MnCO_3 熱分解時 生成된 α-Mn_2O_3 및 r-Mn_2O_3의 示差熱曲線에 對한 考察

丁學鎭,金一斗,丁梧鎭 조선대학교 기초과학연구소 1978 自然科學硏究 Vol.1 No.1

Each transformation temperature of manganeseoxide produced when MnCO_3 is decomposed by heat, and various modifications of Mn_2O_3 have been studied with the differential thermal curves of the D.T.A. If MnCO_3 was heated in air, the intermediate products such as MnO, MnO_2 and Mn_2O_3 were produced at about 100℃, 410℃∼610℃ and 650℃∼850℃ respectively, and Mn_2O_3 was transformed into Mn_3O_4 at 850℃∼890℃, and then Mn_3O_4 maintained the minimum energy state. The transformation temperature of the modifications are as follows : α-Mn_2O_3(890℃∼970℃)￣→Mn_3O_4, ??-Mn_2O_3(610℃∼710℃)￣→α-Mn_2O_3(785℃∼890℃)￣→Mn_3O_4. The more the amount of the given samples, the higher the restoration temperatures of transformation. The maximum temperatures, however, were kept relatively constant. The differential thermal curve of α-Mn_2O_3 showed a small peak, while that of ??-Mn_2O_3 showed a sharp and broad peak.

세자리 Schiff base ligand 금속착물에 관한 연구(Ⅰ)

정학진,정오진,서혁춘 조선대학교 기초과학연구소 1986 自然科學硏究 Vol.9 No.1

The tridenate schiff base legand, 2-(salicyliden imino) -p- cresol, has been synthesized from salicylialdehyde and 2-amino- p- cresol by Duff method. This schiff base ligand has been reacted with Pd(Ⅱ), Rh(Ⅲ) and Nb(Ⅴ) metallic ions to form new complexes: Pd(Ⅱ)C_14H_12NO_2·H_2O, Rh(Ⅲ)C_14H_12NO_2·2H_2O and Nb(Ⅳ)(C_14H_12NO_2)_2·2H_2O Cl. The compositions and structures of the ligand and complexes have been discussed by element analysis, Kahl Fischer's moisture titration method, thermal analysis, ultraviolet spectroscopy, infrared spectroscopy, ^1H-nmr spectroscopy, X-ray diffraction patterns and electric conductance, respectively. It seems the Pd(Ⅲ) and Nb(Ⅴ) complexes have the structure of tetra- , hexa-and oct-acoording system, respectively and the mole ratio of metallic ion to ligand for the Pd(Ⅱ) and Rh(Ⅲ) complex are 1:1, but Nb(Ⅴ) complexis 1:2. Pd(Ⅱ), Rh(Ⅲ) and Nb(Ⅴ) complex with tridenate schiff base ligand have been coordinated with one and two molecules of water in accordance with the kinds of complexes, and the Rh(Ⅲ) complex has the structure of dimer bridge bonded with oxygen atom. The Pd(Ⅱ) and Rh(Ⅲ) complexes are nonpolar molecules but Nb(Ⅴ) complex is a polar molecule which will be dissociated in Nb(Ⅴ)(C_14H_12NO_2)_22H_2O.Cl^- and has structure of 1:1 electrolyte. All of the complexes have phenomena of π- π^* in ligand and d-d and d-π^* charge transfer between ligand and metal.

師範大學 自然敎育系學科의 敎育課程 內容 檢討 및 改善에 關한 硏究

丁學鎭,姜宗煥,金一斗,朴相翊,崔熔燮,金順愛,林仁澤 조선대학교 교과교육연구소 1982 교과교육연구 Vol.5 No.-

Silver Sulfide Halide 막전극의 특성(Ⅱ)

정학진,김일두,박성규,정오진 조선대학교 기초과학연구소 1982 自然科學硏究 Vol.4 No.2

The responsive characteristics of the halide ion selective membrane electrodes were investigated in test solutions by X-Y recording potentiometer (Watanabe type) equipped with saturated caromel electrode, as reference electrode and Ag_3SX/PVC-THF membrane electrode, as lndicating electrode. The results are as follows ; 1) The potential responses to selective membrane electrode of Ag_3SX, have the best sensitivity, reproductcity and stability in the case of Ag_SX membrane electrode coated with 0.1% P. V. C. 2) Ag_3SX-0.1% P. V. C. pellet, selective membrane electrode showed a good linear potential rasponse to the activities of halide in the concentration range from 10^-2 to 10^-6 M. 3) The electrode was not shown potential response significantly to the other cation, but exhibited a linear responses to silver ion activities in the concentration range from 10^-1 to 10^-6 M. 4) These membrane electrodes was found to be the most stable potential response and corresponded to nearly Nernstian slope when potential responses were determined by potentiometer after immersing selective membrane electrode in the suppersaturated solution of each selective halide ion. 5) The potential responses of these membrane electrodes showed a linear form in the pH range from 3.0 to 10.0. 6) The other of selective potential responses to Ag_3SX membrane electrodes was in the order of β-Ag_3SI>Ag_3SBr>Ag_3SCl and the orther of selectivity to Ag_3SI membrane electrode was in the order of I^->Br^->Cl^- in the test solutions. 7) The Ag_3SX membrane electrodes were more stable than AgX membrane electrodes.

N_2O_2 및 N_3O_2형 거대고리 리간드와 Mo(Ⅵ) 착물생성에 관한 연구

정학진,정오진,조정환,김장영 조선대학교 기초과학연구소 1985 自然科學硏究 Vol.8 No.1

The macrocyclic ligands with N_3O_2 and N_2O_2 ring were synthesized from 2-hydroxybenzaldehyde, 1, 2-dibromoethane, 2-2´-diethylenetriamine and tthylenediamine. It was investigated that the determination of characteristics of structures, complex structure changed by thermal decomposition, and determination of mole ratios of complexes synthesized from these ligands and Mo(Ⅳ) ion in DMF solution by the contineous variation method of ultraviolet spectrophotometry. ir-spectrophotometry, thermal and element analysis. The complexes of MoOC_20H_27N_3O_2 is not soluble in water, but sparingly soluble in ethanol, methanol and acetone, And this complex in nonpolar macromolecule, which has the formulas of MoOC_20H_27N_3O_2 and MoO_3. The transition temperatures of phase change were 226℃, 615℃, and 800℃ in air, respectively. Those complexes have structures of hexa-coordinated system, and mole ratios of molybdenium(Ⅳ) metallic ion to ligands are 1 : 1. The complex of Mo(Ⅳ) with macrocyclic ligand of N_3O_2 ring shows increasing phenomenon of spectrophotometric intensity in proportion to N_3O_2 owing to the abolity cooordinated with H_2O coming out of Mo(Ⅳ) ion. The complexes of Mo(Ⅳ) with macrocyclic of N_3O_2 and N_2O_2 have the structures with equal composition ratio in the state of solid and solution.

Crown Ethers Thorium(Ⅳ) Nitrate Hydrate 착물에 관한 연구

정학진,서혁춘 조선대학교 기초과학연구소 1986 自然科學硏究 Vol.9 No.1

The hydrated thorium(Ⅳ) nitrate have been reacted with the crown ethers of the different cavity size in methanol and aceton solvent, respectively. The properties and structures of these complexes are discussed by the element analysis, Kahl-Fisher moisture titration, thermal analysis, X-ay diffraction, ultraviolet and infrared spectroscopy, and electric conductivity. All of the complexes and the nonaccordinated systems with the three, four and five molecules of the hydrates, and the mole ratio of metallic ion to crown ether ligands are 1:1. The structures of the all complexes are different in accordance with the kinds of solvents, but coordinating number and mole ratio are constant in all complexes. The molar absorptivity of the complex obtained in aceton solvent is increased by coordinated bonding of the thorium(Ⅳ) ion to the ligands because the coordinating power of molecule of aceton is larger than that of water. The hydrated thorium(Ⅳ) nitrate complexes with crown ethers have the structure of 1:4 electrolytes deduced from 466-479 ohm^-lcm M^-1. These complexes have been formed by the electrostatic attraction and it is found the hydrated thorium(Ⅳ) nitrate complex with 15-crown-5 ligand is the most stable because thorium(Ⅳ) ion is bonded inside of the ligands. Whereas the other complexes are bonded outside of the cavity of the crown ether because the size of thorium(Ⅳ) ion is smaller or larger than that of the other crown ethers.

大學敎育改革에 관한 몇가지 提言

丁學鎭 조선대학교 교과교육연구소 1982 교과교육연구 Vol.5 No.-

溶媒添加에 따른 Ethylene Disulfide Dibenzoic Acid와 희토류 금속 ion과의 錯物에 對한 分光學的 硏究(Ⅰ).

丁學鎭,송성식,曺正煥 조선대학교 기초과학연구소 1984 自然科學硏究 Vol.7 No.1

Thiosalicylic acid를 출발물질로 하여 EDDA(Ethylene disulfide dibenzoic zcid) ligand를 합성하였다. 이 ligand는 IR Spectrum과 원소 분석에 의하여 확인하였고 몇가지 희토류 금속이온과 ligand사이에 생성된 착이온의 pH 및 시간에 대한 안정성과 용매첨가에 따른 Complex ion들의 분광학적 현상을 UV분광법으로 확인하였다. 전위차분석법에 의하여 합성된 ligand의 pKa값을 정하고 complex ion들의 금속-리간드간에 존재하는 공유결합성을 ligand의 pKa값과 착이온들의 oscillator strenght 사이에서 얻어진 관계식으로부터 검토하였으며 다음과 같은 결과를 얻었다. 1. 합성된 EDDA ligand의 원소분석결과 이론치에 일치하였으며 IR Spectrum data로부터 aromatic-S-aliphatic 특성 peak와 aromatic-COOH dimer peak를 얻었다. 2. 합성된 EDDA ligand는 4자리 schiff base ligand로 행동한다. 3. 생성된 착이온의 입체적 구조변화는 hypsochromic effect를 갖는 n-π charge transfer complex이다. 4. Lanthanides(Ⅲ)와 EDDA ligand사이에 생성된 complex ion들은 1:1 complex였다. 5. 착이온들의 최대흡광파장은 결합하고 있는 중심금속의 종류에 따라 달라진다. 6. 착이온들에게 몇가지 유기용매를 첨가한 결과 complex ion들의 최대 흡광파장은 bathochromic effect를 갖는다. 7. 착이온들의 P^H 안정성은 pH 6.0∼9.0이며 lanthanides(Ⅲ)와 합성된 ligand를 몇가지 유기용매와 반응시킨때의 시간의 안정성은 30분후이다. 8. Complex ion의 안정도 상수들은 pKa값과 첨가된 용매의 종류의 변화에 따라 달랐다. 9. 착화합물들의 osillator strenght(P_ML) values와 transitonal absorption band들은 P_obs/f_m×10^5 vs。f_M/f_M의 linear dinear diagram과 거의 일치하고 이는 금속-ligand 결합이 -COOH의 산소원자와 황원자들에 의하여 형성되었음을 보여주는 것이다. Ethylene disulfide dibenzoic acid (EDDA) ligand is synthesized with starting matterial of thiosalicylic acid, this ligand is identified with IR spectrum and analytical data of carbon and hydrogen. The stability of time and pH on the complex ions formed between some rare earth metallic ions and ligand synthesized, and spectrophotometrc phenomena of complex ions formed according to the addition of solvent have been investigated by UV.-Vis. spectrophotometry. The pKa values of ligand synthesized have been obtained by the method of potentiotitrator, the covalent bonding property that is existed between metals and ligand of the complex ions has been discussed from the equations given between pKa values of ligand and oscillator strength of complex ions. The results are as follows: 1) The analytical data of hydrogen and carbon of EDDA ligand synthesized correspond with experimental values, the characteristic peaks of aromatic-aliphatic groups and peaks of aromatic-COOH dimer are shown in I R. spectrophotometric data. 2) EDDA behaves as ligand of four site-schiff base. 3) Stereostructure of complex ions formed are n-π charge transfer complexes with hypsochromic effect. 4) Complex ions formed between lanthanides(Ⅲ) and EDDA ligand are 1 : 1 complexes. 5) The λ max. of complex ions are varied depending on the centered metals bonded. 6) The λ max. of complex ions added with various kinds of solvents have bathochromic effect. 7) The pH range of stability is 6.0∼9.0, and stability of time reacted with lanthanides(Ⅲ) and ligand synthesized under various kinds of solvents is 30 minutes. 8) The stability consants of complex ions are varied with the changes of pKa and kinds of solvents added. 9) The oscillator strength(P_ML) of transitional absorption bands of complexes almost corresponds with linnear diagram of P_0bs/f_M×10^6 vs. f_ML/f_M. and these results show that metal-ligand bonding are formed by oxygen atom in rhe carboxyl groups and sulfur atoms.

湖南地方 干拓地 및 內陸土壤의 粘土鑛物에 關한 硏究(Ⅱ)

丁學鎭,金一斗,丁梧鎭 조선대학교 기초과학연구소 1979 自然科學硏究 Vol.2 No.1

A study on the kinds of clay minerals and their geneosis in Hampyoung, Muan series, and cultivating reclaimed land and noncultivating reclaimed land Youngkwang series in the western and southern parts of Korea was carried out by chemical analysis, X-ray diffraction, differential thermal analysis and mineral micrography. The following results were obtained ; 1. In Hampyoung silt clay loam due to Low Humic Cleil soils, the minerals were kaoline, illit and vermiculite. The secondary micerals were quartz, chlorite and gibbstite. A small amount of montmorillorinite was identified in the deep soil. 2. In Muan silt clay loam due to Red Yellow soils, the main mineral was kaoline. The secondary minerals were vermiculite, illite, chlorite and quartz. Especially, a small amount cf gibbsite was identified in the top soil and a small amount of hematite was identified in the deep soil. 3. In cultivating reclaimed land (C groups) and noncultivating reclaimed land (D groups) Youngkwang series, the main minerals were kaolin, illite and vermiculite. The secondary minerals were quartz, chlorite and gibbsite. 3. A composition ratio of clay menerals at cultivating reclaimed land and noncultivating land was nearly constant but the least small amount of kaoline was detected at the top soil of C groups. 4. The clay minerals of latice distance, 7.2-7.4 Å and 3.35-4.27 Å, on the X-ray diffractometer with all soils. Especially, an amount of kaoline among them was abundant but kaoline was apperared much from the deep soil than from the top soil. 5. We could deduce kaoline by endothermic peak (540-570℃) and exothermic peak (920-970℃). This kaoline was deduced with halloysite. 6. The ratio ; SiO_2/Al_2O_3 and exchange capacity of cations in soils were deteted much more from noncultivating reclaimed land than from other soils.

Rare Earth Oxalate Hydrate의 構造變化에 關한 硏究(Ⅱ)

丁學鎭,丁梧鎭,宋基東 조선대학교 기초과학연구소 1984 自然科學硏究 Vol.7 No.1

희토류 옥살산 수화물 및 각 전이점 이후까지 가열하여 얻은 옥살산 시료들의 구조를 원소분석치, 시차열분석법, 열중량분석법, X선회절법 및 전자현미경법으로 연구하였다. 각 희토류는 옥살산 수화물 시료들은 공기중에서 293∼427℃ 사이에서 완전탈수 되어 단사정계 결정에서 무정형의 무수염으로 변한다. 이들 무수물은 346∼698℃ 사이에서 R_2O_2CO_3로 상변화가 생기며 720∼885℃에서 희토류 산화물로 분해된다. 각 희토류 옥살산 수화물의 전이온도와 희토류원소의 원자번호와는 아무런 관계가 없었다. The rare earth oxalate hydrates were synthesized by precipitation method at room temperature. These have the general formula, R_2(C_2O_4)_3. XH_2O. The structures of the hydrates and compounds ignited at each transition temperature have been investigated by analytical data of carbon and hydrogen, differential thermal analysis(DTA), thermogravimetric analysis (TGA) and X-ray diffraction method. The TGA results were similar to all the lanthanides and the DTA results were almost entirely different according to the heating conditions. The lanthanide hydrates lost water in air at the range of 200∼347℃ and monoclinic crystal became the stable anhydrous salt. These anhydrous salts were decomposed into R_2O_2CO_3 at the range of 380∼600℃. The rare earth oxycarbonates have begun to decompose into the rare earth oxide at 600∼885℃. We found that atomic numbers of rare earth elements were not related with each transitional temperatures.