Two soluble fluorescent polymers, poly(2-decyloxy-5-(4 0tert-butylphenyl)-1,4-phenylenevinylene) (DtBP-PPV) and poly(2-decyloxy-1,4-phenylenevinylene) (DO-PPV), were prepared by a method similar to the Gilch procedure. The DtBP-PPV and DO-PPV have a same chemical structure except for the conjugated tert-bytulphenyl substituents in the former. The polymers are characterized by using 1 H NMR, FTIR, UV-vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies and thermogravimetric analysis (TGA). The 1 H NMR spectra show no tolane-bis-benzyl (TBB) structure defects in DtBP-PPV but some in DO-PPV. Both UV-vis absorption and PL emission peaks of the DtBP-PPV exhibit a red-shift phenomenon as compared with those of the DO-PPV. Moreover, with the DtBP-PPV and DO-PPV acting as light-emitting polymers separately, EL devices were fabricated with a sequential lamination of ITO/PEDOT/DtBP-PPV (or DO-PPV)/ Ca/Ag. The DtBP-PPV-based device shows a lower turnon voltage, a longer EL emission wavelength, and a higher brightness than the DO-PPV-based device. The maximum brightness of DtBP-PPV-based device is 57 cd/ m 2 at an applied voltage of 12 V.
A 2-year-old boy, without underlying disease, presented to our service with gradual erythema and swelling of the dorsal interphalangeal joint of the right thumb for 3 weeks (Figure 1(a)). There was no history of trauma to the thumb. He had been vaccinated with BCG (Bacillus Calmette-Guérin) Tokyo-172 strain on his left deltoid area about 2 weeks after birth. The laboratory results showed a normal differential blood count, serum creatinine level, liver enzymes, erythrocyte sedimentation rate, and C-reactive protein level. The radiograph demonstrated osteolytic change of the proximal phalanx of the right thumb (Figure 1(b)). The lesion was aspirated for pathogen identification and was treated with amoxicillin-clavunate empirically. However, no pathogen was identified and the lesion progressed. The lesion was explored surgically and a dumbbell-shaped
Pyrazole-based DHODase inhibitors have been efficient and conveniently synthesized in 51-60% yield from 3-(p-aryl)-4-cyanosydnone via regioselective 1,3-diploar cycloaddition followed by an amidation and a Ritter reaction.
In this study, a new electroluminescent poly(2-decyloxy-5-(4 0 -tert-butylphenyl)-1,4-phenylene-vinylene) (designated as DBP-PPV) with no tolane-bis -benzyl (TBB) structure defect was prepared by dehydrohalogenation of 1,4-bisbromomethyl-2-decyloxy-5-(4 0 -tert-butylphenyl) benzene (as monomer). The monomer bearing decyloxy and 4 0 -tert-butylphenyl substituents was synthesized via alkylation, bromination and Suzuki coupling reactions. The two asymmetric substituents of the monomer can suppress the formation of TBB defect during polymerization process and make the resultant polymer be soluble in common organic solvents. The structure and properties of DBP-PPV were examined by 1 H-NMR, FT-IR, UV/Vis, TGA and photoluminescence (PL) analyses. Moreover, with the DBP-PPV acting as a lightemitting polymer, a device with sequential lamination of ITO/PEDOT/DBP-PPV/Ca/Ag was fabricated. The electroluminescence (EL) spectrum of the device showed a maximum emission at around 546 nm, corresponding to a yellowish-green light. The device showed a turn-on voltage of about 8.4 V and a maximum luminescence efficiency of 0.11 cd/A at an applied voltage of 12 V.
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