Inherent Photoluminescence Properties of Poly(propyl ether imine) Dendrimers

Hydroxyl group terminated poly(propyl ether imine) dendrimers of 1 to 5 generations absorb in the region of 260−340 nm, in MeOH and aqueous solutions. Excitation of a solution of the dendrimers at 330 nm led to an emission at ∼390 nm. The emission intensities increased under acidic pH and in more viscous solvents. The presence of air did not affect the emission profiles, as also aging of a dendrimer solution for prolonged periods. Lifetime measurements show at least two species responsible for the emission. Anions perchlorate, periodate, nitrite, and pyridinium methyliodide quenched the fluorescence efficiently, among several anions tested.