SYNTHESIS AND CHARACTERISATION OF NI(II) COMPLEX OF L-LEUCINE

Abstract

Synthesis of [NiL2 ].2H2O (L = L-leucine) was carried out in basic solution and the complex was analysed using gravimetric analysis, molar conductivity measurements, UV-Visible and IR spectroscopies. Molar conductivity measurements showed that the composition of the metal complex corresponds to a metal-amino acid ligand ratio of 1:2. The IR spectrum showed that L-leucine functions as bidentate ligand with coordination involving the carboxyl oxygen and the nitrogen of the amino group. The result also suggests the presence of water of crystallization in the complex. Electronic spectrum and magnetic susceptibility measurements suggested a four-coordinate local symmetry around Ni (tetrahedral) ions. The results also intimate that the ligand, L-leucine, is a weak field ligand as it formed high spin complex with Ni(II) ions. Metal content and hydration water analyses showed that the complex of Ni contains two moles of water of crystallization. The results also hinted that the Ni(II) complex has no aqua ligand in their inner coordination sphere.