Synthesis, thermal behaviour and some properties of CuII complexes with N,O-donor Schiff bases

Abstract

The complexes of N 2 O 2 -, N 2 O 3 -and N 2 O 5 -donors Schiff bases with Cu II ions in the methanol solution have been synthesized. They were characterized by elemental analysis, X-ray crystallographic techniques, spectroscopic (UV-Vis, IR) and thermal (TG, TG-FTIR) methods. The catalytic activity of the prepared complexes for the hydrogen peroxide-assisted degradation of methylene blue (MB) as the model compound in water was also investigated. The complexes were obtained as crystalline solids. Depending on the Schiff bases and the molar ratio of Cu II :ligand used in the synthesis, they can form monomeric or dimeric structures. The coordination environment around the metal centre in both solution and solid states is a slightly distorted square-planar. The values of magnetic moments determined at room temperature show the existence of antiferromagnetic interactions. The complexes are stable at ambient temperature. After heating, at first solvates lose solvent molecules; after that, an organic part undergoes gradual defragmentation and combustion. Degradation efficiency of MB in the presence of complexes was found to be 68.18-97.47%. A tentative mechanism involving HOÁ radical as an oxidant for degradation of MB was proposed.

Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules

“…The FTIR spectra of dry microcapsule formulations prepared with or without Cu(II) complex, and of single constituents, Cu(II) complex, sodium alginate, chitosan, and calcium chloride are presented in Figure 1 . The most characteristic bands of the Cu(II) complex are in correlation with the literature data of similar copper compounds [ 21 , 22 , 23 ]. Characteristics of Cu(II) complex spectra are peaks at 3433 cm −1 corresponding to the stretching vibration of -OH groups, at 1740 cm −1 to COO - and 1266 cm −1 to CH 2 stretching vibrations.…”

Synthesis, Structural and Thermal Studies of 3-(1-Benzyl-1,2,3,6-tetrahydropyridin-4-yl)-5-ethoxy-1H-indole (D2AAK1_3) as Dopamine D2 Receptor Ligand

“…Further heating breaks a bond between the benzyl group and the tetrahydropyridine unit. This is confirmed by several bands appearing in the 3200–2800 cm −1 range (with four maxima at 3072, 3032, 2933 and 2885 cm −1 ) and 800–600 cm −1 (with the maxima at 728 and 692 cm −1 ), which can be assigned to the toluene molecule [ 35 , 36 ].…”

“…Similar to analysis conducted in oxidizing atmosphere, at the beginning of the thermal decomposition (about 240 °C) under nitrogen stream in the FTIR spectra of evolved gaseous products, the bands characteristic of H 2 O, CO 2 and toluene molecules are observed. With the increasing temperature, the intensity of the bands associated with the vibration of C 6 H 5 CH 3 increases and also appears characteristic of the NH 3 double peak (965 and 930 cm −1 ) [ 35 , 36 , 37 ] further indicating a partial degradation of substituent on the pyrrole ring. Around 352 °C in the FTIR spectra of volatile pyrolysis products other fragments of the compound appear, probably in the form of indole and piperidine molecules (see Figure 11 ).…”

Chiral crystallization of a zinc(II) complex

“…Schiff bases and their coordination compounds play an important role in metal coordination chemistry owing to their thermal stability, relevant biological properties and high synthesis flexibility (Bartyzel, 2018;Siddiqui et al, 2006;Sacconi, 1966). These ligands are able to coordinate a wide variety of metal ions and to stabilize them in various oxidation states.…”