
TY  - JOUR
A1  - Hsu, M.-A. 
A1  - Chow, T. J. 
T1  - Preparation and Luminescence Properties of Polymeric 2,5-Bis[2´-(8´´-alkoxyquinolin-2´´-yl)ethenyl]hydroquinone Derivatives
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2002
VL  - 55
IS  - 8
SP  - 499
EP  - 504
KW  - 
UR  - https://doi.org/10.1071/CH02112 
N2  - A PPV-type polymer (1) incorporating 5,5´-diquinolinyl moieties is prepared by a Yamamoto homo-coupling reaction from the dibromide (2). Since all the hydroxyl groups were alkylated, this polymer showed high solubility in most organic solvents. It can be spin-coated readily to form a thin layer in the fabrication of light emitting diode (LED) devices. The adjacent quinoline rings are twisted to form a dihedral angle due to steric hindrance, so that &#960;-conjugation is confined within each monomer unit. The emission spectra of (1) and (2) are nearly identical. The reduction potential of (1) was estimated to be &#8211;1.10 V (onset), with a band gap of 2.53 eV (490 nm). A single hetero-junction LED device fabricated by combining the films of poly(vinylkarbazol) (PVK) and (1) yielded promising results. The device ITO/PVK/(1)/Ca/Al exhibited a turn-on voltage at 6 V and reached a maximal brightness of 250 cd/m2 at 15 V. An alternate potential usage of (1) as an electron-injecting material was also explored on a green-light device using coumarin-6 as an emitter. 
ER  -

