Abstract

Vijay Kumar¹, Rajiv Kumar Singh², Veena Kumari³, Birendra Kumar⁴ and Shivadhar Sharma³

DOI : http://dx.doi.org/10.13005/ojc/3404030

The ligand, 3-hydroxy-4-methoxybenzaldehydethiosemicarbazone has been prepared by the condensation of 3-hydroxy-4-methoxybenzaldehyde and thiosemicarbazide. With the help of this ligand the complexes of Co(II), Ni(II) and Cu(II) have been prepared with general formula [ML₂X₂] where X is secondary ligand, Cl^–, NO₃^– and CH₃COO^–. The composition of complexes has been established by their microanalysis, while the metal contents have been determined gravimetrically and volumetrically. On the basis of IR spectra, the coordinating mode of ligand has been determined and has been found to have coordinated through azomethine nitrogen and thione sulphur. The magnetic moment of Co(II) complexes has been found between 4.96-4.72 B. M. The value is slightly higher than the μ_s value corresponding to three unpaired electrons (3.872 B.M). The increase in value may be attributed to orbital contribution from ⁴T_1g ground state cubic term. The appearance of four bands in their electronic spectra is indicative of tetragonally distorted octahedral geometry of Co(II) complexes. The magnetic moment (3.20-3.30 B. M.) and appearance of 4 bands in the electronic spectra of Ni(II) complexes confirms the distorted octahedral geometry of the complexes. The magnetic moment of Cu(II) complexes has been determined to be (1.95-2.20 B. M.) which shows that Cu(II) complexes are magnetically dilute complexes. The appearance of three bands in their electronic spectra confirms John - Tellor distortion in octahedral symmetry of Cu(II) complexes. The various crystal field parameters exhibiting tetragonal distortion in the octahedral symmetry have also been derived. The positive value of D_t predicts tetragonal elongation in O_h symmetry.

Oh Symmetry; Tetragonally Distorted; Tetragonal Elongation

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