Plane-chain hopping

The alkyl substitution forced adjacent pyrrole units on the same chain out-of-plane by at least 40°. A consequence of this was that the authors could only evaluate their data at higher temperatures (including room temperature), in terms of the assumption that interchain electronic hopping was the dominant factor in determining the macroscopically measureable electronic conductivity, rather than in/rachain hopping. Under these conditions, the... 

It is known that the polymer chains are lying in the plane of the surface.34 In a typical polymer device structure anode/polymer/cathode, the charge carriers are traveling across the polymer film, which is perpendicular to the plane of the film. Therefore, the conductivity of the film will, to a large extent, depend on the rate for interchain hopping of the carriers or on the rate for the interchain electron transfer. If a polymer film is dominated by the Ar-type aggregation style shown in Fig. 6.4, where the bulky side chains (the insulators) are trapped inside the aggregate and... 

We are not aware of work directly addressing the question of how effects of uniaxial strains should be included in many-body models. In terms of the TB band model presented in sect. 2, one can anticipate that hopping amplitudes should increase (decrease) as atoms are squeezed together (apart). Neglecting internal strain the effect of d- and 6-axis strains will be similar. Likewise, changes in the on-site Coulomb repulsion Uj and U on Cu and 0 respectively will be identical for the two strains. The behavior of interatomic 02-02 interaction Fpp likewise will not discriminate between d- and 6-axis strains. Distinction between the two in-plane strains must be due to characteristics of orthorhombicity - either interactions related directly to the chain atoms, or indirectly to the presence of the chains, such as the internal strains discussed above. 

In the smectic phase of scLCPs, interactions between the liquid-crystalline and the backbone chain moieties takes a much more dramatic form. The side chains form the strongly interacting part of the smectic layers, while the weakly interacting backbone chain completes the layer and is basically excluded from the strongly interacting part. In a well-developed smectic phase the main chain thus finds itself very nearly confined to a two-dimensional plane within the smectic layers, with occasional interlayer hopping (see Fig. 4.13(c)). 

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