• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.133-135
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• 2003

The washing effects on pretilt angle generation in a nematic liquid crystal (NLC), 4-n-pentyl-4’-cyanobiphenyl (5CB) on a rubbed polyimide (PI) surface with trifluoromethyl moiety have been successfully studied. The pretilt angle of 5CB is increased by the washing process on the rubbed PI surface. The surface tension on the rubbed PI surface increases with the rubbing strength RS and then saturated above RS=150 mm. The pretilt angle of 5CB for all washing processes on the rubbed PI surface decreases with the surface tension. We have found that the pretilt angle of 5CB on the rubbed PI surface may be attributed van der walls (VDW) dispersion interaction between the LC molecules and the polymer surfaces having trifluoromethyl moieties.

• Macromolecular Research
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• v.8 no.4
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• pp.165-171
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• 2000

Fluorinated polyimides with high thermal stability, low optical absorption loss in the optical communication wavelengths of 1.3 and 1.55㎛, and low birefringence and water absorption have been investigated for optical waveguide applications. These polyimides were prepared from 2,2-bis(3,4-dicar-boxyphenyl) hexafluoropropane dianhydride (6FDA) with 1,4-bis-(4-amino-2-trifluoromethyl-phenoxy) tetrafluorobenzene (ATPT) , 1,4-bis-(4-amino-2-trifluoromethyl-phenoxy) benzene (ATPB) , and 1,3-bis-(4-amino-2-trifluoromethyl-phenoxy ) 4,6-dichlorobenzene (ATPD ), respectively. The polyimides obtained had glass transition temperatures that ranged from 260 to 280$\^{C}$, and low water absorption less than 0.4% and low optical loss (> 0.2 dB/cm) at 1.3 and 1.55㎛. Birefringency values of polymer films ranged from 0.0041 to 0.0066.

• Bulletin of the Korean Chemical Society
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• v.11 no.4
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• pp.333-339
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• 1990

A series of new dimesogenic compounds whose mesogens are of aromatic ester or amide type having a trifluoromethyl $(CF_3)$ substituent at the para-position of each terminal phenolic rings were prepared and their liquid crystalline properties were studied by differential scanning calorimetry (DSC) and on a cross-polarizing microscope. The compounds have two identical mesogenic units bracketing a central decamethylene spacer. Trifluoromethyl group appears to favor the formation of smectic phases when it is attached to a phenoxy or anilide terminal. Its group efficiency for mesophase formation seems to be inferior to other common substituents. A thermodynamic analysis of the phase transitions was made and the results were explained in relation to the structures of the compounds.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.176-183
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• 1993

Photolysis experiments were conducted to investigate the stability of a new insecticide, [O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester: KH-502] under the various conditions. In the photolysis experiment, KH-502 was, after being added into the acetone or acetonitrile solution, irradiated under the sunlight or UV lamp $(300{\sim}350nm)$, where acetone or acetonitrile solution was varied with water and $O_2$contents and was treated with humic acid, rosebengal or tryptophan. Results for stability and degradation pattern of KH-502 from the above experiment can be summarized as follows: 1. The significant difference in KH-502 decomposition due to photolysis was shown for between KH-502s irradiated at $300{\sim}350$ nm and non-irradiated. KH-502 was photolyzed in the acetone by the sensitizing effect, but was stable in the acetonitrile. 2. The degradation pattern of KH-502 in the photolysis was different as compared to that in the thermal decomposition, and the decomposed products were O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphoric acid ester (KH-502 oxo form), O,S-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphorothiolate(S-ethyl KH-502), 1-Phenyl-3-trifluoromethyl-5-hydroxy pyrazole (PTMHP) and several unknown compounds. 3. Treatments of acetone or acetonitrile solution with humic acid, rosebengal or tryptophan revealed no-sensitizing effect on the photolysis of KH-502. Dissolved oxygen in the acetone played as a cosensitizer with acetone competitively to enhance the photolysis of KH-502. 4. Treatments of acetone with humic acid or paddy soil water collected from fields decreased the photolysis of KH-502.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.225-234
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• 1992

Thermal decomposition was conducted to investigate the influence of the various factors on stability of a new insecticide, [O, O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester : KH-502], in view of those informations applicable for industrial exploitation. In the thermal decomposition experiment, KH-502 was, after mixing with Fe, Cu and adjustment of moisture and pH conditions, subjected to three temperatures, 25, 50, and $100^{\circ}C$. Results for stability, and degradation pattern of KH-502 from the above experiment can be summarized as follows: 1. Main products of the thermal decomposition when this was conducted in the closed system were identified as following five compounds:O, O, O-Triethylthiophosphoric acid(TEPA), 1-Phenyl-3-trifluoromethyl-5-ethoxypyrazole(PTMEP), 1-Phenyl-2-ethyl-3-trifluoromethyl-5-hydroxypyrazole(PETMHP), O, O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphoric acid ester(KH-502 oxo form), O, S-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phospho rothiolate(S-ethyl KH-502). However, compounds such as oxo form and S-ethyl KH-502 were not identified when the thermal decomposition was proceeded in the open system. 2. KH-502 was stable at 25 and 50$^{\circ}C$, but it was decomposed at 100$^{\circ}C$ following the first-order kinetics at the early stages of decomposition. 3. Rate constants for the thermal decomposition of KH-502 at 100$^{\circ}C$ were in the orders of Cu powder addition 0.344>Cu plate addition 0.21>moisture addition 0.05>closed system=open system=iron addition=pH 5.5 adjustment 0.04>pH 8.5 adjustment 0.027 day$^{-1}$, representing KH-502 was decomposed fast at Cu powder treatment and slow at pH 8.5 adjustment. 4. Half-life for the thermal decomposition of KH-502 at 100$^{\circ}C$ was in the orders of Cu powder addition 2.02

• Bulletin of the Korean Chemical Society
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• v.9 no.4
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• pp.236-240
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• 1988

A thioamide, N-5-trifluoromethyl-6-methoxy-1-thionaphthoyl-N-m ethylglycine, undergoes trans${\rightleftharpoons}$cis photoisomerization around C-N bound in solution. Azulene quenching studies showed the photoisomerization to proceed via both singlet and triplet excited states.The total quantum yield of the trans${\rightarrow}$cis photoisomerization is about 0.26, 0.14 from the singlet excited state and 0.12 from the triplet excited state. Intersystem crossing and internal conversion quantum yields were calculated from sensitized photostationary state and a plausible mechanism is proposed.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.70-76
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• 1996

A series of the herbicidal pyridylsulfonyl areas, none substitutent, 1-(4,6-dimethoxypyrimidine-2-yl)-3-(2-pyridylsulfonyl) urea, 3 and 3-trifluoromethyl substitutent, 1-(4,6-dimethoxypyrimidine-2-yl)-3-(3-trifluoromethyl-2-pyridylsulfonyl) urea, 5(Flazasulfuron) were synthesizied and the rate of hydrolysis of their has been studied in 25%(v/v) aqueous dioxane at $45^{\circ}C$. From the results of solvent effect($m{\ll}1,\;n{\ll}3\;&\;{\mid}m{\mid}{\ll}{\mid}{\ell}{\mid}$), thermodynamic parameter (${\Delta}S^{\neq}=0.54{\sim}\;-2.19\;e.u.\;&\;{\Delta}H^{\neq}=0.025\;Kcal.mol.^{-1}$), hydrolysis product analysis, $pK_a$ constant(3: 4.9 & 5: lit.4.6) and the rate equation, a marked difference in the kinetics of the reaction of 3 and 5(Flazasulfuron) was observed. It may be concluded that the hydrolysis of 5 proceeds through the $A-S_N2Ar$ reaction via conjugate acid$(5H^+)$ below pH 7.0, whereas, above pH 9.0, the hydrolysis proceeds through irreversibly $(E_1)_{anion}$ and reversibly $(E_1CB)_R$ mechanism via conjugate base(CB), respectively. But in case of 5, $A-S_N2Ar,\;(E_1)anion\;and\;(E_1CB)_R$ mechanism involved Smile rearrangement. The mate of rearrangement of 5 to a 3-trifluoromethyl-2-pyridylpyrimidinyl urea(PPU) in acid and 3-trifluoromethyl-2-pyridyl-4.6-dimethoxypyridinyl amine (PPA) in base was increased about 3.5 times by the introduction of trifluoromethyl group in the 3-position on the 2-pyridyl ring. From the basis of these findings, a possible mechanism for the hydrolysis of 5 was proposed and discussed.

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.105-109
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• 2002

Synthetic method of a new benzoylphenylurea insecticide, DBI-3204 [1-(2,6-Difluorobenzoyl)-3-(3,5-bistrifluoromethyl-2-chlorophenyl) urea] was established for manufactural production; 2,6-Difluorobenzoylisocyanate was synthesized by the reaction of 2,6-difluorobenzamide with oxalylchloride in 95% yields, the reaction of 3,5-bis(trifluoromethyl)aniline with N-chlorosuccinimde gave 3,5-bis (trifluoromethyl)-2-chloroaniline in 92% yields, and DBI-3204 was got from 2,6-difluorobenzoylisocyanate and 3,5-bis(trifluoromethyl)-2-chloroaniline in 90% yields. All the process was simplified by using the same reaction solvent, carbontetrachloride.

• Transactions on Electrical and Electronic Materials
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• v.4 no.1
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• pp.21-23
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• 2003

The washing effects on pretilt angle generation in a nematic liquid crystal (NLC), 4-n-pentyl-4'-cyanobiphenyl (5CB) on a rubbed polyimide (PI) surface with trifluoromethyl moiety have been successfully studied. The pretilt angle of 5CB is increased by the washing process on the rubbed PI surface. The surface tension on the rubbed PI surface increases with the rubbing strength RS and then saturated above RS: 150 mm. The pretilt angle of 5CB for all washing processes on the rubbed PI surface decreases with the surface tension. We have found that the pretilt angle of 5CB on the rubbed PI surface may be attributed van der walls (VDW) dispersion interaction between the LC molecules and the polymer surfaces having trifluoromethyl moieties.

• Natural Product Sciences
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• v.23 no.4
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• pp.299-305
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• 2017

P-methoxycinnamic acid and 3,4,5-trimethoxycinnamic acid are the compounds found in Polygalae Radix, the root of Polygala tenuifolia Willdenow, and have been reported to have hepatoprotective and anti-neurodegenerative effects. On the other hand, there are no reports of their effects on gastric lesions. This study examined the inhibitory effects of cinnamic acids, including p-methoxycinnamic acid, 3,4,5-trimethoxycinnamic acid, and 8 compounds (cinnamic acid, 2-(trifluoromethyl) cinnamic acid, 3-(trifluoromethyl) cinnamic acid, trans-4-(trifluoromethyl) cinnamic acid, 4-(dimethylamino) cinnamic acid, 3,4-(methylenedioxy) cinnamic acid and 3,4-dihydroxycinnamic acid), which were selected based on their presence in medicinal herbs and molecular weight, against gastric lesions. Animal models were used to confirm the protective effects on acute gastritis caused by the administration of HCl/EtOH. Gastric acid inhibition was examined by an acid-neutralizing test and the proton pump ($H^+/K^+$-ATPase) inhibiting activity. In addition, antioxidant tests were performed and the gastric emptying rate was determined. The results showed that cinnamic acid, p-methoxycinnamic acid, and 3,4,5-trimethoxycinnamic acid had an inhibitory effect on gastric lesions.