• Journal of the Korean Chemical Society
• /
• v.36 no.2
• /
• pp.248-254
• /
• 1992

Bis(phosphine)ruthenium derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)_2(PR_3=PMe_3,\; PMe_2Ph,\;PEt_3,\;PMePh_2$, 1/2DPPE, 1/2DPPB) (2a${\sim}$2f) have been synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with excessive phosphine in ethanol. The reaction of complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2Cl\;with\;NaBH_4$ in ethanol gave the corresponding hydride complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2H (PR_3=PMe_3, PEt_3, PMePh_2$, 1/2 DPPE, 1/2DPPB) (3a${\sim}$3e). Chloride complexes (2a${\sim}$2f) and hydride complexes (3a${\sim}$3e) were isolated as crystals, which were characterized by IR, $^1H-NMR$ , and elemental analysis.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.10
• /
• pp.1050-1052
• /
• 1997

The complexes M(CO)4-1,2-(PPh2)2-1,2-C2B10H10 (M=Cr 2a, Mo 2b, W 2c) have been prepared in good yields from readily available bis-diphenylphosphino-o-carboranyl ligand, closo-1,2-(PPh2)2-1,2-C2B10H10 (1), by direct reaction with Group Ⅵ metal carbonyls. The infrared spectra of the complexes indicate that there is an octahedral disposition of chelate bis-diphenylphosphino-o-carboranyl ligand around the metal atom. The crystal structure of 2a was determined by X-ray diffraction. Complex 2a crystallizes in the monoclinic space group P21/n with cell parameters a = 12.2360(7), b = 17.156(1), c = 16.2040(6) Å, V = 3354.1(3) Å3, and Z =4. Of the reflections measured a total of 2514 unique reflections with F2 > 3σ(F2) was used during subsequent structure refinement. Refinement converged to R1 = 0.066 and R2 = 0.071. Structural studies showed that the chromium atom had a slightly distorted pseudo-octahedral configuration about the metal center with two phosphine groups of o-carborane occupying the equatorial plane cis-orientation to each other. These metal carbonyl complexes are rapidly converted to the corresponding metal carbene complexes, [(CO)3M=C(OCH3)(CH3)]-1,2-(PPh2)2-1,2-C2B10H10 (M= Cr 3a, Mo 3b, W 3c), via alkylation with methyllithium followed by O-methylation with CF3SO3CH3.

• The Korean Journal of Zoology
• /
• v.7 no.1
• /
• pp.6-8
• /
• 1964

1. A total of 260 individuals of carp was collected from Nakdong and Hyungsan Rivers. 2. The normal dental form of carp is 3, 1, 1-1, 1, 3, but the author observed abnormal dental forms (3, 2 or 1, 1, (+1)-1, 1 or 2, 3). 3. Variation ratios of dental forms are : A. Normal form; 3, 1, 1-1, 1, 3..........88.85% B. Abnormal forms; a. 3, 2, 1-1, 1 or 2, 3..........2.31% b. 3, 1, 1, 1-1, 1 or 2, 3..........5.00% c. 3, 2, 1, 1-1, 1 or 2, 3..........3.07% d. with 2 or 3 bone processes..........0.77% 4. The ratios among the length of first row (I), length of second tooth in first row ($I_{-2}$) and mid line(M) are as follows; 5. The growth of bone process beside second row tooth is not concerned with the body growth. 6. The number of the groove on second tooth in first row increases according to the growth of body.

• Journal of the Korean Chemical Society
• /
• v.54 no.4
• /
• pp.429-436
• /
• 2010

A series of some biologically active halogenopurines were synthesized from commercially available guanine (1). The reaction of guanine with acetic anhydride yielded 2,9-diacetylguanine (2-1) by acetylation reaction. Further treatment of 2-1 with $POCl_3$ by PEG-2000 phase transfer catalysis furnished the important compound 3a, then 2-amino-6-halogenopurines (3b-d) were obtained through chlorine-exchange halogenations between KX and 3a by TPPB phase transfer catalyst. Further, 2-halogenopurines (2-2a-d, 4-2a-d, 5a-d) were efficiently prepared from 2-amino-6-substituted purines (1, 3a, 4-1) via a diazotization catalyzed by their corresponding CuX, and some new compounds 2-2a, 2-2c, 2-2d, 4-2c, 4-2d, 5b, 5c and 5d have been discovered. The structures of synthesized compounds were mainly established on the basis of their elemental analysis, $^1H$ NMR, as well as their mass spectral data. All the title compounds were screened for their antifungal activities, and some of the compounds showed promising activity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.2
• /
• pp.108-112
• /
• 2003

The calculated and measured dielectric constants of (1-x)(A $l_{1}$2/ T $a_{1}$2/) $O_2$-x(M $g_{1}$3/ T $a_{2}$3/) $O_2$ (0$\leq$x$\leq$1.0) solid solutions were investigated by variations of ionic polarizability and crystal structure. (A $l_{1}$2/ T $a_{1}$2/) $O_2$ and (M $g_{1}$3/ T $a_{2}$3/) $O_2$ were orthorhombic and tetragonal trirutile structure, respectively. When (A $l_{1}$2/ T $a_{1}$2/) $O_2$ was substituted by (M $g_{1}$3/ T $a_{2}$3/) $O_2$, the phase transformed to tetragonal structure over 60 mole. Because the total ionic radius of [(Mg+2Ta)/3]$^{4+}$ was slightly bigger than one of [(Al+Ta)/2]$^{4+}$, the lattice parameters increased with an increase of (M $g_{1}$3/ T $a_{2}$3/) $O_2$ substitution. The measured dielectric constant increased with an increase of (M $g_{1}$3/ T $a_{2}$3/) $O_2$ substitution and coincided with dielectric mixing rule and the calculated dielectric constant with the molecular additivity rule. There were some differences between the measured and the calculated dielectric constant. The reason of the lowered dielectric constant comparing with the calculated one was compressed stress due to the electronic structure of tantalum.

• Korean Journal of Crystallography
• /
• v.1 no.1
• /
• pp.14-18
• /
• 1990

Econazole nitrate, 1-{2-[(4-chlorophenyl)methoxy]-2-(2,4-dichlorophenyl) ethy1}-1H-imidazole mono-nitrate.C18 H16 CI13 N3 O4 Mw=444.7 Monoclinic P/2₁c,a=17.337(4)A, b=15.191(5), c=7.601(3)A, β=91.72(2)', V=2000.9A3, Z=4, Dc=1.49g/cm3, Dm=1.45g/cm3(mo-ka)= 0.7107A, μ=4.31cm-1, F(000)=912.0, T=298'K, final R=0.061 for 1330 unique observed reflection. Each of the three ring system for the stars with B,A and C ring in order whilst A and C ring of econazole lie close to the same plane which is nearly 60˚with B ring. The hydrogen binding nitrogen of C ring and oxygen of nitrate contributes to stailization of econazole nitrate. Intr and intermolecular distances and angles are within the values recorded for simiar compounds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.11a
• /
• pp.80-84
• /
• 1997

In this experiment, A1$_2$O$_3$ thick films were prepared by electrophoretic method using A1$_2$O$_3$ fine Powder of which composition were FA-5-500 and FA-5-900. The growth behavior of A1$_2$O$_3$ thick films were characterized as preparation conditions, such as applied voltage, deposition time and adding conditions. As a result, A1$_2$O$_3$ thick films were successfully fabricated by electrophoretic method on molybdnum plate in which etanol and distilled used were used as a solvent. Deposition conditions for good uniformity of the A1$_2$O$_3$ thick films were applied voltage of 60volts, deposition time of 2 seconds, heat treatment at 1$700^{\circ}C$ for 5 minutes.

• Journal of the Korean Ceramic Society
• /
• v.40 no.1
• /
• pp.18-23
• /
• 2003

Composite powder of$B_4C-A1_2O_3$was prepared from a mixed powder of$B_2O_3/A1/C$by SHS under argon pressure instead of using a chemical furnace. A mixture of$B_2O_3,$Al and C powder (equivalent amounts to the reaction,$2B_2O_3+4A1+C=B_4C+2A1_2O_3)$was ball milled for 2 h. The mixed powder was placed in a SHS reactor and filled with 10 atm of argon gas and ignited. The inner and outer products were the same by XRD analysis. It was consisted of a composite powder of$B_4C-A1_2O_3$without $AlB_{12}/C_2$which was always produced using a chemical furnace. The composite powder was about$60~100{mu}m$size which was composed of crystalline particles of about 0.3~l${mu}m$size. But when 15 atm of argon was employed, partial sintering took place to give rise hard composite powder of$15~25{mu}m$$B_4C$with $0.1~0.2{mu}m$$A1_2O_3.$

• Korean Journal of Crystallography
• /
• v.1 no.2
• /
• pp.84-90
• /
• 1990

1,3-Diazatricyclo (5.2.1.Os .to) decane-2,11-dione , C8H10N2O2. MW=166.15, Monoclinic, P2/n a= 6.585(7) , b=9.089(4), c=12.937(10)A, β=95.72(5)˚, V=770.4A3, Z=4, Dc=1.43(4) g/cm3, λ (Mo Ka)=0.7093A, r=1.Ocm-1, T=295˚K, final R=0.037 for 698 unique observed reflections. The compound is the product of the intramolecular (2+2) photocycloaddition of Nl-(w-butenyl)uracil and belongs to a (5.2.1.O5.10) tricyclic system. A pair of molecules related by the inversion symmetry are held together by the strong hydrogen bonding interactions between 02 and H3 of the uracil moiety.

• Archives of Pharmacal Research
• /
• v.13 no.4
• /
• pp.310-313
• /
• 1990

Hantzsch synthesis of 5-formyluracil (1) methyl acetoacetate (2) and methyl 3-aminocrotonate (3) gave 2, 6-dimethyl-4-(2, 4-dioxo-5-pyrimidy)-1, 4-dihydropyridine-3, 5-dicarboxylic acid dimethylester (4a) in 54.6 yield. As the same procedure, 1, 3-dimethyl-5-formyl-uracil (6) gave 2, 6-dimethyl-4-(1, 3-dimethyl-2, 4-dioxo-5-pyrimidyl)-1, 4-dihydropyridine-3, 5-dicarboxylic acid dimethyl easter (7a) IN 52.2% yield. 4a was methylated to afford 7a also in 52% yield.