Experimental and Computational Studies on Heteroaromatic Diimines

Tetradentate Schiff bases (diimines); 14-bis[3-(thiophene-2-carboxaldimine)propyl]piperazine (L1) and 14-bis[3-(furan-2-carboxaldimine)propyl]piperazine (L2) have been synthesized by the reaction of diamines with thiophene/furan aldehydes. The structure of heteroaromatic diimines have been determined by elemental analysis and spectroscopic methods (1H-NMR 13C-NMR UV-vis FT-IR and LC-MS). 1H and 13C shielding tensors for L1 (furbap) and L2(tkbap) were calculated with GIAO/DFT/B3LYP/6-311++G(d p) methods in CDCl3. The vibrational band assignments frontier molecular orbital energies (FMOs) nonlinear optical (NLO) activity reactivity descriptors molecular electrostatic potential surfaces (MEPs) and Mulliken atomic charges were studied at B3LYP/6-311++G(d p) level of theory. Diimine copper(II) complexes have been synthesized and structurally characterized by using UV-vis FT-IR and LC-MS spectra magnetic susceptibility and molar conductivity measurements. Schiff bases and Cu(II) complexes have been screened for their biological activities by microdilution technique (MIC values in mM) using DMSO as solvent on different species of pathogenic bacteri