Synthesis, photophysical properties, and antimicrobial activity of novel styryl colorants derived from 7-methoxy-1,4-diphenethyl-1,2,3,4- tetrahydroquinoxaline-6-carbaldehyde

摘要

The novel 1,4-diphenethyl-1,2,3,4-tetrahydro-7-methoxyquinoxalin-6- carbaldehyde was synthesized by reductive alkylation of 6-methoxy quinoxaline with phenyl acetic acid and was further subjected to Knoevenagel condensation with various active methylene compounds to synthesize novel styryl colorants. Photophysical properties of styryl colorants were studied using UV-visible and fluorescence spectroscopy. These colorants displayed orange to violet hue and showed fluorescence emission maxima in the region of 560-640 nm, and displayed a large Stokes shift (85-104 nm). Compounds were subjected to thermogravimetric analysis which showed excellent stability up to 310°C. These styryl compounds were evaluated for their antimicrobial study as antifungal against Candida albicans C. albicans and Aspergillus niger and antibacterial against Escherichia coli and Staphylococcus aureus. The results revealed good antimicrobial activity against tested organisms. The synthesized chromophores were characterized using elemental analysis, FTIR, ~(13)C-NMR and ~1H-NMR spectroscopy and mass spectrometry.