Potentiometric and antimicrobial studies on the asymmetric Schiff bases and their binuclear Ni(II) and Fe(III) complexes; synthesis and characterization of the complexes

Abstract

The protonation constants of two nitro-Schiff bases SB 1 , SB 2 and three asymmetric tetradentate diimines H 2 L 1 , H 2 L 2 and H 2 L 3 and the stability constants of their ML type binuclear Ni(II) and Fe(III) complexes have been determined potentiometrically. The asymmetric diimines are (2OH) RACH‚NAC 6 H 4 ACH‚NAR 0 (2OH) type compounds [where R = R 0 = phenyl for H 2 L 1 ; R = naphthyl, R 0 = phenyl for H 2 L 2 and R = R 0 = naphthyl for H 2 L 3 ]. The effect of tautomeric forms on the acid-base properties of the diimines has been investigated and discussed. In addition, dimeric and binuclear Ni(II) and Fe(III) complexes of the diimines have been synthesized and characterized by physical and spectroscopic techniques. Also, in vitro antimicrobial activities of the diimines and the complexes have been evaluated against three bacteria: Micrococcus luteus (NRLL B-4375), Bacillus cereus (RSKK 863), Escherichia coli (ATCC 11230) and the fungus: Candida albicans (ATCC 10239). ª 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Synthesis of novel azo linkage-based Schiff bases including anthranilic acid andhexanoic acid moieties: investigation of azo-hydrazone and phenol-ketotautomerism, solvatochromism, and ionochromism

“…Here, n is an integer (1), λ is the wavelength of Cu K α radiation (1.5406 Å), and θ is the Bragg diffraction peak angle. 40 X-ray diffractograms of L 1 and L 2 showed six and nine broad crystalline peaks, respectively, confirming that they have poor crystallinity in phase (Figures 2a and 2b). The average particle size was calculated from the main XRD peak using the Debye-Scherrer formula (Eq.…”

Synthesis, Spectral Characterization, and Biological Activities of Some Metal Complexes Bearing an Unsymmetrical Salen-Type Ligand, (Z)-1-(((2-((E)-(2-Hydroxy-6-methoxybenzylidene)amino)phenyl)amino) methylene) Naphthalen-2(1H)-one

“…Ten the loss of methoxy and two C 4 H 4 is at 375-630 °C, and the loss of the remaining organic group is at 630-870 °C. Finally, the stable compound Fe 2 O 3 could be obtained above 870 °C [44].…”

Potansiyel Antimikrobiyal Ajanlar Olarak Yeni Asimetrik Schiff Bazlarının Sentezi

“…These type of unsymmetric diimines with respect to the unsymmetrical nature of the imine bond were first reported by our group proposing a new two step method [25]. Afterwards, that study was followed by potentiometric, tautomeric and antimicrobial studies of these type of unsymmetric Schiff bases [26][27][28][29][30][31].…”