Boron-containing organic compounds are a well-accepted class of compounds having excellent photophysical properties. These molecules are synthesized by complexing boron with organic chelates and are stabilized by the delocalization of lone-pair electrons of the hetero-atoms of the chelates into the vacant p-orbital on boron. Apart from the unique photophysical properties, the ease of synthesis and structural robustness make boron-containing molecules ideal for a variety of applications. We follow a simple self-assembly based pathway for the synthesis of boron containing molecules and use commercially available starting materials thereby minimising the number of synthetic steps. We have been successful in synthesising a variety of functionalized molecules for optoelectronics and biological applications such as flexible optical wave-guiding, anti-counterfeiting, sensing, water purification and photodynamic therapy.
Plasmon-molecule coupling has emerged as a new modality for the development of photonic devices and optically responsive materials. Metal nanoparticles in combination with dyes provide a platform to construct hybrid materials whose photophysical properties may be tuned at the nanoscale. Molecules which absorb light near to the surface plasmon resonance absorption peak of metal nanoparticles can induce changes in the photophysical and electronic properties of metal nanoparticles through plasmon-molecule interactions. We prepare nanocomposites of common dye molecules using metal nanoparticles and study their photophysical and photochemical properties. We have shown that by systematically varying the functionalities on the dye molecules it is possible to modulate the photophysical and photochemical properties of the nanocomposites and allowed them to be used as photosensitizers for photodynamic therapy and as sensors for biologically relevant substrates.
Nucleic Acid Analogues
Synthetic nucleic acids are widely used in fundamental research and also for applications in medical diagnosis and drug development. Some of them have been commercialized as drugs and several are undergoing clinical trials. We aim to develop new analogues of nucleosides and nucleic acids for therapeutic applications. We have shown that nucleoside analogues containing the hydrogen bonding face of the natural bases can be synthesized and that these molecules exhibit anti-cancer activity. We are also interested in developing new methodologies based on supramolecular chemistry to synthesize nucleic acid analogues which will add a new dimension to the nucleic acid chemistry.