• Elastomers and Composites
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• v.19 no.1
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• pp.32-45
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• 1984

• YAKHAK HOEJI
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• v.33 no.3
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• pp.203-205
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• 1989

A method is presented for calculating the $^{13}C$ chemical shifts produced in liquid solution by referenced relative to RF frequency. The method is useful to get the real variations of chemical shifts in magnetic field by eliminating the affects of the variation of a reference substance.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.61-64
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• 2000

$^{11}$B NMR measurements have been performed to investigate local electronic structure and 4f spin dynamics for TbNi$_2$B$_2$C single crystal. $^{11}$B NMR spectra show three resonance peaks due to the quadrupolar interaction. Shift and linewidth are huge and strongly temperature-dependent. In addition, both are proportional to magnetic susceptibility, indicating that the hyperfine field at the boron site originates from the 4f spins of Tb. $^{11}$B NMR shift and relaxation rates show high anisotropy for field parallel and perpendicular to the c-axis. Anisotropy of the shift and the relaxation rates suggests that the hyperfine field perpendicular to the c-axis is larger.

• Analytical Science and Technology
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• v.14 no.1
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• pp.1-7
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• 2001

6,6-Dichlorobicyclo[3, 1, 0]hexane-3carboxylic acid was synthesized by dichlorocarbene addition into 3-cyclopentenecarboxylic acid using BTEA.Cl as phase transfer catalyst. $^1H$ NMR $^{13}C$ NMR data analyst showed that this compound had boat-like conformation and carboxyl group existed as trans form.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.1
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• pp.29-35
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• 2015

The microscopic dynamics of $CsH_2PO_4$, with two distinct hydrogen bond lengths, are studied by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. The proton dynamics of the two crystallographically inequivalent hydrogen sites were discussed in terms of the $^1H$ NMR and $^1H$ MAS NMR spectra. Although the hydrogen bonds have two inequivalent sites, H(1) and H(2), distinct proton dynamics for the two sites were not found. Further, the $^{133}Cs$ spectrum is more or less continuous near $T_{C1}$ (=153 K). Finally, the phase transition mechanism of $T_{C1}$ in $CsH_2PO_4$ is related to the ordering of protons.

• YAKHAK HOEJI
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• v.32 no.3
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• pp.164-169
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• 1988

$^{13}C$ NMR chemical shifts for 18 ${\alpha}-susbstituted$ toluenes at high dilution in $CCl_4$ solution have been determined. Substituents are as follows: H, Me, Et, n-Pr, iso-Pr, Ph, F, Cl, Br, $NH_2$, NHMe, $NMe_2$, OH, OMe, OCOMe, $CO_2Me$, $CO_2Et$, CN. Those chemical shifts of the methylene carbon of the toluene and the ${\alpha}-carbon$ of the n-butane systems are correlated well. (r=.975, slope=.962)

• Journal of Ginseng Research
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• v.21 no.2
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• pp.104-108
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• 1997

(20S)-ginsenoside $Rs_3$ and its isomers were chemically prepared from diol ginseng saponins by partial acid hydrolysis and acetylation. The characteristics of $^{1}H-NMR$ and $^{13}-NMR$ data were compared with each other and fully assigned.

• Progress in Superconductivity
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• v.12 no.1
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• pp.51-56
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• 2010

$^{13}C$ NMR (nuclear magnetic resonance) measurements have been performed to investigate the local electronic structure of a superconducting graphite intercalation compound $CaC_6$ ($T_c$ = 11.4 K). A large number of single crystals were stacked and sealed in a quartz tube for naturally abundant $^{13}C$ NMR. The spectrum, Knight shift, linewidth, and spin-lattice relaxation time $T_1$ were measured in the normal state as a function of temperature down to 80 K at 8.0 T perpendicular to the c-axis. The $^{13}C$ NMR spectrum shows a single narrow peak with a very small Knight shift. The Knight shift and the linewidth of the $^{13}C$ NMR are temperature-independent around, respectively, +0.012% and 1.2 kHz. The spin-lattice relaxation rate, $1/T_1$, is proportional to temperature confirming a Korringa behavior as for non-magnetic metals. The Korringa product is measured to be $T_1T\;=\;210\;s{\cdot}K$. From this value, the Korringa ratio is deduced to be $\xi$ = 0.73, close to unity, which suggests that the independent-electron description works well for $CaC_6$, without complications arising from correlation and many-body effects.

• Analytical Science and Technology
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• v.9 no.2
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• pp.168-178
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• 1996

Molecular structures of petroleum fractions(diesel fuel, bunker-C oil, lubricant base stocks) have been analyzed and compared in terms of the compositions (aromatics, naphtherucs, paraffinics), aromatics(benzene-nuclear and bonded alkyl groups), C2(methylene) carbon atoms % $C_{\alpha}$ and $C_{\beta}$ carbon stom % in alkyl groups and paraffins(branched and normal) by near-infrared and $^{13}C$-NMR spectroscopy.

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.356-360
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• 2007

5,7-Diaryl-3,4,6-trihydronaphthalen-2-ones have been synthesized from 3,5-diaryl-cyclohex-2-en-1- ones and methyl vinyl ketone in the presence of sodium ethoxide. The products were characterized by IR, UV-Visible, 1H-NMR, 13C-NMR and mass spectral techniques. To confirm 1H and 13C signals, HSQC spectrum was recorded and analyzed.