Oligothiophenes charged

J. Cornil and J. L. Bredas, Nature of the optical transitions in charged oligothiophenes, Advan. Mater., 1995, 7, 295 J. Comil, D. Beljonne and J. L. Bredas, Nature of optical transitions in conjugated oligomers. 2. Theoretical characterization of neutral and doped oligothiophenes, J. Chem. Phys., 1995, 103, 842. 

Electronic and linear optical properties of charged oligothiophenes... 

Only the nitro-substituted oligothiophenes display large bathochromic shifts, large Stokes shifts, high fluorescent quantum yields, and long lifetimes for excited states. As for the other substituents, the trend is mostly noticeable for the short oligomers like terthiophenes and seems to disappear for sexithiophenes. As can be inferred from their solvatochromic effect, an intramolecular charge transfer takes place in the excited states of these molecules. 

Some dendrimers (389-391) have been reported. The thiophene-containing dendrimers are promising materials, due to the unique properties of oligothiophenes and their derivatives, such as high charge carrier mobility, efficient fluorescence, excellent stability in ambient conditions (even at elevated temperatures), and easy functionalization. 

Fully relaxed single-bond torsional potentials of oligothiophenes 16 (n = 0-2) under the interaction of the parallel external electric field (EF) constructed by point charges have been evaluated with semi-empirical AMI and PM3 calculations <2004SM(145)253>. Consistent evolutions of the torsional potential surfaces have been observed for three lineal oligothiophenes (Figure 43) as the EF increases. In particular, the equilibrium molecular geometries are deformed toward planar conformations, and the torsional barriers around the central bond are elevated. These... 

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