Syntheses and fluorescence of salicylaldimine schiff base derivatives of 1,1′‐di(aminoethylaminocarbonylalkyl)‐2,2′‐biimidazole

Abstract

The amide‐amine, 1,1′‐di(aminoethylaminocarbonylethyl)‐2,2′‐biimidazole (DAEPB) (1), and subsequent Schiff base imine product, 1,1′‐di(salicylaldiminoethylaminocarbonylethyl)‐2,2′‐biimidazole (DSEB) (2a), have been synthesized from the ester, 1,1′‐di(ethoxycarbonylethyl)‐2,2′‐biimidazole (DEPB). Additionally, 1,1′‐di(salicylaldiminoethylaminocarbonylmethyl)‐2,2′‐biimidazole (DSMB) (2b), was prepared from its corresponding amide‐amine. All compounds were characterized with FTIR, NMR and elemental analyses. The salicylaldimines, compounds (2a) and (2b), exhibit fluorescence at 540 and 520 nm, respectively, over a broad range of excitation wavelengths.