Remote interfacial electron transfer processes on nanocrystalline TiO

The kinetic study of interfacial electron transfer in sensitized nanocrystalline semiconductor is essential to the design of molecular devices performing specific light induced functions in a microheterogeneous environment. A series of molecular assemblies performing direct and remote charge injection to the semiconductor have been discussed in the context of artificial photosynthesis. A particular attention in this article has been paid to the factors that control the interfacial electron transfer processes in nanocrystalline TiO2 films sensitized with mononuclear and polynuclear transition metal complexes

Molecular rectification by a bimetallic Ru-Os compound anchored to nanocrystalline TiO2.

The coordination compound [Ru(dcb)(2)(Cl)-bpa-Os(bpy)(2)(Cl)](PF6)(2), abbreviated Ru-bpa-Os, where dcb is 4,4'-(COOH)(2)-2,2'-bipyridine and bpa is 1,2-bis(4-pyridyl)ethane, was anchored to nanocrystalline (anatase) TiO2 films for interfacial electron transfer studies. Blue or green light excitation results in the sequence of electron transfer events shown schematically where the Ru chromopihore injects an electron into the semiconductor, step 1, and the Os(II) center reduces Ru(III), step 2, to farm an interfacial charge-separated state abbreviated TiO2(e(-))\Ru-bpa-Os(III). This same charge-separated state, TiO2(e(-))\Ru-bpa-Os(III), can be formed by a novel remote electron injection process from the Os chromophore to the semiconductor solid. The electron injection rates into the semiconductor are at least 5 orders of magnitude faster than charge recombination. This is the first example of a bimetallic coordination compound that rectifies charge at a semiconductor interface

Sources of health information used by Qatari Adults, according to gender.

<p>Sources of health information used by Qatari Adults, according to gender.</p

Indicators of online health information usage.

<p>Indicators of online health information usage.</p

Study sample characteristics of 394 Adult Qatari participants, according to gender.

<p>Study sample characteristics of 394 Adult Qatari participants, according to gender.</p