Synthesis and properties of water-soluble fluorescent 2-borylazobenzenes bearing ionic functional groups

Water-soluble fluorescent azobenzenes have been synthesized by quaternization of 2-[bis(pentafluorophenyl)boryl]azobenzenes bearing dimethylamino groups with iodomethane or propanesultone. The 2-borylazobenzenes both dissolve and fluoresce in water. The double introduction of ionic moieties provides the azobenzenes with higher water solubility. Dynamic light scattering and scanning electron microscopy measurements indicate that the 2-borylazobenzenes aggregate in water. They are expected to be applied in aqueous environments.