Synthesis and Properties of Indenofluorene Derivatives
Date Issued
2006
Date
2006
Author(s)
Chi, Liang-Chen
DOI
zh-TW
Abstract
A series of indenofluorene derivatives were synthesized in good yields through a common intermediate. The key intermediate is a p-phenylene diester obtained by Suzuki-Miyaura coupling reaction. Addition of aryllithium followed by ring closure under acidic condition produced different conjugated lengths of ladder-type materials. The red-shifting optical properties can be rationalized by the increases of theπ-conjugation along the long molecular axis. Both the photophysical studies and X-ray structure analysis agree with the rigidity and coplanar nature of the indenofluorene backbone. The introduction of the tolyl groups as the peripheral substitutions is highly beneficial for the thermal and morphological stability. These kind of indenofluorene-based materials, InF3、InF4 and InF5, have short emission wavelength and large energy band gap which indicate a great potential as host materials for OLED applications. Arenes bearing with different electronic properties can be introduced as the constituted units of π-conjugation backbone to perform the physical properties modulation.
The highly efficient and versatile synthetic strategies can be applied for synthesizing novel coplanar chromophores, for example, introduce new arenes such as naphthalene or benzothiophene boronic acid as the constituted units of the conjugated backbone. Carbazole–based conjugated oligomers and polymers are used as hole–transporting as well as host materials for organic light-emitting devices (OLEDs). Many research endeavors have been devoted to design carbazole derivatives for optoelectronic applications. The synthetic protocol mentioned above then was applied for the synthesis of coplanar chromophore containing with carbazole as a core structure.
We used a facile synthetic route to a new series of indenofluorene derivatives with diarylamino groups at the terminal 2,8-positions. The synthesis was achieved by bromination of InF3 followed by Pd-catalyzed amination reaction in the presence of tri-t-butyl phosphine. These compounds exhibited high thermal stability and were found to be amorphous with high Tg. The triaryldiamines exhibit strong blue photoluminescence (PL). Both triaryldiamines had an absorption maximum at 405 nm and an emission maximum at 426 nm. We will apply these materials as blue-emitting materials for OLEDs.
Subjects
茚
芴
Indenofluorene
Type
thesis
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