Synthesis and spectral studies of coumarin derivatives as fluorescent probes for Fe3+

Abstract

Three novel coumarin derivatives were designed and facilely synthesized, namely 6-[bis-(2-acetoxyethyl)aminomethyl]-4-methyl coumarin (BAMC), 4-(trans-4-methylformate-styryl)-6-[bis-(2-acetoxyethyl)aminomethyl]-coumarin (TSAC) and Trans-4-[2-(benzimidazole-2-substituted)vinyl]-6-methyl coumarin (TBVC). The synthesis route via various reactions including Pechmann, Wittig and substitution, etc. Three strategies are applied in the construction of the coumarin fluorescent probe. That is the electron push-pull effect, extended electronic conjugated system, as well as the strong fluorescence emission group. The compounds BAMC and TSAC are proved to be selective Fe³⁺ fluorescent probes based on ICT mechanism. TBVC exhibits strong fluorescent emission in tetrahydrofuran. The relationship between the structure and fluorescence mechanism for coumarin probes were explored.