We described the synthesis of a series of well-defined polystyrene based light harvesting materials, in which the polystyrene backbone was prepared through nitroxide-mediated living radical polymerization (NMP), with degree of polymerization (DP) varying from 35 to 170. The chromophores in these polymers, polypyridine Ru (II), were fully attached to the polystyrene backbone by the alkyene-azide click chemistry. The polymer structures were confirmed by nuclear magnetic resonance and infrared spectroscopy. We evaluated the photophysical and electrochemical properties of the Ru-polypyridine polymers in MeOH and acetonitrile. The polymeric chromphores exhibited similar absorption and emission spectra compared to monomeric chromophore, while the polymers showed distinct life time and quantum yield versus different counter ions or solvents. Molecular dynamics simulation of the polypyridylruthenium derivatized polystyrene in different solvents support the energy transfer and experimental photophysic studies. Based on the similar strategy, the first chromophore-water oxidation catalysts (WOC) polymer assembly was synthesized, with Ru(II)-H2O(bpy)(terpy)(water oxidation catalyst) and Ru(II)(bpy)3 (chromophore) units assembled to well-defined polystyrenes with ratio of 1:4. The preliminary data from emission and life time studies revealed the fast intra-chain electron transfer process in the WOC polymer assembly. Upon light excitation, the electrons would transfer from water oxidation catalyst centers to adjacent chromophore units in 15 ns. This effect was expected to enhance the TOF of water oxidation reactions. Our research involving the water oxidation catalysts (WOC) polymer assembly supplies an alternative way to make efficient catalyst-chromophore assemblies.

Preparation of polypyridylruthenium light harvesting polymers and application in water oxidation catalyst assembly

249th National Meeting (2015)

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