Pyrene functional poly(vinyl alcohol) by "click" chemistry

Side-chain pyrene functional poly(vinyl alcohol) (PVA) was synthesized by using "click chemistry" strategy. First, partial tosylation of PVA with p-toluene sulfonyl chloride were performed. The resulting PVA-Ts polymer was then quantitatively converted into poly(vinyl alcohol)-azide (PVA-N ₃) in the presence of NaN₃/DMF at 60°C. Propargyl pyrene was prepared independently as a photoactive click component. Finally, azido functionalized PVA was coupled to propargyl pyrene with high efficiency by click chemistry. Incorporation of pyrene functionality in the resulting polymer was confirmed by spectral analysis. It is also shown that pyrene functionalized PVA (PVA-Py) exhibited characteristic fluorescence properties and improved solubility in highly polar solvents such as water, DMSO, and DMF as well as less polar solvent such as THF compared with pristine PVA.