior explored using ESR spectra and cyclic voltammetry. Under oxidation with PbO 2 in toluene solution both the ligands and Cu(II) complexes form stable phenoxyltype radicals. As shown by ESR measurements and DFT calculations, no exchange interaction exists between unpaired electrons located on metal and oxygen centers in the biradical Cu (II) complexes. The ligands and complexes reveal antioxidant radical scavenging activity measured spectrophotometrically and using ESR and DPPH-tests.

Heavy Metals Treated Soil Effects on the Concentration of Chlorophyll A, B, and Mineral Elements in Algae

“…These results were consistent with the previous findings showing a significant decrease in chlorophyll b and carotenoid content with a high cadmium concentration in Chlorella vulgaris (Cheng et al, 2017). The absorption of heavy metals and their distribution inside the plants and their impact on plants depend on the vegetable type, the duration of exposure to the heavy metals, and the metal concentration during growth (Ivakhnenko et al, 2021), and may also be due to the low magnesium concentration (AL-Rashedy and AL-Hamadany, 2021). The accumulation of cadmium inside the plant works to reduce the size of the cells, the rate of distribution of gaps in the skin, and low cell division, in addition to its effect on green plastids (Abbas et al, 2017).…”

Intramolecular Cyclization of the ortho‐Substituted N‐arylquinone Imines under Basic and Thermal Conditions

“…The structure of benzimidazole 13 was confirmed by X-ray diffraction analysis (Figure 2). In contradistinction to the almost coplanar arrangement of the benzimidazole and 2-aryl substituent in the previously described close structural analog of benzimidazole 13, [15] the interplanar angle formed bythe imidazole ring and the p-nitrophenyl fragment is 21.01°. At the same time, the twisting of 3,5-di-tert-butyl-4-hydroxyphenyl fragments is almost identical; the C15À C14À N2À C2 torsion angle is 58.86°(in contrast 58.45°).…”

Effect of Cadmium and Copper Exposure on Growth, Physio-Chemicals and Medicinal Properties of Cajanus cajan L. (Pigeon Pea)

“…Metal uptake and distribution in a plant depends on the species, the metal concentration in the growth medium, and the plant's exposure to metal stress [26,27]. In our results (Figure 5), pigeon pea roots retained higher Cd and Cu content compared to leaves.…”

“…Oxidative stresses disturb cellular redox balance and damage delicate cellular entities such as DNA molecules, proteins, and membranes [25,26]. To minimize metals induce damages, plants have evolved different strategies including metal exclusion; compartmentalization; chelation; and a wide spectrum of ROS-scavenging mechanisms, including antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione reductase (GR), ascorbate peroxidase (APX), as well as non-enzymatic antioxidants including phenolics, flavonoids, proline, ascorbate (AsA), glutathione (GSH), along with an array of stress mitigation molecules [27][28][29][30][31]. Plants' secondary metabolites not only perform their role in plant adaptation to the specific environment, but also are an important source for pharmaceuticalrelated drugs [30].…”