• Korean Journal of Crystallography
• /
• v.9 no.1
• /
• pp.1-5
• /
• 1998

The complex[Cu(L)I2, 2H2O(1) (L:3,14-Dimethyl-2,6,13,17-tetraazatricyclo [14,4,01.18, 07.12]docosane) has been prepared and structurally characterized. The complex (1) crystallizes in the triclinic system, space group P1, a=8.400(1)Å, b=8.986(3) Å, c=9.156(1) Å, α=82.42(1)˚, β=73.61(1)˚ λ=81.04(2)˚, Z=1, R for 1926 observed reflections of [F0>40(F0)], measured at 288K, was 0.042. The tetracoordination around Cu atom of complex(1) is square plane and the average bond distance of Cu-N is 2.029 (11) Å. Both six-membered chelate rings adopts a chair conformation and the five-membered ring are gauche with the sec-NH centers having the RRSS configuration.

• Analytical Science and Technology
• /
• v.12 no.3
• /
• pp.230-234
• /
• 1999

Barium titanyl oxalates (BTO) has been homogeneously prepared by thermal decomposition of dimethyl oxalate (DMO) in hydrochloric solution containing $Ba^{2+}$ and $Ti^{4+}$. Particles of BTO settled on the bottom of the beaker were collected at the aging time of 120 min using hydroxy propyl cellulose (HPC) as a dispersant. The reaction temperature, the concentration ratio of $[DMO]_0/([Ba^{2+}]_0+[Ti^{4+}]_0)$ and the existence of HPC were found to influence on morphologies of BTO, chemical yields and characteristics of barium titanates formed from their precursors.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.8
• /
• pp.2158-2162
• /
• 2010

Studies on the molecular construction and structures of $M(NO_3)_2$ (M = Cu(II), Ni(II)) complexes with 1,2-bis(dimethyl-3-pyridylsilyl)ethane (L) have been carried out. Formation of each molecular skeleton appears to be primarily associated with a suitable combination of bidentate N-donors of L and coordinating nature of octahedral metal(II) ions: [$Cu(NO_3)_2(L)_2$] yields a 2-dimensional sheet structure consisting of 44-membered $Cu_4L_4$ skeleton whereas $[Ni(L)_2(H_2O)_2](NO_3)_2$ produces an interpenetrated 3-dimensional structure consisting of 66-membered cyclohexanoid ($M_6L_6$) skeleton. The Cu(II) ion prefers nitrate whereas the Ni(II) ion prefers water molecules as the fifth and the sixth ligands.

• Mycobiology
• /
• v.49 no.6
• /
• pp.604-606
• /
• 2021

In our ongoing search for new secondary metabolites from fungal strains, one novel compound (1) and nine known compounds (2-10) were isolated from the EtOAc-soluble layer of the culture broth of Panus rudis. The culture broth of P. rudis was extracted in acetone and fractionated by solvent partition; column chromatography using silica gel, Sephadex LH-20, and Sephadex G-10; MPLC; and HPLC. The structures of isolated compounds were elucidated by one- and two-dimensional NMR and LC-ESI-mass measurements. One new compound, panepoxydiol (1), and nine known compounds, (E)-3-(3-hydroxy-3-methylbut-1-en-1-yl)-7-oxabicyclo[4.1.0]hept-3-ene-2,5-diol (2), isopanepoxydone (3), neopanepoxydone (4), panepoxydone (5), panepophenanthrin (6), 4-hydroxy-2,2-dimethyl-6-methoxychromane (7), 6-hydroxy-2,2-dimethyl-3-chromen (8), 2,2-dimethyl-6-methoxychroman-4-one (9), 3,4-dihydroxy-2,2-dimethyl-6-methoxychromane (10), were isolated from the culture broth of P. rudis. This is the first report of isolation of a new compound panepoxydiol (1) and nine other chemical constituents (2-5, 7-10) from the culture broth of P. rudis.

• Analytical Science and Technology
• /
• v.7 no.3
• /
• pp.321-327
• /
• 1994

The mild thermal decomposition of 7, 7-dimethyl-1, 2, 3, 4, 5-pentaphenyl-7-silanorbornadiene with excess methyl alcohol proceeds to give 1-methoxydimethylsilyl-1, 2, 3, 4, 6-pentaphenylcyclohexa-2, 5-diene which is colorless needle crystal. The cophotolysis of the solution of 7-silanorbornadiene in the excess ethyl alcohol proceeds with loss of silylenes to give ethoxydimethylsilane which is insertion reaction product of silylene with O-H bond of ethyl alcohol. According to above results, it is presumed that the mechanism of photochemical decomposition and that of mild thermochemical decomposition of 7-silanorbornadiene are different.

• Polymer(Korea)
• /
• v.29 no.2
• /
• pp.161-165
• /
• 2005

$\alpha,\omega-Vinyl$ poly(dimethyl-methylphenyl) siloxane propelymer (VPMPS ) was prepared by the equilibrium polymerization of octamethylcyclotetrasiloxane $(D_4)$, 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane $(D_3^{MePh})$, and 1,1,3,3-tetramethyl-1,3-divinylsiloxane (MVS) as end-blocker. And also, $\alpha,\omega-hydrogen$ poly(dimethyl-methyltrifluoropropyl)siloxane prepolymer (HPDMFS) was prepared from $D_4$, 1,3,5-trimethyl-1,3.5-trifluoropropylcyclotrisiloxane $(D_3^{MeF3P})$, and 1,1,3,3-tetramethyldisiloxane. Poly(organosiloxane) rubber composite containing high thermal conductive filler was prepared by compounding VPMPS, HPDMFS, spherical alumina, and catalyst in high speed dissolver. The crosslinking density of poly (organosiloxane) composite was measured by oscillation rheometer. Poly(organosiloxane) composites of TC-POXR-2 and TC-POXR-4 prepared by controlling average diameters of thermal conductive filler, spherical alumina according to Horsfield's packing model were shown to 1.13 W/mK for TC-POXR-2 and 1.19 W/mK for TC-POXR-4.

• Applied Chemistry for Engineering
• /
• v.22 no.1
• /
• pp.15-20
• /
• 2011

Poly[2,3-dimethyl-5,8-dithiophene-2-yl-quinoxaline-alt-9,9-dihexyl-9H-fluorene] (PFTQT) and poly[2,3-dimethyl-5,8-dithiophen-2-yl-quinoxaline-alt-10-hexyl-10H-phenothiazine (PPTTQT) based on 2,3-dimethyl-5,8-dithiophen-2-yl-quinoxaline weresynthesized by Suzuki coupling reaction. All polymers were soluble in common organic solvents such as chloroform, chlorobenzene, o-dichlorobenzene, tetrahydrofuran (THF) and toluene. The maximum absorption wavelength and band gap of PFTQT were 440 nm and 2.30 eV, and PPTTQT were 445 nm and 2.23 eV, respectively. The HOMO and LUMO energy level of PFTQT were -6.05 and -3.75 eV, and PPTTQT were -5,89 and -3.66 eV, respectively. The organic photovoltaic devices based on the blend of polymer and PCBM (1 : 2 by weight ratio) were fabricated. Efficiencies of devices were 0.24% (PFTQT) and 0.16% (PPTTQT), respectively. The short circuit current density ($J_{sc}$), fill factor (FF), and open circuit voltage ($V_{oc}$) of the device with PFTQT were $0.97mA/cm^2$, 29% and 0.86 V, and the device based on PPTTQT were $0.80mA/cm^2$, 28% and 0.71 V, 31% and 0.71 V, respectively, under air mass (AM) 1.5 G and 1 sun condition ($100mA/cm^2$).

• Journal of the Korean Chemical Society
• /
• v.33 no.6
• /
• pp.607-613
• /
• 1989

The chemical equilibria of Ni(II)-tetraamine (tetraamine = 2,12-dimethyl-3,7,11,17-tetraazabicyclo-11,3,1-heptadeca-1(17),2,11,13,15-pentaene) complex ion in water, acetonitrile, acetone and nitromethane were investigated using spectrophotometric method, respectively. The equilibria between low-spin ($D_{4h}$) and high-spin ($O_h$) structures of Ni-tetraamine complex ion were presented in water, acetonitrile and acetone, but not in nitromethane. The eqilibrium constants, the reaction enthalpies and the reaction entropies were determined from analysis of the temperature dependence of the electronic spectra. The formation of the triplet species ($O_h$) was found to be exothermic. The solvent and electrolyte effects on the equilibrium constants could be explained by the dielectric constants of solvents and the reaction entropies.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.10
• /
• pp.703-709
• /
• 2013

Ozonation was performed under various experimental conditions that $Al_2O_3$ catalysts dosage and temperature for removal of DMP in laboratory scale batch reactor. Flow rate of ozone $1.0Lmin^{-1}$ and ozone concentration of $300{\pm}10mgL^{-1}$ were maintained constantly, and the pH, $COD_{Cr}$ and TOC was measured in 10 min intervals during the 60 min at oxidation processes. As a result, the presence of the $Al_2O_3$ than only ozonation increased the removal efficiency of both $COD_{Cr}$ and TOC in solution. The pseudo first-order rate constants for the elimination of $COD_{Cr}$ and TOC were $3.65{\times}10^{-4}sec^{-1}$, $2.52{\times}10^{-4}sec^{-1}$, and activation energy was $0.75kcal{\cdot}mol^{-1}$ and $0.70kcal{\cdot}mol^{-1}$ at $20^{\circ}C$, respectively.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.8
• /
• pp.1103-1105
• /
• 2002

H-ZSM-5 and γ-alumina were treated with formaldehyde and sodium carbonate. The treatment increased the amounts of weak acid sites, removing strong acid sites. The maximum temperature of weak acid sites in their ammonia TPD spectra shifted in the direction of high temperature. The modified H-ZSM-5 and g-alumina were mixed with the methanol synthesis catalyst to perform dimethyl ether synthesis from syn-gas. The modified catalysts showed better selectivity to dimethyl ether, minimizing the reforming reaction to carbon dioxide. The maximum yield of 53.3% to dimethyl ether was achieved under the reaction conditions of 54.4 atm, 523 K, and the feed rate of 4500 Lhr-1 .gcat-1.