Perylene monoimide and naphthalene-annulated [3,3,3]propellanes: synthesis and device applications†
Rigid three-dimensional polycyclic aromatic hydrocarbons (3D PAHs) are garnering great interest due to their unique molecular shapes and interesting optoelectronic properties. Herein we report the synthesis of two 3D PAHs with perylene monoimide (PMI) and naphthalene subunits fused on [3,3,3]propellanes. The resulting compounds (P-1 and P-2) are unambiguously characterized by spectral analysis and theoretical calculations. It is found that the subunits can significantly influence the electronic properties and electron communications in 3D PAHs. In contrast to the naphthalene subunit, the PMI subunit leads to the enhancement of electron communication in 3D PAHs and amplifies the absorption coefficients when compared to the individual PMI subunit. In addition, UV-vis measurement suggests the presence of homoconjugation between the subunits. These compounds exhibit p-type behaviors with the mobilities on the order of 10−5 to 10−4 cm2 V−1 s−1. Additionally, these 3D PAHs show strong fluorescence and are employed as emitters for organic light-emitting diodes.