Three ortho-, meta-, and para-linked polymers derived from 9,9-dioctylfluorene (FO) and dimethoxyl-biphenyl (DMBP) were designed and synthesized via catalyst-transfer Suzuki coupling polymerization with palladium(0) catalyst as initiator. Compared to PFO, the conjugated polymers of PFO-o-DMBP, PFO-m-DMBP, and PFO-p-DMBP displayed a significantly blued-shifted absorption and emission spectra with the change of the connecting site from ortho-, meta- to para-position, and the varying degrees were ascribed to the different types of steric hindrance of ortho-, meta-, and para-linkage, which partly hinder the intermonomer rotation of the polymer backbone, giving rise to molecular configuration from linear, zigzag to intertwined structure, and resulting in shortened conjugation length. The optical bandgap calculated from the onset of absorption spectra of the three polymers in solid film are all wider than that of the PFO, indicating that the incorporating of dimethoxyl-biphenyl increased the chain-twisting hindrance and influenced the molecular conformation of the copolymer. Systematical investigation of electrochemical and photophysical properties of the conjugated polymers suggests that the incorporation of dimethoxyl-biphenyl via ortho-, meta-, and para-linkage is an efficient and economic way to modify the properties of polyfluorenes.
Five kinds of heterofluorenes (silafluorene, oxygafluorene, sulfafluorene, phosphafluorene, carbazole) and 2,5- dihexylbenzene alternative conjugated copolymers have been developed via Suzuki coupling reaction. The successful preparation of the conjugated copolymers opens a door for a new kind of host materials with high triplet state energy as excellent host materials and special optical properties with tremendous potential in the field of organic electronics without the typical defects of polyfluorene.
A new and facile procedure for the preparation of 6,6′-diiodo-5,5′-dibromo-3,3′-dimethoxylbiphenyl has been found. From this compound, a general synthetic strategy for the preparation of 1,8-dibromo-9-heterofluorenes will be developed. The Synthesis of 1,8-dibromo-9-heterofluorenes will open the door to new classes of inorganic and organometallic conjugated polymeric materials of polyheterofluorenes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.