• Bulletin of the Korean Chemical Society
• /
• v.34 no.1
• /
• pp.42-48
• /
• 2013

Potassium N-heterobiaryltrifluoroborates were successfully prepared via a selective Cu-catalyzed C-N coupling reaction. The $BF_3K$ moiety was well tolerated under the reaction conditions involving CuI and dimethyl-ethylenediamine (DMEDA) in the presence of DMSO. The Pd-catalyzed Suzuki-Miyaura cross couplings of potassium N-heterobiaryltrifluoroborates with bromoarenes were studied to prepare the N-heterotriaryl compounds. Moreover, homocoupling, iodination, and hydroxylation of potassium N-heterobiaryltrifluoroborates provided the corresponding products in high yields.

• Advances in nano research
• /
• v.3 no.2
• /
• pp.67-79
• /
• 2015

Air stable nanoparticles were prepared from cobalt sulphate using tetra butyl ammonium bromide as surfactant and sodium borohydride as reductant at room temperature. The cobalt nanocolloids in aqueous medium were found to be efficient catalysts for the degradation of toxic organic dyes. Our present study involves degradation of Methylene Blue and Rhodamine-B using cobalt nanoparticles and easy recovery of the catalyst from the system. The recovered nanoparticles could be recycled several times without loss of catalytic activity. Palladium nanoparticles prepared from palladium chloride and the same surfactant were found to degrade the organic dyes effectively but lose their catalytic activity after recovery. The cause of dye colour discharge by nanocolloids has been assigned based on our experimental findings.

• Korean Chemical Engineering Research
• /
• v.56 no.6
• /
• pp.792-797
• /
• 2018

We have explained the synthesis of novel phenanthrene and pyrene substituted phthalocyanines (PC-PHE and PC-PYR) and fully confirmed the structures by its spectral, photo physical and elemental analysis. For these phthalocyanines we checked the UV-Visible absorbance in PGMEA and chloroform and transmittance checked in PGMEA. The transmittance results suggested that these phthalocyanines are showing more than 90% transmittance at the 450-550 nm region. These synthesized molecules are nicely soluble in almost all industrial solvents. We checked the aggregation property of these phthalocyanines in PGMEA, and the results suggested no any aggregation for these molecules in PGMEA. The thermogravimetric analysis results concluded that PC-PHE and PC-PYR had high thermal stability. All studies explain that these new phthalocyanines are more suitable for LCD green color filter application.

• Microbiology and Biotechnology Letters
• /
• v.51 no.4
• /
• pp.333-352
• /
• 2023

Transaminase represents the most important biocatalysts used for the synthesis of chiral amines due to their stereoselectivity. They allow asymmetric synthesis with high yields and enantioselectivity from their corresponding ketones. Due to their environmentally friendly access for the preparation of chiral amines, they have attracted growing attention in recent times. Thus, the production of chiral compounds by transaminase catalysed reactions is considered as an important application in synthetic organic chemistry. Therefore, transaminase is considered to be an important enzyme in the pharmaceutical and chemical industries. ω-Transaminase holds great potential because of its wide substrate specificity thus making it a suitable enzyme to be used at an industrial scale. This review highlights the reaction mechanism, classification, substrate specificity, and biochemical properties. The review also showcases the application of ω-transaminase in organic chemistry with a focus on the production of active pharmaceutical ingredients (APIs).

• Journal of the Korean Ceramic Society
• /
• v.41 no.6
• /
• pp.425-429
• /
• 2004

[DEACOOH]-Montmorillonite intercalations complex obtained from Na-Montmorillonite and 10-Carboxy-n-decyldimethylethylammonium bromide (organic cation) was reacted with the monomer ($\varepsilon$-caprolactone) to achieve the [DEACOOH]-$\varepsilon$-caprolactone-Montmorillonite intercalations complex. From this intercalations complex Montmorillonite/Polycaprolactone nanocomposites in which montmorillonite (inorganic polymer) is chemically linked with the polycaprolactone (organic polymer) were formed at 240$^{\circ}C$ by three different methods such as in stoichiometric amounts between monomer and organic cation, in excess of only the monomer and in excess of both organic cation and monomer. The products obtained after polymerization were analyzed with X-ray diffractometer and TEM.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.119.2-119.2
• /
• 2011

Dye-sensitized solar cells (DSSC) are currently attracting wide spread academic and commercial interest for the conversion of sunlight into electricity because of their easy manufacturing process and high efficiency. The solar energy conversion efficiencies of DSSC are strongly dependent on dye molecules adsorbed on the TiO2 surface which used for photosensitization of sun light, since an excited state of dye could inject an electron into the conduction band of semiconductor. We have developed novel organic dyes which have phenothiazine moieties as an electron donor in their charge-transfer chromophore for application of DSSCs. We had synthesized a series of phenothiazine derivatives which have different wave length absorbing chromophore in the molecule with high molar extinction coefficient. The photovoltaic performance of DSSC composed of organic chromophores with broad wavelength absorption property were measured and evaluated by comparison with that of pristine ruthenium dye.

• Natural Product Sciences
• /
• v.4 no.2
• /
• pp.78-83
• /
• 1998

Chemical investigation on a sample of the needles of Himalayan Taxus baccata has resulted in the isolation of several taxoids including taxol (1) 10-deacetyl-baccatin III (2) and 2-deacetoxytaxinine J (3) along with different lignans (6 and 7) and simple phenolics (8, 9, 10, 11 and 12). The occurrence of 4-(4'-hydroxyphenyl)-butane-2-one and 4-(4'-hydroxyphenyl)-trans-but 3-ene-2-one (8) in Taxus species is reported for the first time. The $^{13}C-NMR$ spectral data of two rearranged taxiod constituents, brevifoliol (4) and 13-decinnamoyltaxchinin B (5) are presented. The acid-catalyzed decomposition of taxol has been discussed. The synthesis of other two constituents, rhododendrol (10) and hibalactone (7) has been described.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.563-563
• /
• 2012

We report a one-step fabrication of single-crystal organic nanowire arrays on substrates using a new direct printing method (liquid-bridge-mediated nanotransfer moulding, LB-nTM), which can simultaneously enable the synthesis, alignment and patterning of the nanowires using molecular ink solutions. Two- or three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area with a successive process. The position of the nanowires can be aligned easily on complex structures because the mold is movable on substrates before drying the polar liquid layer, which acts as an adhesive lubricant. This efficient manufacturing method can produce a wide range of optoelectronic devices and integrated circuits with single-crystal organic nanowires.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.64.1-64.1
• /
• 2012

Next generation displays such as high performance LCD, AMOLED, flexible display and transparent display require specific TFT back-planes. For high performance TFT back-planes, low temperature poly silicon (LTPS), and metal-oxide semiconductors are studied. Flexible TFT backplanes require low temperature processible organic semiconductors. Not only development of active semiconducting materials but also design and synthesis of semiconductor corresponding gate dielectric materials are important issues in those display back-planes. In this study, we investigate the high heat resistant polymeric gate dielectric materials for organic TFT and inorganic TFT with good insulating properties and processing chemical resistance. We also controlled and optimized surface energy and morphology of gate dielectric layers for direct printing process with solution processible organic and inorganic semiconductors.

• Macromolecular Research
• /
• v.15 no.2
• /
• pp.147-153
• /
• 2007

Hyperbranched polysiloxysilanes (HBPSs), with a variety of terminal functional groups (vinyl, epoxy, carboxyl and hydroxyl), were synthesized by the self-polymerization of an $AB_3$ type monomer of tris(dimethylvinylsiloxy) silane, with subsequent end-functionalizations, such as epoxidation and radical addition reaction, respectively. The ratio of the $\alpha-and$ $\beta-addition$ linkages in the HBPS polymerized by hydrosilylation of the $AB_3$ monomer was found to be approximately 1 to 3. The thermal stability and solubility were affected by the terminal functional groups.