Electronic charge, effect copolymers

The synthesis, characterization, electrical conductivity, and field effect mobility of a series of novel soluble N-alkyl dithieno[3,2-b 2, 3 -d]pyrrole (DTP) and thiophene (TH)-based copolymers (DTP-co-THs) were reported (06MM1771 08JA13167). The incorporation of DTP units extends n conjugation, and the introduction of thiophene subunits imparts good solubility, high conductivity, and high charge carrier mobility. Therefore, the incorporation of DTP units and various substituted thiophenes into the polymer backbone affords the ability to enhance the solubility, lower the band gap, and achieve the enhanced electronic properties. 

Photo-induced electron transfer between [Ru(bpy)3]2+-like centres covalently bound to positively-charged polymers (N-ethylated copolymers of vinylpyridine and [Ru(bpy)2(MVbpy)]2+) and viologens or Fe (III) has been studied using laser flash photolysis techniques. It is found that the backbone affects the rates of excited state quenching, the cage escape yield, and the back electron transfer rate because of both electrostatic and hydrophobic interactions. The effect of ionic strength on the reactions has been studied. Data on the electron transfer reactions of [Ru(bpy)3]2+ bound electrostatically or covalently to polystyrenesulphonate are also presented. 

This indicates that for any feed composition, the copolymer formed will have an equimolar regularly alternating composition. The chemistry behind these systems has been extensively discussed in the literature, and the charge-transfer complex concept was for a long time the prevailing theory to explain this behavior [73-75]. More recently, Hall and Padias [76, 77] have proposed an alternate explanation based on polar effects when an electron-donor and an electron-acceptor monomer interact. This last theory has the additional virtue of explaining the fact that many... 

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