• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.594-598
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• 2005

Treatment of a solution of $CuCl_2$ in dimethyl phosphate (DMP) with DMSO under nitrogen atmosphere afforded to a light blue fluorescence powder. Slow evaporation of $H_2O$-DMSO solution of this powder resulted in blue-sky crystals of a new polymeric Cu(II) complex, with a unit cell composed of $Cu_2(DMP)_4$(DMSO), (1). The crystal and molecular structure of the complex acquired crystallographically. Compound (1) crystallizes in the monoclinic space group $P2_1$/n with a = 12.8920(11) $\AA$, b = 13.1966(11) $\AA$, c = 14.7926(13) $\AA$, $\alpha$ = 90$^{\circ}$, $\beta$ = 98.943(2)$^{\circ}$, $\gamma$ = 90$^{\circ}$, V= 2486.1(4) ${\AA}^3$, and Z = 4. A square pyramidal environment for the metal center was established by coordination of oxygen atoms of four bridging DMP ligands in the basal positions and binding a tri-centered oxygen atom of DMSO in the apical disposition of Cu(II). The sixth position was also affected by a weak interaction with the sulfur atom of another DMSO. The phosphorous atom in the bridging DMP was arranged in a deformed tetrahedron with (gg) conformation for methyl esters with $C_{2v}$ symmetry.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.191-196
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• 2008

Kinetic studies of the reactions of a-bromoacetanilides [YC6H4NHC(=O)CH2Br] with substituted benzylamines (XC6H4CH2NH2) have been carried out in dimethyl sulfoxide at 35.0 oC. The Hammett plots for substituent (Y) variations in the substrate (log kN vs. sY) are biphasic concave upwards/downwards with breaks at Y = 4-Cl (sY = 0.23). The Hammett coefficients rY and the cross-interaction constant rXY (= +0.16) are positive for sY 0.23, while the rY values are positive/negative [rY > 0 for X = (4-MeO and 4-Me) and rY < 0 for X = (H, 4-Cl and 3-Cl)] and the rXY (= -1.51) value is negative for sY ³ 0.23. Based on these and other results, the benzylaminolyses of a-bromoacetanilides are proposed to proceed through rate-limiting expulsion of the bromide leaving group from a zwitterionic tetrahedral intermediate, T, with a bridged transition state for s Y 0.23, while the reaction proceeds through concerted mechanism with an enolate-like TS in which the nucleophile attacks the a-carbon for s Y ³ 0.23.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1689-1696
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• 2020

In this study, we developed a fiber-optic humidity sensor (FOHS) system for the monitoring and detection of coolant leakage in nuclear power plants. The FOHS system includes an FOHS, a spectrometer, a halogen white-light source, and a Y-coupler. The FOHS is composed of a humidity-sensing material, a metal tube, a multi-mode plastic optical fiber, and a subminiature version A (SMA) fiber-optic connector. The humidity-sensing material is synthesized from a mixture of polyvinylidene fluoride (PVDF) in dimethyl sulfoxide (DMSO) and hydroxyethyl cellulose (HEC) in distilled water. We measured the optical intensity of the light signals reflected from the FOHS placed inside the humidity chamber with relative humidity (RH) variation from 40 to 95%. We found that the optical intensity of the sensing probe increased linearly with the RH. The reversibility and reproducibility of the FOHS were also evaluated.

• Carbon letters
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• v.13 no.3
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• pp.133-138
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• 2012

According to kinetic mechanisms, liquid phase polymerization and solid phase polymerization are different in acrylonitrile (AN) polymerization, and so the relationship between the contribution ratio and molecular weight distribution (MWD) was obtained through theoretic analysis. The precipitation homopolymerization of AN was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at $50{\sim}65^{\circ}C$ using ${\alpha}$,${\alpha}^{\prime}$-azobisisobutyronitrile as an initiator. The contribution ratio decreased and approached 0; the MWD also decreased and approached 2 with the increase of the $H_2O$/DMSO ratio from 10/90 to 90/10. The experimental data were found to coincide well with the theoretical equation derived from the mechanisms.

• Journal of Electrochemical Science and Technology
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• v.11 no.4
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• pp.361-367
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• 2020

Recently, layered nickel-rich cathode materials (NCM) have attracted considerable attention as advanced alternative cathode materials for use in lithium-ion batteries (LIBs). However, their inferior surface stability that gives rise to rapid fading of cycling performance is a significant drawback. This paper proposes a simple and convenient coating method that improves the surface stability of NCM using sulfate-based solvents that create artificial cathode-electrolyte interphases (CEI) on the NCM surface. SO_x-based artificial CEI layer is successfully coated on the surface of the NCM through a wet-coating process that uses dimethyl sulfone (DMS) and dimethyl sulfoxide (DMSO) as liquid precursors. It is found that the SO_x-based artificial CEI layer is well developed on the surface of NCM with a thickness of a few nanometers, and it does not degrade the layered structure of NCM. In cycling performance tests, cells with DMS- or DMSO-modified NCM811 cathodes exhibited improved specific capacity retention at room temperature as well as at high temperature (DMS-NCM811: 99.4%, DMSO-NCM811: 88.6%, and NCM811: 78.4%), as the SO_x-based artificial CEI layer effectively suppresses undesired surface reactions such as electrolyte decomposition.

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1140-1144
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• 2006

A macrocyclic ligand, N,N',N'-tribenzyl-2,11,20-triaza[3,3,3](2,6)pyridinophane (BAPP), was used to prepare an iron(II) complex as a nonheme model complex, $[(BAPP)Fe]^{+2}$ (1). X-ray crystallography of a colorless crystal of 1 revealed that BAPP acted as a pentadentate ligand due to geometrical strain for the formation of a six-coordinate iron(II) complex by BAPP. As a result, the iron center revealed a significantly distorted square pyramidal geometry similar to that found in the active site of taurine dioxygenase (tauD). In the reaction of 1 with PhIO, no intermediate was observed in the UV-visible region of spectrometer at low temperatures. Catalytic oxidations of triphenyl phosphine with PhIO at ${-40^{\circ}C}$ revealed that 1 was able to convert triphenyl phosphine to triphenyl phosphine oxide.23; SSOCHKThioanisole was also oxidized to the corresponding methylphenyl sulfoxide under the same conditions.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.738-743
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• 1992

${\alpha}-Arylhydrazonoacylazide(7) was synthesized starting from {\circo}-phenylenediamine(3) in four steps. The tautomeric behavior of {\alpha}-arylhydrazonoacylazide(7) between the hydrazone imine and diazenyl enamine forms in the dimethyl sulfoxide solution was investigated on the basis of the tautomer ratio determined by the ^1H-NMR spectral data. The 1-aryl-3-quinoxalinyl-1,2,4-triazol(8) was synthesized from {\alpha}-arylhydrazonoacylazide(7) by refluxing in benzene.$

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.103-103
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• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.104-104
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• 2002

This study was performed to find out the optimal larval stage among trochophore, D-shaped and umbo stage larvae and the desirable protective additive such as fructose, glucose, sucrose and trehalose with cryoprotectant for cryopreservation of surf clam, Spisula sachalinensis larvae. Dimethyl sulfoxide and ethylene glycol were used as cryoprotectant and each cryoprotectant was made to 2.0 M with previous protective additives. The larvae were immersed in the preparations waited for 15 minutes to reach equilibration, and then frozen in a program freezer (-35$^{\circ}C$) and liquid nitrogen (-196$^{\circ}C$). The freezing rate of 1.0$^{\circ}C$ /min. was used for cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). The survival rate of frozen-thawed larvae increased as larval developing and that of umbo stage larvae was the highest as 96.1 ${\pm}$ 1.0%. The presence of lower concentration of disaccharides as sucrose or trehalose significantly enhanced survival rate when mixed with cryoprotectants (P<0.05). The results of our study indicate that desirable developmental stages of larvae and protective additive for cryopreservation are the umbo stage larvae and 0.2 M sucrose, respectively.

• Journal of the Korean Ceramic Society
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• v.48 no.2
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• pp.200-204
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• 2011

Increase of surface area and decrease of band gap in $TiO_2$ semiconductors are significant to improve the efficiency of water splitting by photoelectrolysis. In this study $TiO_2$ nanotube arrays with ~7 um length and ~100 nm diameter were fabricated by an anodizing technique of titanium foils using DMSO (dimethyl sulfoxide)-based electrolytes. Then to control the band gap of the $TiO_2$ arrays, they were annealed at $550^{\circ}C$ for up to 180 min in $NH_3$ gas ambient. The samples annealed in $NH_3$ gas for 30 min and 60 min showed superior photo-conversion efficiency for water splitting under white and visible light. A $TiO_2$ nanotube annealed in $NH_3$ gas ambient for a period longer than 120 min showed 1 order higher leakage current. It is believed that the decrease of band gap and increase of conductivity in $TiO_2$ nanotube arrays due to $NH_3$ gas treatments result in the superior water-splitting performance.