Synthesis and spectroscopic determination of Cu(II) and Co(II) metal complexes with pthalamide and 2,4-dinitrophenylhydrazine

Abstract

Copper (II) and Cobalt (II) metal complexes were derived from the synthesis of pthalamide and 2,4-dinitrophenylhydrazine. Both synthesized metal complexes were found to be soluble in acetone and butanol, slightly soluble in n-hexane and propan-1-ol, partially soluble in ethanol and methanol, and insoluble in water. The synthesized Cu (II) and Co (II) metal complexes were characterized by IR, Uv-Vis, TGA, XRD and Magnetic Susceptibility. The IR spectral bands observed for both Cu (II) and Co (II) metal complexes are3287.5cm-1 (N-H) stretch, 708.19 cm-1 (N-M) stretch, 1729.5cm-1 (C=O) stretch, 1610.20cm-1 (C=C) stretch, 1043.65cm-1 (N-N) stretch and 3101.1cm-1 (C-H) ar-stretch, 1334cm-1 (NO2) stretch for Cu (II) complex while 3145.9cm-1 (C-H) ar-stretch, 1341cm-1 (NO2) stretch for Cu (II) complex. The electronic transitions found from the Cu-Complex were 236.95nm (n- π*) assigned to C=O, 207.29nm (π- π*) assigned to C=C, 400.82nm (n- π*) assigned to NO2 and a band of 472nm assigned to the LMCT. The Co-Complex also has bands at 237.8nm (n-π*) assigned to C=O, 215.58nm (π- π*) assigned to C=C, 401.82nm (n- π*) assigned to NO2 and 465nm assigned to the LMCT. The decomposition of the synthesized complexes were to be 205oC and 202oC for Cu-Complex and Co-Complex respectively. The thermal decomposition of the complexes were also observed by TGA. The XRD results showed that the Cu-Complex is crystalline while the Co-Complex is amorphous and the Magnetic Susceptibility of the complexes was also confirmed for their paramagnetic nature.