Synthesis and characterization of Mono-Aqua-Pentakis (Isoni-Cotinic Acid) Nickel (II) Sulfate Trihydrate

Abstract

Abstract.A complex of nickel (II) with isonicotinic acid (asint) was successfully obtained. The complex was synthesized in 1:2 mole ratio of metal to the ligand in methanol. The percentage of nickel was 6.91% determined by Atomic Absorption Spectroscopy (AAS). Therefore, the predicted formula was Ni(asint) 5 SO 4 (H 2 O) 4 . The molar conductivity of the complex was measured by conductivity meter corresponding to 1:1 electrolyte. The thermal analysis of the formed complex was determined by Differential Thermal Analysis (DTA) indicating that the complex contains four water molecules as ligand and hydrates. The magnetic susceptibility measurement showed that the complex was paramagnetic with µ eff = 3.30 B.M. Electronic spectra of the formed complex appeared at two transition peaks on λ= 394 nm and 659 nm. The infrared spectra of the complex showed a shift of tertiary N-group absorption in 1234 and 1338 cm -1 compared to isonicotinic acid at 1149 and 1331 cm -1 . In addition, the shift also appeared in the -OH group absorption which was to the lower wavenumber at 3371 cm -1 from 3425 cm -1 (isonicotinic acid). This fact indicated that the functional groups were coordinated to the central metal ion. The possibility formula of the complex was [Ni(asint) 5 (H 2 O)]SO 4 ·3H 2 O with octahedral structure.