Synthesis, characterisation and antimicrobial studies of mixed nickel (II) and copper (II) complexes of aroylhydrazones with 2, 2¹ - bipyridine and 1, 10-phenanthroline

Synthesis, Characterisation and Acetylcholinesterase Inhibition Activity of Nickel(II) and Copper(II) Complexes of <i>3</i>-Hydroxybenzaldehyde-<i>4</i>-nitrobenzoic Acid Hydrazone

“…The room temperature magnetic moment for the nickel(II) complex is 2.92 B.M and this showed that the complex is paramagnetic with two unpaired electrons, suggesting an octahedral geometry for the complex [25]. Cu(II) complex had a moment of 1.65 B.M which is lower than the spin only value of 1.73.B.M.…”

“…These shifts are indicative of interaction between the ligands and the metal ions. The metal-oxygen and metal-nitrogen bonds [13,17,25] which hitherto were absent in the free ligand appeared in the nickel(II) complexes at: 692 cm -1 (M-O) and 559 cm -1 (M-N), and in copper(II) complex at 689 cm -1 (M-O) and 572 cm -1 (M-N). The ν(H-O) band appeared in the free ligand at 3472 cm -1 .…”

“…The ligand (L), had a band of weak intensity at 3280 cm -1 due to ν(N-H) vibrations. This band had a bathochromic shift to lower energy at 3208 cm -1 in the Ni(II) complex and to 3210 cm -1 in Cu(II) complex [25,28]. The ν(C=O) band appeared at 1664 cm -1 in the free ligand.…”

“…Acetylcholinesterase inhibitors with antioxidant activities are considered as having potentials for treatments of Alzheimer disease and the last decades have seen increasingly rapid advances in the field of developing acetylcholinesterase inhibitors [8,9]. Hydrazones have interesting biological activities and have attracted great attention in the last decades [25,26)]. There are reports that hydrazone compounds show profound acetylcholinesterase inhibition activities [10][11][12].…”

Untitled

“…The metal ion (Fe ++ ) is Lewis acid, while the ligands are Lewis base due to the presence of nitrogen atoms in the ring that contains electron pairs. These atoms are responsible for the appearance of the physical and chemical properties of the resulting complex [17][18][19]. The presence of heterogeneous aromatic ligands in the donor structure gives the bonds additional properties, such as the poly-nitrogen donor, which increases the binding capacity of the ion with the physical properties of the ligand.…”