Binuclear cobalt(II), nickel(II), copper(II) and palladium(II) complexes of a new Schiff-base as ligand: Synthesis, structural characterization, and antibacterial activity

Synthesis, spectroscopic studies and inhibitory activity against bactria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand

“…This band was shifted towards lower frequencies compared to the ligand spectrum indicating the coordination of amino nitrogen to the metal ion [29] . On the other hand, the NH group presets at the same position for the acyclic complexes of Co(II) and Zn(II) and VO(IV) in addition to all dinuclear macrocyclic complexes, suggesting the non-involvement through the coordination sphere of the complexes, similar behavior have been observed [30].…”

Template synthesis, spectroscopic studies, antimicrobial, nematicidal and pesticidal activities of chromium(III) macrocyclic complexes

“…This may be explained by Tweedy's Chelation theory 33 according to which chelation reduces the polarity of the central metal atom because of the partial sharing of its positive charge with the ligand, 34 which favours permeation of the complexes through the lipid layer of cell membrane. 35 Other factors such as solubility, conductivity and dipole moment, which are affected by the presence of metal ions may also be possible reasons for increasing the biological activity of the metal complexes as compared to the corresponding ligands.…”

Synthesis, spectral characterization, antimicrobial, DNA binding and antioxidant studies of Co(II), Ni(II), Cu(II) and Zn(II) metal complexes of novel thiosalen analog N2S2

“…The g|| > g > 2.0023 indicates that the unpaired electron is present in the dx2-y2 ground state in a square planar geometry [47]. Moreover, g|| < 2.3 value suggests covalent character of the metal-ligand bond [48]. This is further supported by calculating the axial symmetry parameter (G), which is a measure of exchange coupling interaction between two Cu(II) ions using Kneubuhl's method [49], G = (g‖-2.0023)/(g-2.0023).…”