Synthesis, physical characterization, antibacterial activity and thermodynamic studies of five coodrdinate cobalt(III) Schiff base complexes

Abstract

ABSTRACT. Some five-coordinated cobalt(III) complexes were synthesized and characterized using elemental analysis, 1 H NMR and IR spectra. The formation constants and the thermodynamic parameters were measured spectrophotometrically for the 1:1 adduct formation of [Co(Chel)(PBu3)]ClO4.H2O where Chel = cd3OMesalen, cd4OMesalen, cd5OMesalen: methyl-2-{[1-methyl-2-(2-hydroxy-3-, 4-, 5-methoxyphenyl)methylidynenitrilo]ethyl}amino-1-cyclopentene-dithiocarboxylate, as acceptors, with some linear and cyclic amines as donors, in different solvents at constant ionic strength (I = 0.1 M NaClO4), and at various temperatures (T = 283-313 K). The results revealed that the formation constants of the Co(III) Schiff base complexes toward a given amines donor are as follow:The trend of the formation constants of the donors (amines) toward a given cobalt(III) complex is as follow: Im > 4-MeIm > BzIm and n-butylamine > sec-butylamine > tert-butylamine. Also the effect of the solvents on the formation constants of a given cobalt(III) Schiff base complex toward a given donor are as follow: CH3CN > DMF > EtOH. The ligands and their cobalt complexes have been screened for their antibacterial activities. All the free Schiff base ligands exhibit higher antibacterial activity than the cobalt(III) complexes.

A microporous metal–organic framework with open metal sites for selective sensing Fe3+, CrO42- and nitrobenzene

“…The phase purity of bulky samples was checked by powder X-ray diffraction (PXRD). For compound 1, the measured PXRD patterns closely match the simulated ones generated from the single crystal X-ray diffraction data (Figure 1c), indicating the pure phase of the products [15]. Based on the its structural feature [21], fluorescence detection experiments were carried out with the DMF suspension of 1, which was carefully explored for sensing metal ions, anions and small organic molecules.…”

“…Moreover, 1 has five potential sensing sites and its sensing properties were not explored at all. Our group has also reported several interesting solventinduced MOFs in recent works [15][16][17][18][19], and the results indicate that sensing feature are mainly controlled by solvent size and polarity, however, the mechanisms of solvent effects are still largely unexplored. Consequently, much research work in this area remains to be done [20].…”

Synthesis of Schiff bases derived from 2-hydroxy-1- naphth- aldehyde and their tin(II) complexes for antimicribial and antioxidant activities

“…These Schiff bases are extensively utilized as drugs which are biological active compounds due this reason it is widely used for industries [1,2]. Schiff bases are important due to carbon nitrogen double bond (C=N) which can coordinate with metal [3].…”

Synthesis, Characterization, X-Ray Crystal Structures and Antibacterial Activity of Cobalt(III) Complexes Derived from 5-Bromo-2-((2-(phenylamino) ethylimino)methyl)phenol

“…5 The coordination chemistry of cobalt is of considerable interest since cobalt(II) and cobalt(III) complexes derived Schiff bases are reported to be biologically active. 6 In addition, the Schiff bases synthesized from salicylaldehyde derivatives with halo atoms in the aromatic ring, showed effective antibacterial activities. 7…”