In order to develop a host polymer material applicable to solution-processed organic light-emitting diodes, a novel polymer consisting of the (1,1'-binaphthalene-6,6'-diyl)bis(9
H-carbazole) monomer units was prepared, and a polymer light-emitting diode (PLED) containing a phosphorescent material was fabricated using the obtained polymer. The palladium-promoted Buchwald-Hartwig-type cross-coupling reaction of 2,2'-alkoxy-6,6'-dibromo-1,1'-binaphthalene with 9
H-carbazole successfully led to the introduction of two carbazole groups to the binaphthalene skeleton. One of the obtained bis(carbazole) derivatives was converted to an acrylate-functionalized compound (
mono-BNCz) in 3 synthetic steps, which was polymerized using a radical initiator to afford a novel polymer (
poly-BNCz,
Mw = 9680,
Mn = 6580, and PDI = 1.47). The obtained polymer exhibited good solubility in common organic solvents such as chloroform and toluene, and provided excellent thin film formation by a solution process. Using
poly-BNCz as a host polymer, a PLED containing a green-phosphorescent iridium(III) complex as an emitting dopant was fabricated. Upon application of an increasing voltage, green electroluminescence based on the emitting dopant was obtained from the PLED, and therefore, it was found that
poly-BNCz is applicable to solution-processed OLEDs as a host material.
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