Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals

•A viable and ecological approach in synthesis.•All the analyses results reveal the actuality of monomeric chelates of bidentate Schiff bases.•The Cd(II) and Sn(II) complexes are diamagnetic at room temperature.•Thermal data suggested that the complexes are more stable than the ligands.•Antimicrobial activity statistics indicates that the complexes are more reactive than Schiff bases.

This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X = O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV–Vis, NMR (1H, 119Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37 °C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively.

Graphical abstractIt has been observed on comparison with standard references compounds to antibiotic and fungicides, the complexes are show good microbial activity than that of ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide