Jae-Yun Jaung

New syntheses and spectral properties of diazepine fluorescent dyes with non-planar molecular structure

Two types of new diazepine fluorescent dyes were synthesized by the condensation of N-(4-substituted-4-oxo-2-buten-2-yl)diaminomaleonitrile and 2,3-dicyano-6H-1,4-diazepines with an arylaldehyde. Regioselective condensation reaction are observed and their reactivities are evaluated from their optimized molecular structures obtained by means of the ab initio molecular orbital calculation methods. Substituent effects of the donor moiety to absorption and fluorescent properties in solution were correlated with chromophoric systems with regard to the non-planar diazepine moiety. A strong intramolecular charge-transfer chromophoric system of dyes are confirmed and its large Stokes shift of over 100 nm resulted in emission of red fluorescence. These dyes are of current interest as a red light emitter for electroluminescence devices.

Effect of Splitting and Finishing on Absorption/Adsorption Properties of Split Polyester Microfiber Fabrics

Nylon/polyester (N/P) conjugate fibers are split by alkaline hydrolysis and then finished with an antimicrobial agent, and the effect of splitting and finishing on the absorption/adsorption properties of the microfibers is studied. The split microfiber fabrics vary in weight loss and pore structure depending on the various splitting conditions. The absorption behavior of microfiber fabrics is analyzed by the degree of splitting, shrinkage, fabric density, and weight loss. Optimum splitting conditions are investigated for superior absorption rate and capacity. Even and complete splitting produces fine fibers closely packed in a parallel structure, which creates capillary channels that transport water into fabric treated at 140°C with about 10% weight loss. Values of adsorption, add-on (%), and good durability to repeated laundering and dry cleaning of the agent on the finished N/P microfiber fabrics are high, in contrast to a conventional fiber fabric. This is most likely due to the high surface area and surface irregularities caused by splitting and hydrolysis. The absorption capacity of the finished fabrics decreases because some pore spaces are filled with the adsorbed agent, while the absorption rate increases due to capillary sorption. The water absorption instrument newly devised for this study is an excellent measurement system. It is possible to measure the amount of water absorption with time, and to distinguish the differences in absorbency of the split N/P microfiber knitted fabrics, which have pore structures that vary in shape and size, created by and deformed during the splitting and finishing process.

Synthesis of New Single Black Pigments Based on Azo and Anthraquinone Moieties for LCD Black Matrix

Based on azo group and anthraquinone moiety, new black matrix pigment materials AAQ and DAAQ were synthesized for the first time through Suzuki C-N coupling. As a result of verifying UV-visible absorption spectra of the synthesized materials, DAAQ was found to absorb the entire visible region in 400 ∼ 800 nm in solution state with high extinction coefficient of 8.1 × 103 L/cm · mol. Realization of black color using a single material is expected to be useful for black matrix application. Also in film state made through spin coating, both AAQ and DAAQ absorbed the entire visible region.

New Fluoranthene Derivatives in Electroluminescence

7,8,10-triphenylfluoranthene [TPF], 7,10-diphenyl-8-(1-naphthyl) fluoranthene[DPNF], 7,10-diphenyl-8-(9-phenanthrenyl)fluoranthene[DPPF] were synthesized by using the Knoevenagel condensation and Diels–Alder addition. PL maximum values of TPF, DPNF and DPPF are 458 nm, 460 nm and 461 nm, respectively. TPF showed sky-blue CIE value of (0.192, 0.269) and 3.27cd/A at 10 mA/cm2. DPNF also showed sky-blue CIE value of (0.189, 0.262) and 3.24 cd/A at 10 mA/cm2. DPPF showed much better operating voltage, luminance and power efficiency of 3.96 cd/A and 2.11 lm/W although it had worse C.I.E. value than TPF.

Syntheses and thermal properties of 5,10-disubstituted-2,3,7,8-tetracyano-5,10-dihydrodipyrazino[2,3-b:2′,3′-e]pyrazines and polymeric porphyrazines derived from 2,3-dichloro-5,6-dicyanopyrazine

Intermolecular cyclization of 2-alkylamino-3-chloro-5,6-dicyanopyrazine2 in the presence of tributylamine in N,N-dimethylformamide (DMF) gave 5,10-disubstituted-2,3,7,8-tetracyano-5,10-dihydrodipyrazino[2,3-b:2′,3′-e]pyrazines3, which showed strong mesomorphic property and were anticipated as new chromophoric system for functional dye materials. Absorption spectra, fluorescent properties and other physical properties were correlated with their chemical structures. Vanadyl oligomeric porphyrazine with long alkyl groups synthesized from3 had satisfactory solubility in tetrahydrofuran (THF), diethyl ether and dimethylsulfoxide (DMSO). The syntheses and characterization of vanadyl polymeric porphyrazines derived from3 with long alkyl groups are reported.

Synthesis and Luminescent Properties of Poly(alkylated indenopyrazine) and Its Copolymer Containing an Alkylated Spirofluorene Moiety

We have synthesized new alkylated indenopyrazine homopolymer and its copolymer having an alkylated spirofluorene moiety. Poly(6,6,12,12-(Tetra-2-ethylhexyl)-6,12-Dihydrodiindeno[1,2-b:1,2-e]pyrazine-2,8-diyl) [PEHIP] and Poly(6,6,12,12-(tetra-2-ethylhexyl)-6,12-dihydrodiindeno[1,2-b:1,2-e]pyrazine-co-2′,3′,6′,7′-tertrakis-octyloxy-9-spirofluorene) [PEHIPSF] were polymerized by using Yamamoto reaction. PEHIP and PEHIPSF showed the PL maximum values of 470 nm and 454 nm in PL spectra. The PEHIPSF was fabricated into an EL device and it exhibited the EL maximum value of 463 nm.

Synthesis and keto–enol isomerism of 1-alkyl-2-methyl-5,6-dicyano-3-[2-(5-alkylamino-2,3-dicyanopyrazin-6-yl)-1-hydroxyethenyl]-pyrrolo[2,3-b]pyrazine

Abstract Reaction of 2-alkylamino-3-chloro-5,6-dicyanopyrazine 2 with 2,4-pentanedione in the presence of sodium hydride in benzene gave 2-methyl-3-acetyl-5,6-dicyanopyrrolo[2,3- b ]pyrazine, which was further reacted with 2 to give the keto–enol mixtures of 3-[1-hydroxy-2-(3-alkylamino-5,6-dicyanopyrazine)-ethen-2-yl]-5,6-dicyanopyrrolo[2,3- b ]pyrazine 4 . The keto-form of 4 is colorless in chloroform but red in dimethylsulfoxide (DMSO) as an enol-form. Their absorption spectra and electronic properties were correlated with their chemical structures.

Synthesis and optical properties of tetrapyrazinoporphyrazines containing asymmetrical alkyl chains and t-butylphenyl groups

Tetrapyrazinoporphyrazine magnesium complexes with four long alkyl groups and four 4-tert-butyl phenyl groups at the peripheral positions were synthesized from 2,3-dicyano-5-(4-tert-butylphenyl)-6-alkyl pyrazine derivatives using freshly prepared solutions of magnesium butoxide in n-butanol. The corresponding metal-free derivatives were obtained through treatment with p-toluenesulfonic acid. The resulting chromophores contained alkyl chains substituted at their peripheries and showed good solubility in organic solvents. The fluorescence of the tetrapyrazinoporphyrazine magnesium complexes was greatly influenced by the intermolecular aggregation. Q band spectra of the porphyrazine magnesium complexes in DMF exhibited the characteristic patterns of the monomeric species, with fluorescence maxima at 653–658 nm. These new compounds were characterized using UV-visible spectroscopy, MALDI-TOF-MS and 1H NMR spectroscopy.

Synthesis and Characterization of Novel Tetrapyrazinoporphyrazine Derivatives Containing Morpholine and tert-Butyl Group

Tetrapyrazinoporphyrazine magnesium complexes were synthesized from 2,3-dicyano-5-(4-alkylphenyl)-6-(4-morpholinophenyl)pyrazine derivatives using freshly prepared solutions of magnesium butoxide in n-butanol. The corresponding metal-free derivatives were obtained by treatment with p-toluenesulfonic acid. Copper complexes were successfully synthesized using excess cuprous chloride and DBU (1,8-diazabicyclo[5,4,0]-7-undecene) as a catalyst in o-dichlorobenzene under reflux. The tetrapyrazinoporphyrazines were characterized by elemental analysis, UV-visible spectra, IR, MALDI-TOF Ms and 1H-NMR spectra.

Substituent Effect of Fluoranthene Derivatives in Electroluminescence

7,8,10-triphenylfluoranthene [TPF], 7,10-diphenyl-8-p-tolylfluoranthene [DPTF] and 7,10-diphenyl-8-p-cyanophenlyfluoranthene [DPCF] were synthesized by using the Knoevenagel condensation and Diels–Alder addition. TPF showed sky-blue CIE value of (0.192, 0.269) and 3.27cd/A at 10 mA/cm2. DPTF also showed sky-blue CIE value of (0.185, 0.252) and 2.31cd/A at 10 mA/cm2.