Schiff Base Ligand Research Paper

DNA binding, Photo cleavage, Docking, cytotoxic and antimicrobial activity of novel Schiff base ligand and its metal complexes
B.Kavitha and P.Saritha Reddy*
Department of chemistry, Osmania university, Hyderabad 500 007, Telangana, India

Abstract : A new bidentate ON type of Schiff base ligand derived from 2-amino benzyl alcohol with 2-hydroxy-3-methoxy benzaldehyde and its bi and trivalent metal (Cu(II), Co(II),Cr(III),Zn(II)) complexes has been synthesized. The synthesized ligand and metal complexes were characterized by analytical, spectral (FT-IR, 1H-NMR, LCMS,TGA/DTA,EPR,UV-visible, single crystal XRD) , conductivity, magnetic and docking studies . Based on the analytical , spectral and dockind studies square planar and octahedral

Arulmurugan et al[15] by the condensation of 10ml of 2-amino benzyl alcohol (0.02g, 5mmol) with vanillin (0.011g, 5mmol) in ethanol (1:1 molar ratio). The mixture was then refluxed for 3h and the progress of the reaction was monitored by TLC. The product obtained was filtered, washed in distilled water, dried, and preserved in a desiccator containing CaCl2.

2.3. Preparation of the Schiff base metal (II) complexes : An ethanolic (20 ml) solution of schiff base ligand (40mmol, 0.11g ) was added drop wise to 20ml of the metal(II) salts [20mmol, 0.04g of CuCl2.4H2O, 0.048g of CoCl2.6H2O, 0.048g of CrCl3.6H2O, and 0.044g of ZnCl2.2H2O] in boiling ethanol(78.70C). The reactions took place in 2:1 mole ratio of HL: metal (II). The reaction mixture was refluxed for 4-6hrs on a water bath and the volume of the solution was reduced to half of the initial volume. The product obtained was filtered, washed with water, diethyl ether and then dried in a vacuum over CaCl2 [16, 17].
3. Results and Discussion 3.1. Physical Properties and Elemental

The absence of a half field signal at 1600 G corresponding to the DMs = ±2 transition, rules out any Cu-Cu interaction23&24. The g tensor values of the copper complexes can be used to derive the ground state. In square planar complexes, the unpaired electron lies in the dx2_y2 orbital giving 2B1g as the ground state with gll > g^> 2, while the unpaired electron lies in the dz2 orbital giving 2A1g as the ground state with g^ > g ll > 2. From the observed values, it is clear that All > A^ and gll > g^> 2 which suggest that all the complexes are square planar geometry and the system is axially symmetric25. Furthermore, this conclusion is also supported by the fact that the unpaired electron lies predominantly in the dx2_y2 orbital, which was evident from the value of the term G = 5.3 – 4.5. It also suggests that the local tetragonal axes are aligned parallel or slightly misaligned. The ESR parameters and d-d transition energies were used to evaluate the bonding parameters a2, b2 and g2 for the Cu(II) ion in various ligand field environments which may be regarded as measures of the covalence of the in-plane s-bonds (α2), in-plane p-bonds (b2) and outof-plane p-bonds (g2) respectively26&27. The observed values of a2 indicate that complexes have some covalent character while theb2 and g2 values indicate that there is