Synthesis and antibacterial study of Schiff bases from 2,9-phenathroline-1,10-dialdehyde and dithiocarbazates.

摘要

Schiff bases bearing bidentate N,N chelating agents such as 1, 10-phenanthroline (phen) have been used extensively as a ligand in both analytical and preparative coordination chemistry. Metal complexes derived from 1,10- Phenanthroline have interesting physico-chemical properties and also have been found to be widely used in areas such as molecular catalysis, solar energy conversion, calorimetric analysis, herbicides, molecular recognition, self-assembly, antineoplastic agents, and nucleic acid probes. Schiff bases have also been evaluated as antimalarial, anticancer, antibacterial, antifungal, antitubercular, anti-inflammatory, antimicrobial and antiviral.;Four new Schiff bases of 1,10-phenanthroline-2,9-dicarboxaldehyde with sulfur-containing amines such as 2-mercap- toaniline, S-alkyl/aryl dithiocarbazates and thiosemicarbazide have been synthesized and characterized by spectroscopic and X-ray crystallographic techniques. A comparative study of the methods of synthesis has been made using both traditional and microwave techniques. A significant reduction in reaction time has been observed when the microwave method was used. In some of the reactions, the yields also increased significantly. We first prepared an interesting dimeric copper (Cu) complex by using one of these Schiff base.;Four new Schiff bases and their parent aldehyde were used for antibacterial study. The activity of the synthesized compounds was preliminarily evaluated by paper disc diffusion technique. The minimum inhibitory concentrations (MIC) of the compounds were also determined by tube dilution method. All the compounds showed antibacterial activity at the tested dose against different strains of Gram positive and Gram negative bacteria but were considerably less when compared to the reference standard drug tetracycline.