Coordination complexes constructed from pyrazole–acetamide and pyrazole–quinoxaline: effect of hydrogen bonding on the self-assembly process and antibacterial activity

Abstract

Two mononuclear coordination complexes of N-(2-aminophenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (L1) and one mononuclear complex, obtained after in situ oxidation of L1, have been synthesized and characterized spectroscopically.

CuII Pyrazolyl‐Benzimidazole Dinuclear Complexes with Remarkable Antioxidant Activity

“…In the reaction condition (presence of FeCl 2 ⋅ 4 H 2 O), ligand L undergoes an oxidation reaction by the oxygen in the air involving the methylene group linked to pyrazolic and benzimidazolic moieties. A plausible mechanism of this interesting oxidation reaction has been proposed on the basis of the oxidation of enaminic compound under the action of the oxygen in the air as shown in a previous works [39,40] . The ligand used can exist under two iminic and enaminic tautomeric forms L and L 1 .…”

“…A plausible mechanism of this interesting oxidation reaction has been proposed on the basis of the oxidation of enaminic compound under the action of the oxygen in the air as shown in a previous works. [39,40] The ligand used can exist under two iminic and enaminic tautomeric forms L and L 1 . Thus, the enaminic tautomer L 1 undergoes an oxidation reaction by the oxygen in the air to afford the spiro dioxetane [A] which undergoes a ring opening of the dioxetane moiety leading to the unstable intermediate [B] which aromatized after the loss of a water molecule to furnish the ligand L'.…”

“…In particular, Cu II complexes tethered with heterocyclic moieties have received much interest as antioxidant agents. [7,9,[33][34][35][36] Continuing research along this line, [37][38][39][40] we have designed a new benzimidazole derivative functionalized with a pyrazole unit leading to L, namely 1-n-butyl-2-((5-methyl-1H-pyrazole-3yl) methyl)-1H-benzimidazole (Scheme 1), by applying a recently conceived design approach. [37] A complexation reaction of L and Fe II chloride followed by addition of Cu(NO 3 ) 2 • 3 H 2 O led to an oxidation reaction involving the methylene group linking the benzimidazole and pyrazole moieties in L to form the ligand L' (Scheme 1).…”

Crystal structure and Hirshfeld surface analysis of ethyl 2-(7-chloro-3-methyl-2-oxo-1,2-dihydroquinoxalin-1-yl)acetate

“…Nitrogen-based structures have attracted more attention in recent years because of their interesting properties in structural and inorganic chemistry (Faraj et al, 2022;Chkirate et al, 2022aChkirate et al, ,b, 2023Al Ati et al, 2024). The family of quinoxalines, particularly those containing the 2-oxoquinoxaline moiety, is important in medicinal chemistry because of their wide range of pharmacological applications such as antibacterial activity (Chkirate et al, 2022c) and as potential anticancer agents (Abad et al, 2023). In particular, 3-methyl-2-oxoquinoxaline is a cytotoxic (Missioui et al, 2022a) and anticonvulsant agent (Ibrahim et al, 2013) and has anti-COVID-19 and anti-Alzheimer's disease (Missioui et al, 2022b) activities.…”

High Inhibition for a CoII Tetrazole Bi‐pyrazole Dinuclear Complex against Fusarium Oxysporum f. sp. Albedinis

“…[18] Their efficiency has been well documented in oncology, [19,20] and neurodegenerative diseases, [21] due to their greater variety of geometries and a higher tridimensionality than most organic compounds. [22] Up to now, a wide range of Cu II , Co II and Cd II complexes with azole based donor ligands have shown remarkable antifungal and antibacterial activities, [23][24][25] together with a low toxicity. [9] A vascular disease caused by the fungal infection of Fusarium oxysporum f. sp.…”