Synthesis, antimicrobial and photostability of novel push–pull tricyanofuran dyes bearing trolox and hindered amine

Abstract

Novel push–pull tricyanofuran-based dyes containing trolox or hindered amine nucleus were synthesized. The synthesis procedure involved the preparation of phenylvinyl-bridged tricyanofuran (TCF) dyes with a secondary amine or a hydroxyl terminal group, followed by the attachment of 6-hydroxyl-2, 5, 7, 8-tetramethyl-chroman-2-carboxylic acid (TROLOX) or N-alkyl-2,2,6,6-tetramethylpiperidin-4-amine (HALS) fragment. Those TROLOX or HALS-bearing chromophores displayed pronounced solvatochromic performance in various organic solvents with changing solvent polarity. The molecular structures of the generated TROLOX or HALS-containing chromophores were proved by 1H and 13C NMR and FT-IR. This could be attributed to the occurred intra-molecular charge transfer (ICT). The photodegradation of the prepared dyes were studied using dual-beam thermal lens method. The UV–Vis absorption spectra showed dramatic improvements in the photostability of the prepared TROLOX or HALS-bearing chromophores compared to the corresponding reference dyes. Due to the presence of nitrogen-containing heterocycles in their structures, the HALS-bearing chromophores displayed an antibacterial behavior to Staphylococcus aureus, Candida albicans and Escherichia coli. The colorfastness properties against light were also evaluated.

Keywords

• Push–pull tricyanofuran dyes
• TROLOX
• HALS
• Antimicrobial
• Photostability