Abstract:
Transition metal complexes have played a significant role in the enormous growth of the field of
catalyst. Schiff bases ligands are able to stabilize many different metal ion(s) in various oxidation
states, controlling the performance of metal ion(s) in large varieties of useful catalytic organic
transformations [1]. The Cobalt(II) and Nickel(II) metal complexes of N-benzylideneaniline Schiff
base ligand were synthesized through treatment of the Schiff base ligand with the corresponding
metal halides, normally by heating the Schiff base ligand in the presence of the metal salt under
reflux conditions [2]. The resulting metal complexes were found to be crystalline which have been
characterized using elemental analysis, electrical conductance, magnetic susceptibility
measurements, and spectral techniques like UV-Visible, FT-IR and NMR (
1
H-NMR and
13
C-NMR)
spectrophotometer. The complexes were air-stable, with high melting points and soluble in
methanol and some other organic solvents such as n-hexane, diethylether and DMSO. The molar
conductance of 1x10
-3
M solutions of the metal complexes in methanol at 27
0
C indicates that the
complexes behave as electrolytes. Both Cobalt(II) and nickel(II) metal complexes of N-benzylideneaniline ligand shows paramagnetic nature. The electronic spectra along with magnetic
data suggest square planer geometry for Co(II) and Ni(II) complexes. The FT-IR spectra
determined the υ(C=N) stretching vibration found in the free ligand at 1627 cm
-1
. This band was
shifted to the lower frequencies (1603.5 cm
-1
) in the spectra of the metal complexes verify,
participation of the azomethine nitrogen in the coordination of the metal ions. Finally, the metal
complexes were screened for their catalytic activity via phenol benzoylation reaction and found to
be moderately active.
