• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1414-1420
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• 2013

Five novel spiro[benzo[c]fluorene-7,9'-fluorene] based dyes, including 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-5-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (7), 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-9-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (8), 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-2'-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (9), 9-[spiro[benzo[c]fluorene-7,9'-fluoren]-9-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (10), and 2'-[spiro[benzo[c]-fluorene-7,9'-fluoren]-2'-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (11) were successfully prepared from the corresponding halogen and boronic acid derivatives through the Suzuki coupling reaction, respectively. Chemical structures were confirmed by $^1H$ nuclear magnetic resonance (NMR), $^{13}C$ NMR, Fourier transforminfrared spectrscopy, mass spectroscopy, and elemental analysis. The thermal properties were determined by differential scanning calorimetry and thermal gravimetric analysis. The relationships between the optical and electrochemical properties and the combined positions between these dimers were systematically investigated using UV-vis, photoluminescence (PL), and photoelectron spectroscopy. These five dimers exhibited high fluorescent quantum yields and good morphological stability with high glass transition states > $174^{\circ}C$. Dimer 7 showed a UV absorbance peak at 353 nm, emission PL peak at 424 nm, and quantum efficiency of 0.62 in a cyclohexane solution.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2287-2294
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• 2012

Deep blue fluorescent host materials based on a novel spiro[benzo[c]fluorene-7,9'-fluorene] core structure with side aromatic wings in the 5- and 9-positions, namely, 5,9-di(naphthalen-2-yl)spiro[benzo[c]fluorene-7,9'-fluorene] (DN-SBFF), 5,9-bis(4-t-butylphenyl)spiro[benzo[c]fluorene-7,9'-fluorene] (BP-SBFF), and 5,9-bis(4-fluorophenyl)spiro[benzo[c]fluorene-7,9'-fluorene] (FP-SBFF), were designed and successfully prepared using the Suzuki reaction. The physical properties of these materials and their EL characteristics as blue host materials doped with N,N,N',N'-tetraphenylspiro[benzo[c]fluorene-7,9'-fluorene]-5,9-diamine (TPA-SBFF) were investigated. The device used comprised ITO/N,N'-diphenyl-N,N'-bis[4-(phenyl-m-tolyl-amino)phenyl]-biphenyl-4,4'-diamine (DNTPD)/N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB)/(FP-SBFF):dopant x%/tris(8-hydroxyquinoline)aluminum ($Alq_3$)/LiF. The device obtained using FP-SBFF doped with TPA-SBFF showed high color purity (0.13, 0.18) and an efficiency of 6.61 cd/A at 7 V.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1475-1482
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• 2011

New spiro[benzo[c]fluorene-7,9'-fluorene] (SBFF)-based blue host materials, 9-phenyl-SBFF (BH-4P) and 5,9-diphenyl-SBFF (BH-6DP), were successfully prepared by spiro-formation of 9-phenyl-7H-benzo[c]fluoren-7-one with 2-bromobiphenyl via lithiation and reaction of 5,9-dibromo-SBFF with phenylboronic acid through the Suzuki reaction, respectively. Diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]-amine (BD-1) and N,N-diphenyl-N',N'-diphenyl-SBFF-5,9-diamine (BD-6DPA) were used as dopant materials. Blue OLEDs with the configuration ITO/N,N'-bis-[4-(di-m-tolylamino)phenyl]-N,N'-diphenylbiphenyl-4,4'-diamine (DNTPD)/bis[N-(1-naphthyl)-N-phenyl]benzidine (NPB)/host:5% dopant/SFC-137/Al-LiF were prepared from the two host materials doped with BD-1 and BD-6DPA dopants and the devices composed of BH-4P and BH-6DP doped with BD-6DPA showed blue EL spectra at 458 and 463 nm at 7 V and luminance efficiencies of 4.58 and 4.88 cd/A, respectively.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1639-1646
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• 2014

A series of novel fused-ring spiro compounds, spiro[benzo[ij]tetraphene-7,9'-fluorene] (SBTF) derivatives containing an end-capping aryl substituent at both the C3 and C10-positions hasbeen designed and synthesized via multi-step Suzuki coupling reactions. 3-(1-Naphthyl)-10-phenylSBTF (1N-PSBTF), 3-(2-naphthyl)-10-phenylSBTF (2N-PSBTF) and 3-[4-(1-naphthyl)phenyl]-10-phenylSBTF (NP-PSBTF) showed improved glass transition temperatures ($T_g$) with good thermal stability. Their photophysical, electrochemical, and electroluminescent properties were investigated and were used to construct blue organic light emission diodes (OLEDs). The typical OLED devices showed excellent performance; the NP-PSBTF-based device exhibited highly efficient deep blue-light emission with a maximum efficiency of 5.27 cd/A (EQE, 4.63%) with CIE (x = 0.133, y = 0.144). According to these characteristics, these deep-blue light emitting materials have sufficient potential for fluorescent OLED applications.