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Synthesis of nonplanar bipyridyls bridged by disilane and disiloxane and their phosphorescent copper complexes
Author(s) -
Ohshita Joji,
Kai Takashi,
Adachi Yohei,
Yamaji Kosuke,
Nakamura Masashi,
Watase Seiji,
Mori Shingo,
Matsuyama Noritsumi
Publication year - 2020
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.5306
Subject(s) - chemistry , disilane , disiloxane , phosphorescence , dopant , photoluminescence , electroluminescence , photochemistry , photoisomerization , copper , crystallography , fluorescence , optoelectronics , layer (electronics) , doping , silane , optics , organic chemistry , catalysis , materials science , physics , isomerization
Disilane‐ and disiloxane‐bridged bipyridyls ( DSBPy and DSOBPy ) were prepared and their optical properties were investigated in comparison with those of previously reported monosilane‐ and monogermane‐bridged counterparts. The UV–visible absorption and photoluminescence bands of DSBPy and DSOBPy were blue‐shifted as a result of elongation of the bridging units from monosilane and monogermane to disilane and disiloxane, likely due to the enhanced twisting of the bipyridyl units. Phosphorescent complexes DSBPy–Cu and DSOBPy–Cu were prepared by the interaction of DSBPy and DSOBPy with Cu 2 I 2 (PPh 3 ) 2 . X‐ray diffraction studies of their single‐crystal structures revealed polymeric structures composed of repeat units of DSBPy or DSOBPy and [Cu I I(PPh 3 )] 2 . Organic light‐emitting diodes with the ITO/PEDOT:PSS/ DSBPy–Cu or DSOBPy–Cu :PCTSQ/TAZ/Al structure were fabricated to examine the applications of the complexes as electroluminescent materials. The devices emitted yellow light with emission maxima at approximately 600 nm, and maximal luminance reached 120 and 190 cd m −2 for devices based on DSBPy–Cu and DSOBPy–Cu , respectively. The performance of the DSOBPy–Cu ‐based device was improved by using TAZ as the dopant of the emissive layer, and luminance was increased to 390 cd m −2 .