• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3211-3217
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• 2013

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of three D-${\pi}$-A-type organic dyes (C1-1, D5 and TH208) containing identical ${\pi}$-spacers and electron acceptors, but different aromatic amine electron-donating groups (tetrahydroquinoline, triphenylamine and phenothiazine). The coplanar geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating ability of tetrahydroquinoline is stronger than those of triphenylamine and phenothiazine. The computed orbital energy levels of these dyes confirm that the electrons could be injected from the excited dyes to the semiconductor conduction band and the oxidized dyes could be reduced effectively by electrolyte. The TD-DFT results show that the CAM-B3LYP/6-31+G(d, p) is suitable for calculating the absorption spectra. The first absorption band for these dyes is assigned to the HOMO${\rightarrow}$LUMO and HOMO-1${\rightarrow}$LUMO transitions.

• Nano
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• v.13 no.11
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• pp.1850132.1-1850132.14
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• 2018

The direct synthesis of metal-organic frameworks (MOFs) with acidic and basic active sites is challenging due to the introduction of functional groups by post-functionalization method often jeopardize the framework integrity. Herein, we report the direct synthesis of acid-base bifunctional MOFs with tuning acid-base strength. Employing modulated hydrothermal (MHT) approach, microporous MOFs named $UiO-66-NH_2$ was prepared. Through the ring-opening reaction of 1,3-propanesultone with amino group, $UiO-66-NH_2-SO_3H-type$ catalysts can be obtained. The synthesized catalysts were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-HMF conversion. Results revealed the acid-base bi-functional catalyst possessed high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of acid-base bi-functional MOFs for their potential use in catalysis field.

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.911-915
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• 2003

Two liquid chromatographic chiral stationary phases (CSPs) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid were successfully applied in the resolution of racemic tocainide and its analogues. In the resolution of tocainide, especially, the CSP containing N-CH₃ amide tethering groups was quite effective, showing clear baseline resolution (RS: 2.66) with reasonable enantioselectivity ( a: 1.25). Consequently, the CSP containing N-CH₃ amide tethering groups is expected to be useful to monitor the enantiomeric composition of tocainide in clinical samples. In addition, the chromatographic behaviors for the resolution of tocainide and its analogues on the two CSPs were found controllable by varying the content and the type of organic and acidic modifiers in aqueous mobile phase.

• Bulletin of the Korean Chemical Society
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• v.20 no.7
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• pp.801-804
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• 1999

Thermal and photoinduced silylallylation reactions of organic halides with 3-stannyl-2-(silylmethyl)propene are explored. Silylallylations occur in moderate to high yields, producing various functionalized allylsilane products in which halide carbon is bonded to the terminal alkenic carbon of allylsilane with the removal of tributyltin group. The reactions, which tolerate functional groups such as carbonyl, ester, nitrile, acetal, and ketal, hold synthetic potential for the construction of functionalized allylsilanes.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.97-98
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• 2006

After general introduction for hyperbranched polymers, hyperbranched polysiloxysilanes (HBPS) were introduced as new functional polymers. Vinyl terminated HBPS was synthesized starting from AB2 type monomer by hydrosilylation reaction. Vinyl group can be converted various functional groups such as carboxylic acid and alcohol. HBPS had strong interaction to inorganic surface. As an example of this phenomenon, silica gel bead for HPLC was modified with thermo sensitive polymers. The resulting bead was successfully applied to Green Chronatography.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.330-330
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• 2009

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.416-421
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• 1995

The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0 $^{\circ}C)$ in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2705-2710
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• 2011

Four MOFs functionalized with 1-Me, 1-Pr, 1-Ph, and 1-$PhCF_3$ were prepared through post-synthetic modifications of a metal-organic framework (MOF), UMCM-1-$NH_2$ (1) with acetic, butyric, benzoic, and 4-(trifluoromethyl)benzoic anhydrides, respectively. Methane adsorption measurements between 253 and 298 K at pressures up to 1 bar indicated that both 1-Ph and 1-$PhCF_3$ adsorbed more $CH_4$ than the parent MOF, 1. All the functionalized MOFs adsorbed more $CO_2$ than 1 under conditions similar to the $CH_4$ test. The introduction of functional groups promoted adsorption of both $CH_4$ and $CO_2$ despite significantly reducing Brunauer-Emmet-Teller (BET) surface area: 4170 (1), 3550 (1-Me), 2900 (1-Pr), 3680 (1-Ph), and 3520 $m^2/g$ (1-$PhCF_3$). Electron-withdrawing aromatic groups (1-Ph, 1-$PhCF_3$) more effectively enhanced $CO_2$ adsorption than electron-donating alkyl groups (1-Me, 1-Pr). In particular, 1-Ph adsorbed 23% more $CO_2$ at 298 K and 50% more at 253 K than 1.

• Journal of Korean Physical Therapy Science
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• v.6 no.4
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• pp.179-185
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• 1999

We know that social psychologic factors important to make a decision on characteristic of back pain and prognosis. These facters have difficult to diagnosis of back pain and being protract the treatment session and which bring about a social problem caused the impairment compensation. Clinically, twenty low back pain patients, 8 organic pain group and 12 functional pain group have completed the MMPI(Minnesota Multiphasic Personality Inventory) and the results were as follows: l)Mean MMPI T-score of Hypochondriasis was 56.60(12.39, that of Depression was 57.95(7.71, and that of Hysteria was 57.50(7.15. and those of other scales were within normal range near to 50. 2)there was no significant difference between male and female groups on MMPI scales 3)The MMPI T-score of organic group was significantly higher than that of functional group on Hypochondriasis and Hysteria scale.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.78-83
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• 2001

In this work, the surface of inorganic fillers were modified with some functional groups such as stearic acid, aliphatic long chain, vinylsilane and aminosilane to control the interaction between inorganic fillers and polymer matrix. Ethylene-vinyl acetate copolymers (EVA) with various amount of vinyl-acetate content and copolyether-ester elastomer were used as polymer matrix. The addition of inorganic fillers increases flame retardancy, but results in steep drop of electrical and mechanical properties, which may be caused by the defect in the interface between organic/inorganic hybrid composites. The hybrid composites are found to show better mechanical properties and higher volume resistivities as inorganic fillers are well dispersed and have good adhesion with polymer matrix. Also, the most effective type of functional group coated on fillers depends on the chemical structure of polymer.