Spirobenzofluorene linked anthracene derivatives: Synthesis and application in blue fluorescent host materials

摘要

Blue light-emitting anthracene-based host materials with a spiro[benzo[c]fluorene-7,9'-fluorene] core, 5-(10-(naphthalen-2-yl)anthracen-9-yl)spiro[benzo[c]fluorene-7,9'-fluorene] (NA-SBFF) and 5-(10-(4-(naphthalen-l-yl)phenyl)anthracen-9-yl)spiro[benzo[c]fluorene-7,9'-fluorene](NPA-SBFF), were designed and synthesized via two-step Suzuki coupling reactions. Introduction of a spiro group into the structure of the anthracene moieties lead to a reduction in crystallization tendency, and a high glass transition temperature was observed. Typical blue fluorescent organic light emitting diodes with the configuration of ITO/N,N'-diphenyl-N,N'-bis[4-(phenyl-m-tolyl-amino)phenyl]biphenyl-4,4'-diamine (DNTPD)/N,N'-di(l-naphthyl)-N,N'-diphenylbenzidine (NPB)/HOST: Dopant/tris(8-hydroxyquinoline)alurninum (Alq3)/LiF were developed using SBFF-type anthracene derivatives as a host material and N,N,N',N'-tetraphenylspiro [benzo[c]fluorene-7,9'-fluorene]-5,9-diamine (TPA-SBFF) as a dopant material. A device obtained from NA-SBFF doped with TPA-SBFF showed blue color purity of 0.146 and 0.167, a luminance efficiency of 8.65 cd/A, and an external quantum efficiency >6.01% at 8.0 V.