Synthesis, Structural Characterization and Biological Activity of Novel Cyclohexane-1,3-dione Ligands and Their Metal Complexes

Abstract

Some new Zn(II) and Cu(II) complexes [Cu(LC-NMR and ultraviolet (UV-Vis.) spectroscopy, elemental analysis, magnetic susceptibility, mass spectrometry and thermogravimetrydifferential thermal analysis (TGA-DTA). The synthesized ligands and their complexes were tested for antibacterial activity against Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Salmonella typhimurium CCM 583. Some of complexes showed medium-level antibacterial activity against the test bacteria compared with ampicillin.

Synthesis and structural characterization of oxovanadium(IV) complexes of dimedone derivatives

“…The preparation procedure of the ligands (HL n ) was described in details by Japp-Klingemann reaction [17,18] between the diazonium salt of aniline derivatives (0.01 mol) and dimedione (1.40 g, 0.01 mol). The solid azo dyes represented in Figure 1, were collected by filtration, washed with water and dried in oven at 80 C. Finally, the compounds were recrystallized from methanol to give colored crystals (HL n ).…”

“…This band is disappeared in the VO (IV) complexes, which demonstrating that the ligands are coordinated in the deprotonated hydrazone form. [18,28] 2 At 1677-1674 cm −1 region, the band of ν(C=O free) of the ligands is shifted to the lower wavenumber by 9-14 cm −1 indicating their coordination to the V-center. Moreover, the band of ν(C=O … H) group which appear in the ligand spectra at 1618-1624 cm −1 region, indicates that the studied ligands are stabilized in the hydrazo form with formation of a hydrogen bond between the hydrazone = N − NH− moiety and a carbonyl group giving a six membered ring.…”

Mn2+-COMPLEXES OF N,O-DIHYDRAZONE: STRUCTURAL STUDIES, INDIRECT BAND GAP ENERGY AND CORROSION INHIBITION ON ALUMINUM IN ACIDIC MEDIUM

“…It is suggested that the manganese raises mobilization of the ligand electrons by accepting them in its shell thus the width of the localized levels in the resulting complex is expanded and in turn, the band gap is smaller. This result has many applications in optics, electronics and energy conversion devices [48]. In fact small band gap facilitates electronic transitions between the HOMO-LUMO energy levels and makes the molecule more electro-conductive [49].…”

Preparation, Characterization and Biological Activity of New Tridentate Imine-Oxime Ligand (H2L) and Its Metal Complexes

“…The first three absorption peaks assigned to π→π * transitions of benzene rings and oxime azomethine group [17,18], the fourth absorption peak assigned to π→π * transition of Schiff azomethine group [17,19]. The fifth low intensity absorption peak assigned to intra-ligand charge transfer transitions (ILCT) [20]. Spectrum of Cr 3+ (C1) complex, exhibits three absorption peaks [21] at (669 nm, 14947 cm -1 ), (559 nm, 17889 cm -1 ) and (435 nm, 22988 cm -1 ).…”

“…Spectrum of Cr 3+ (C1) complex, exhibits three absorption peaks [21] at (669 nm, 14947 cm -1 ), (559 nm, 17889 cm -1 ) and (435 nm, 22988 cm -1 ). First two them assigned to ( 4 A2g (F) → 4 T2g (F) ) (ν1) (10Dq) [20] and ( 4 A2g (F) → 4 T1g (F) ) (ν2) [21], transitions, respectively. The third peak assigned to ( 4 A2g (F) → 4 T1g (P) ) (ν3) and charge transfer (CT) transitions.…”