Polymeric Nonlinear Absorption Chromophore Array From Controlled Radical Polymerization And "Click" Chemistry

A polyacrylate with pendant nonlinear absorption (NLA) chromophores was prepared via the reversible addition-fragmentation (RAFT)-click synthetic strategy. The polyacrylate backbone of the NLA polymer was constructed by reversible addition-fragmentation (RAFT) polymerization and subsequently modified to azide-containing "clickable polymers". Platinum acetylide chromophores that exhibit NLA via both two-photon absorption (TPA) and excited-state absorption (ESA) mechanisms were subsequently attached to the azide-substituted polyacrylate via copper(I)-catalyzed azide-alkyne cycloaddition. The resulting polymer exhibits similar photophysical properties to the platinum acetylide precursor chromophore, including steady-state absorption and emission, triplet-triplet transient absorption, and nonlinear absorption properties. In addition, the resulting polymers can be spin-coated to afford an optically transparent film, which also preserved the nonlinear absorption characteristics of the chromophores.