• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.90-92
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• 2001

• 대한화학회지
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• 제39권5호
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• pp.414-420
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• 1995

디브로모알칸, AgF 및 tetrabutylammoniumbromide(TBABr)를 acetonitrile 용매하에서 $82^{\circ}C$에서 20분간 반응시켜 19~55%의 수율로 $\alpha$-브로모-$\omega$-플르오르알칸을 합성하였다. 반응 조건은 가스 크로마토그라피를 이용하여 조절하였으며, 반응 생성물인 $\alpha$-브로모-$\omega$-플르오르알칸, 디플르오로알칸, 플르오로알켄 및 브로모알켄을 1^H$ NMR 및 $19^F$ NMR로 확인하였다.

• 한국자기공명학회논문지
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• 제23권1호
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• pp.1-5
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• 2019

$^{19}F$ NMR experiments were carried out to observe the change of the characteristics of the PVdF binder which is an auxiliary material of the lithium ion battery. PVdF has various crystalline or amorphous phases by thermal treatment. A mixture of cathode and auxiliary materials including PVdF was coated on aluminum foil as an electron collector and then subjected to thermal treatment at various temperatures. The overlapped $^{19}F$ NMR signals obtained from the various phases were separately convoluted into the respective phases, and it was found that there was a relative ratio change of these phases. In addition, the crystal and amorphous phase of PVdF was changed during the vacuum drying, which is the last step of the actual electrode manufacturing. It was observed that the relative amount of amorphous phase, which may affect the flexibility of the electrode or the wettability of the electrolyte, abruptly changes after a certain temperature.

• BMB Reports
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• 제31권1호
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• pp.44-47
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• 1998

Asymmetry amongst nucleotide binding sites of Escherichia coli $F_1$-ATPase was examined using $^{19}F$ NMR signal from fluorinated analogs of adenine nucleotides bound to nucleotide binding sites. ADP-$CF_2-{PO_3}^{2-}$ showed no inhibitory effect to $F_1$-ATPase. But ADP-CHF-${PO_3}^{2-}$ (racemic mixture) showed competitive inhibition of $F_1$-ATPase with $K_i$ of $60\;{\mu}m$. ADP-CHF-${PO_3}^{2-}$ shows only negligible binding to $EF_1$ in the absence of $Mg^2+$. With the addition of $Mg^2+$ to the medium, the $^{19}F$ resonance of free ADP-CHF-${PO_3}^{2-}$ disappeared and the new broad resonances appeared. Appearance of more than two new asymmetric resonances following the binding of ADP-CHF-${PO_3}^{2-}$ to $EF_1$ may indicate that at least one of the isomers showed split resonances. This may suggest that the region between ${\alpha}$-and ${\beta}$-phosphate of ADP-CHF-${PO_3}^{2-}$ which is bound to catalytic sites is experiencing a different environment at different sites.

• 대한화학회지
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• 제41권9호
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• pp.495-501
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• 1997

• 대한화학회지
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• 제29권3호
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• pp.213-219
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• 1985

고정된 사이크로 프로판환을 가진 양이온계에서 구조적 변화에 따른 상대적 안정도를 불소 19-핵자기공명분광기로 분석 검토했다. 이를 위해 8-파라-불화벤젠트리사이크로 옥탄 양이온과 9-파라불화벤젠 트리사이크로 노난 및 10-파라불화벤젠 트리사이크로데칸 양이온을 해당알코올과 불화황산과의 반응에서 얻었다. 풀루오르 19-NMR 스펙트럼에서 얻어진 결론은 사이크로프로판환이 양이온 탄소의 궤도와 ${\sigma}$ 컨쥬게이션을 위해 대칭적이며 바이섹트 구조의 유지가 하전의 안정화에 매우 중요한 요인인 반면, 사이크로 프로판기의 면과 양하전을 띈 탄소와 연결되는 결합각도(${\theta}$)의 변화는 하전의 안정화에 영향이 없음을 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제19권3호
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• pp.379-383
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• 1998

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.305-305
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• 2006

The molecular structure and dynamics of inclusion compounds (ICs) consisting of n-perfluoroalkane (PFA) guests and ${\Box}-cyclodextrin$ (${\Box}-CD$) host were investigated using $^{19}F$ magic angle spinning (MAS) and $^{1}H{\to}^{19}F$ cross polarization (CP) / MAS NMR spectroscopy with the aid of thermal analyses, FT-IR spectroscopy, X-ray diffraction, and $^{1}H{\to}^{19}F$ CP/MAS technique revealed that $C_{9}F_{20}$ molecules included in ${\Box}-CD$ undergo vigorous molecular motion and partly come out of the ${\Box}-CD$ channel above $80^{\circ}C$. In case of $C_{20}F_{42}/{\Box}-CD$, an exothermic peak is observed by differential scanning calorimetry (DSC) at ca. $40^{\circ}C$ which suggests that ${\Box}-CD$ molecules become mobile and commence rearrangements that form more ordered structures at higher temperatures.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2345-2350
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• 2011

Variable temperature high-resolution $^{19}F$ magic angle spinning (MAS) solid-state NMR spectroscopy was used to characterize fluorocarbon (FKM) rubbers. The high-resolution spectra of copolymers made from two monomers, vinylidene fluoride and hexafluoropropene, and terpolymers composed of vinylidene fluoride, hexafluoropropene, and tetrafluoroethylene, were obtained using MAS speeds of up to 18 kHz combined with high temperatures of up to 200 $^{\circ}C$ at a magnetic field strength of 9.4 Tesla. From these high resolution solid-state NMR spectra, we were able to assign the spectral peaks and differentiate the copolymer FKM from the terpolymer FKM. We also determined quantitatively the monomer compositions of each FKM rubber.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.981-985
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• 2003

Fluorine-19 NMR solution measurements have been made for various phenyl-fluorinated iron porphyrin complexes. Large chemical shifts for phenyl fluorine signals of iron(III) and iron(II) are observed, and these signals are sensitive to electronic structure. The chemical shift differences in ortho-phenyl fluorine signals between high-spin ferric and low-spin ferric tetrakis(pentafluorophenyl)porphyrins are approximately 40 ppm, whereas the differences are approximately 7 ppm between high- and low-spin states of ferrous tetrakis(pentafluorophenyl)porphyrin complexes. Analysis of fluorine-19 isotropic shifts for the iron(III) tetrakis(pentafluorophenyl) porphyrin using fluorine-19 NMR indicates there is a sizable contact contribution at the ortho-phenyl fluorine ring position. Large phenyl fluorine-19 NMR chemical shift values, which are sensitive to the oxidation and spin states, can be utilized for identification of the solution electronic structures of iron(III) and iron(II) porphyrin complexes.