Spiroconjugation-enhanced intermolecular charge transport

We report charge-transport and related physical properties of terfluorenes with various C9 substitutions. Results show that by introducing slight spiroconjugation between a core chromophore and conjugated substitutions through spiro-linking, the bulky substitution not only serves as a spatial hindrance to enhance morphological stability and emission efficiency in thin films, but also bridges and enhances intermolecular charge transport under certain situations. Interestingly, such characteristics are acquired without altering major electronic properties of core chromophores, rendering it a flexible molecular scheme for tuning characteristics of functional molecules to meet various demands of different applications. (c) 2005 American Institute of Physics.