Cationic Polyelectrolyte for Anionic Cyanines: An Efficient Way to Translate Molecular Properties into Material Properties

In this work, a new phosphonium-containing cationic polyelectrolyte (PE1) has been rationally designed and developed via a facile click-chemistry type postfunctionalization, which can form complexes with highly polarizable anionic cyanines to significantly reduce the strong and ran-dom cyanine-cyanine interactions (i.e. aggregation) in the solid-state. This material design strategy enables an efficient translation of the favorable molecular properties of cyanines into macroscopic material properties. One of such complexes exhibits a very large third-order susceptibility over 10-10 esu with low nonlinear optical loss suitable for all optical signal processing.