Highly solvatochromic fluorescent naphthalimides: Design, synthesis, photophysical properties and fluorescence switch-on sensing of ct-DNA

• Published in: Bioorganic & medicinal chemistry letters 2013-01, Vol.23 (1), p.96-101
• Main Authors: Bag, Subhendu Sekhar, Pradhan, Manoj Kumar, Kundu, Rajen, Jana, Subhashis
• Format: Article
• Language: English
• Subjects: Animals; Cattle; chemistry; chloroplast DNA; DNA - chemistry; DNA - metabolism; Drug Design; fluorescence; Fluorescent Dyes - chemistry; Fluorophores; Hydrogen Bonding; Intra molecular charge transfer (ICT); Molecular Probes - chemistry; Naphthalimides - chemical synthesis; Naphthalimides - chemistry; Probes of ct-DNA; Propynyl naphthalimides; Solvatochromic; solvents; Solvents - chemistry; Spectrophotometry, Ultraviolet; Switch-on sensing
• ISSN: 0960-894X; 1464-3405
• DOI: 10.1016/j.bmcl.2012.11.003

We report the design, synthesis and photophysical properties of highly solvatochromic donor/acceptor substituted naphthalimide based fluorophores. The synthesized naphthalimides containing propargyl ends showed highly solvatochromic intramolecular charge transfer (ICT) feature as was revealed from the UV–visible, fluorescence photophysical properties of these fluorophores and DFT/TDDFT calculation. Fluorescence life times for the imide fluorophores were also measured in different solvents. The solid state photophysical property of donor substituted naphthalimide 1 showed promising for future application in material sciences. Furthermore, both the donor/acceptor substituted naphthalimide fluorophores 1–2 were exploited in sensing calf-thymus DNA via switch-on fluorescence response. The propargyl linker containing naphthalimides can further be exploited for the synthesis of labeled biomolecular building blocks. We report the design, synthesis and photophysical properties of highly solvatochromic donor/acceptor substituted naphthalimide based fluorophores. The synthesized naphthalimides containing propargyl ends showed highly solvatochromic intramolecular charge transfer (ICT) feature as was revealed from the UV–visible, fluorescence photophysical properties of these fluorophores and DFT/TDDFT calculation. Fluorescence life times for the imide fluorophores were also measured in different solvents. The solid state photophysical property of donor substituted naphthalimide 1 showed promising for future application in material sciences. Furthermore, both the donor/acceptor substituted naphthalimide fluorophores 1–2 were exploited in sensing calf-thymus DNA via switch-on fluorescence response. The propargyl linker containing naphthalimides can further be exploited for the synthesis of labeled biomolecular building blocks.