Two mono‐ and dinuclear Cu (II) complexes derived from 3‐ethoxy salicylaldehyde: X‐ray structures, spectroscopic, electrochemical, antibacterial activities, Hirshfeld surfaces analyses, and time‐dependent density functional theory studies

Abstract

The quinazoline-type ligand 2-(3-ethoxy-2-hydroxyphenyl)-4-methyl-1,-2-dihydroquinazolin 3-oxide (HL 1 , H is the deprotonatable hydrogen) was synthesized. Two mono-and dinuclear Cu (II) complexes, [Cu(L 2 ) 2 ]Á2CH 3 OH (1),amino}phenyl)ethanone oxime), were obtained via complexation of HL 1 with Cu (II) acetate monohydrate or Cu (II) nitrate trihydrate in methanol. HL 1 and both complexes were characterized by elemental analyses and spectroscopic methods. The structures of complexes were confirmed by single-crystal X-ray crystallography and the ratio of ligand to metal in 1 was 2:1 whereas 2 was 1:1. In the crystal structures, hexa-coordinated Cu (II) complex 1 was assembled into an infinite 1-D, 2-D network and 3-D supramolecular framework. Complex 2 included four deprotonated (L 2 ) À units, four coordinated Cu (II) and two coordinated nitrate anions, forming an infinite 2-D layer and interesting butterfly-shaped 3-D supramolecular skeleton. Specifically, the Cu1 and Cu4 centers were four-coordinated, while the Cu2 and Cu3 centers were penta-coordinated in 2. Furthermore, electrochemical properties and antibacterial activities of both complexes were also investigated. In addition, the electron paramagnetic resonance (EPR) spectra of 1 and 2 were also studied. The optimal geometries, HOMO-LUMO energies and molecular electrostatic potential diagrams of two complexes were calculated using density functional theory (DFT)/B3LYP, and specific electronic transitions in the UVvis spectra of 1 and 2 were recorded by time-dependent DFT (TD-DFT) calculations. Additionally, the noncovalent interactions between both complexes were also confirmed by Hirshfeld surfaces.

A new 1D Mn(II) coordination polymer: Synthesis, crystal structure, hirshfeld surface analysis and molecular docking studies

“…The main purpose of this analysis was to emphasize the specific characteristics of the mapped HSA and HSA dormitories. Quantitatively, various interactions and their contribution to HSA were investigated [ 85 , 86 ]. Hirshfeld surfaces illustrated in Fig.…”

Ratiometric Electrochemical Sensor for Butralin Determination Using a Quinazoline-Engineered Prussian Blue Analogue

“…The quinazoline ring is formed by the union of a benzene ring with a six-membered ring containing 2 N atoms and contains three main isomers, namely, quinoxaline, cinnoline, and phthalazine [ 5 ]. Quinazoline and its derivatives have multiple biological activities and show a high affinity for metal ions; they also form all kinds of coordination compounds with sundry transition metals [ 7 ]. Regarding the application in electrochemical sensors, introducing nitrogen moieties into the electrode composition has obtained considerable interest, as it leads to the improvement of conductivity and of the electroactive area of the sensor, hence further boosting its electrochemical performance [ 8 ].…”