Synthesis of a Polymeric Electron Acceptor Based on Perylenediimide-Bridged Ladder Polysiloxane

A soluble perylenediimide (PDI) bridged ladder polysiloxane (PDI-LPS) was prepared using ladder superstructure (LS) directed dehydration polycondensation. LS was first assembled via synergistic interactions of hydrogen-bonding and pi-pi stacking of tetrasilanol monomers (M2s) as verified from XRD, Si-29 NMR, and VPO characterizations. The ladder regularity of PDI-LPS was confirmed by a narrow half-peak width (Delta) of <I ppm for SiO2/2 unit in the Si-29 NMR spectra. The alignment of ladder chains was also demonstrated from high-resolution transmission electronic microscopy (HR-TEM) observations. We successfully used ladderlike structure to chemically confine PDI cores within one-dimensional polymeric semiconductor. The resulting PDI-LPS not only retained PDI's optoelectronic properties but also gained enhanced solubility in common organic solvents and improved thermal stability.