Ruthenium photochemical device

TOWARDS THE DESIGN OF MOLECULAR PHOTOCHEMICAL DEVICES BASED ON RUTHENIUM BIPYRIDINE PHOTOSENSITIZER UNITS. 

Polymetallic complexes presenting directional energy migration are of much significance for the design of photochemical molecular devices. Large arrays of multiple photoactive and redox-active building blocks (of ruthenium- or osmium tris(bipyri-dine)-type for instance) have been constructed for such purposes [A. 10,8.25-8.27]. 

Luminescent and redox-reactive building blocks for the design of photochemical molecular devices mono-, di-,tri-, and tetranuclear ruthenium(n) polypyridine complexes. [G. Denti, S. Campagna, L. Sabatino, S. Serroni, M. Ciano, V. Balzani, Inorg. Chem. 1990, 29(23), 4750-4758] [ 830]. 

A novel approach to data storage applications involves a glassy carbon electrode with a coating of [Ru(bipy)2(PVP)Cl]Cl, where PVP is poly-4-vinylpyridine. The rotating electrode oxidizes iron(II) at 640 mV [the polymer coating will inhibit iron(II) oxidation until ruthenium(II) centres are oxidized to ruthenium(III)]. If the electrode is irradiated, a photochemically mediated substitution of the chloro hgand by an aquo ligand will occur and, after this radiation, a more positive potential (740 mV) is required to oxidize iron(II). Thus if the electrode potential is held between 640 and 740 mV a yes / no device is possible since irradiation will eliminate the flow of current. ... 

Kalyanasundaram K., Gratzel M. Applications of functionalized transition metal con5)lexes in photonic and optoelectronic devices. Coord. Chem. Rev. 1998 77 347-414 Kamat P.V. Photoelectrochemistry in particulate systems. 3. Phototransformations in the colloidal TiOa-thiocyanate system. Langmuir 1985 1 608-611 Kamat P.V., Bedja I., Hotchandani S., Patterson L.K. Photosensitization of nanocrystalline semiconductor films. Modulation of electron transfer between excited ruthenium complex and SnOa nanocrystalUne with an externally applied bias. J. Phys. Chem. 1996 100 4900-4908 Kamat P.V., Vinodgopal K. Environmental photochemistry with semiconductor nanoparticles. Mol. Supramol. Photochem. 1998 2 307-350... 

---