The influence of the linkage pattern on the optoelectronic properties of polysilafluorenes: a theoretical study.

Polysilafluorenes have recently received increasing attention for a wide range of optoelectronic applications due to their improved performance over polyfluorenes and polycarbazoles. To reveal their molecular structures, optoelectronic properties, and structure-property relationships, a systematic study of the influence of the linkage pattern on the optoelectronic properties of polysilafluorenes was performed via quantum chemistry calculations. The optimized geometries, electronic properties, frontier molecular orbitals, singlet and triplet energies, ionization potentials, electron affinities, reorganization energies, and absorption and circular dichroism spectra of the model compounds have been calculated and analyzed. The great impacts of the linkage pattern on the structural, electronic, and optical properties of the silafluorene-based materials have been observed, and the effect mode of the linkage pattern has been discussed. Good coordination between the theoretical and experimental results has been found. The unreported poly(1,8-silafluorene)s are expected to be very interesting optoelectronic materials with high electronic bandgap (E(g)) and triplet energy ((3)E(g)), high electron injection property, high hole and electron transport properties, strong circular dichroism signals, and modest effective conjugation length, which can be used as high-performance blue or deep-blue light emitting diodes, ambipolar host materials for blue phosphorescent emitters, and helically chiral conjugated materials.