Electrical properties supramolecular organization

J.-M. Verilhac, G. LeBlevennec, D. Djurado, F. Rieutord, M. Chouiki, J.-P. Travers and A. Pron. Effect of macromolecular parameters and processing conditions on supramolecular organization, morphology and electrical transport properties in thin layers of regioregular poly(3-hexylthiophene). Synth. Met. 156(11-13), 815-823... 

More interestingly, the self-organization of Pc-C ) dyads on surfaces (by drop-casting technique) and in liquid crystals has also been reported. High electrical conductivity values were measured by conductive-AFM for some of these Pc-containing nanostructures, pointing to an evident relationship between the electrical properties and the supramolecular order of the Pc-Ceo conjugates. 

The above devices inspired scientists to develop solid-state MSTJ devices made from a [2]pseudorotaxane and [2]rotaxane (Figure 76) in which hydrophobic and hydrophilic regions were directly incorporated into the molecular structure to allow self-organization. ° The electrical properties were found to be highly dependent on the supramolecular structure, the presence of bistability within the (super)molecule, and the organization of the Langmuir-Blodgett film. The devices exhibited a... 

In this section representative examples are introduced, which combine self-organization (as defined in Section 1) and supramolecular structure formation. The specific features in designing electrical properties will be discussed in the next section. 

It was also observed that conjugated polymers that are also electrical conductors (see Chap. 10) exhibit optical activity that depends critically on their structural organization [78]. Thus, strong chiroptical properties can be obtained firom substituted polythiophene [79] (Chap. 10) with optically active side chains, especially when the monomers are coupled within the polymer in a regioregular head-to-tail fashion. Actually, optical activity of these materials is only found when the polymers are aggregated at low temperature, in poor solvent, or in solution cast films. This contrasts with other optically active polymers, like polypeptides, poly(l-alkynes) and polyisocyanates that show an optically active conformation of the main chain in the absence of supramolecular association. 

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