pH-metric and theoretical studies of the complexation of 2-[α-(o-hydroxyphenyl) ethylidenehydrazino]-4,6-dimethylquinoline and 2-[α-(o-methoxyphenyl)methylidenehydrazino]-4,6-dimethylquinoline

Abstract

2-[α-(o-Hydroxyphenyl)ethylidenehydrazino]-4,6-dimethylquinoline (AHQ) and 2-[α-(omethoxyphenyl)methylidenehydrazino]-4,6-dimethylquinoline (BHQ) have been synthesized and characterization is performed by elemental analysis and electronic, vibrational and mass spectra. The pK H and log K were gritty in 75% solvent-water pH-metrically for BHQ ligand and at various temperatures for AHQ ligand. The dissociation and stability constants in the aqueous medium for BHQ ligand have been calculated by the relation of pK H or log K with solvent parameters (D, ET, AN and DN). The isokinetic temperature was determined by using a linear regression analysis (LRA) of ΔΗ° vs. ΔS° for AHQ complexes. The thermodynamic parameters of AHQ compounds were analyzed into their electrostatic (el) and non-electrostatic (non) or cratic components. Full geometrical and structural optimizations of the ligands have been performed by a DFT study by using the hyperchem program.

New solvatochromic complexes of 1,2‐bis[(5,6‐diphenyl‐1,2,4‐triazin3‐yl)hydrazinylidene‐methyl]benzene: Synthesis, spectroscopic, biological, docking, and theoretical studies

“…Table 2 collects the main IR bands with their tentative assignments; the stretching vibrations appeared in the range of 3375–3430 cm −1 may be assigned to NH and/or OH groups. [ 51–57 ] The ν(C=N)azomethine of the ligand (H 2 BDTB) observed at 1588 cm −1 exhibits a shift to a lower frequency in the range of 1562–1582 cm −1 in complexes. [ 30,31 ] Additionally, ν(C=N)triazine of the H 2 BDTB observed at 1521 cm −1 shifted in complexes to the range 1497–1516 cm −1 , suggesting allocation of C=N azomethine and C=N triazine as coordination centers.…”

“…OH groups. [51][52][53][54][55][56][57] The ν(C=N)azomethine of the ligand (H 2 BDTB) observed at 1588 cm À1 exhibits a shift to a lower frequency in the range of 1562-1582 cm À1 in complexes. [30,31] Additionally, ν(C=N)triazine of the H 2 BDTB observed at 1521 cm À1 shifted in complexes to the range 1497-1516 cm À1 , suggesting allocation of C=N azomethine and C=N triazine as coordination centers.…”

Co (II), Ni (II), and Cu (II) complexes of 4,6‐bis(2‐hydroxynaphthalen‐1‐yl)methyl‐ene)hydrazono)ethyl)benzene‐1,3‐diol: Synthesis, spectroscopic, biological, and theoretical studies

“…[3] In addition, they are utilized as herbicides, insecticides, and plant growth controllers [4,5] as well as catalytic, analytical, and biological applications. [6,7] The biological applications are given by hydrazones, and their metal complexes comprise antifungal, anticonvulsant, antibacterial, antioxidant, antimalarial, analgesic, anticancer, anti-inflammatory, antiviral, and antituberculosis activities. [8][9][10][11][12][13][14] The coordinating behavior of the di-carbonyl compound 4,6-diacetylresorcinol (2,4-dihydroxy-5-acetylacetophenone) (DAR) has been studied.…”

Binuclear Co(II), Ni(II) and Cu(II) Complexes of a new Bis(tridentate) Hydrazone Ligand: Synthesis, Thermal, Spectroscopic, Biological, Molecular Docking and Theoretical Studies

“…Hydrazones have attracted a great and continuous interest, due to their simple synthetic methods, easy complexation with different metal ions as well as their diverse applications. Hydrazones and their complexes have many biological, catalytic and analytical applications [1][2][3]. The biological activity of these compounds includes antifungal, anticonvulsant, antibacterial, antimalarial, analgesic, antimicrobial, anticancer, anti-inflammatory, antiviral and antituberculosis activities [1,[4][5][6][7][8][9][10].…”