Synthesis, characterization, and antimicrobial activities of novel double-armed benzo-15-crown-5 and their sodium and potassium complexes

New aldehyde- and halogen- (Cl, Br, I) substituted double-armed benzo-15-crown-5 derivatives are synthesized by the reactions of 4 ',5 '-bis(bromomethyl)benzo-15-crown-5 with 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, or 5-iodosalicylaldehyde. The sodium and potassium complexes are obtained by reaction of crown ether with sodium perchlorate and potassium iodide, respectively. Novel Schiff base compounds containing three groups of benzo-15-crown-5 are obtained from the condensation of aldehydes with 4 '-aminobenzo-15-crown-5. The structures of all compounds are elucidated by elemental analysis,H-1,C-13 NMR, IR, and mass spectra. The antifungal and antibacterial effects of the synthesized ligands are evaluated against pathogenic microorganisms and show varying degrees of inhibitory effects against the growth of different pathogenic strains. Graphical abstract