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Visible light generation of I-I bonds by Ru-tris(diimine) excited states.

ABSTRACT: Seven Ru-tris(diimine) compounds were prepared to study the photooxidation of iodide. Iodide oxidation results in the formation of I-I bonds, and it is therefore relevant to the conversion and storage of solar energy. Iodide oxidation is also a key step for electrical power generation in dye-sensitized solar cells. The mechanistic details of iodide oxidation and I-I bond formation were elucidated through time-resolved spectroscopic measurements. Bimolecular electron-transfer reactions between Ru-tris(diimine) excited states and iodide first yielded the iodine atom that subsequently reacted with excess I(-) to yield the I-I bond of diiodide (I(2)•-)). An important finding was that excited-state iodide oxidation was rapid (k > 10(9) M(-1) s(-1)) even for thermodynamically uphill reactions. These results indicated that iodide oxidation to the iodine atom may account for a significant fraction of sensitizer regeneration within dye-sensitized solar cells.

SUBMITTER: Farnum BH

PROVIDER: S-EPMC3465397 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature

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Visible light generation of I-I bonds by Ru-tris(diimine) excited states.

Farnum Byron H BH Jou Jeffrey J JJ Meyer Gerald J GJ

Proceedings of the National Academy of Sciences of the United States of America 20120507 39

Seven Ru-tris(diimine) compounds were prepared to study the photooxidation of iodide. Iodide oxidation results in the formation of I-I bonds, and it is therefore relevant to the conversion and storage of solar energy. Iodide oxidation is also a key step for electrical power generation in dye-sensitized solar cells. The mechanistic details of iodide oxidation and I-I bond formation were elucidated through time-resolved spectroscopic measurements. Bimolecular electron-transfer reactions between Ru ...[more]

PMID: 22566656

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