Pentacene reorganization energy

Overall, the intramolecular reorganization energies in tetracene (0.11 eV) and pentacene (0.10 eV) rank among the smallest values that have been calculated or measured for molecules. A smaller value of A. (0.045 eV) has been found only in the case of phthalocyanine [39]. 

The origin of the small reorganization energy valnes in tetracene and pentacene can be traced to a combination of macrocyclic rigidity and full delocalization of the frontier molecular orbitals [24,26,27], Accordingly, other molecules that have been found to present small intramolecular values are fullerenes, as described by Devos and Lannoo [43], phthalocyanines [39,44], or discotic macrocycles [45],... 

FIGURE 1.1.9 Evolution of the hole mobility as a function of the magnitude of the external reorganization energy in a one-dimensional array of pentacene molecules separated by 4 A. 

Table 2.2.3 gives values of calculated reorganization energy and transfer integral for the polyacene series [27]. It can be seen that localized transport is expected for naphthalene and anthracene and delocalized transport for pentacene tetracene is located in between these two extreme cases. 

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