• Analytical Science and Technology
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• v.20 no.5
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• pp.448-451
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• 2007

A new bis(dicyclohexylammonium) chromate dihydrate complex, $[(C_6H_{11})_2NH_2]_2[CrO_4]{\cdot}2H_2O$, (I), has been synthesized and its structure analyzed by FT-IR, EDS, elemental analysis, ICP-AES, and single crystal X-ray diffraction methods. The Cr(VI) complex (I) is tetragonal system, I${\bar{4}}$2d space group with a = 12.5196(1), b = 12.5196(1), c = $17.3796(3){\AA}$, a = ${\beta}$ = ${\gamma}$ = $90^{\circ}$, V = $2724.09(6){\AA}^3$, Z = 4. The crystal structure of complex (I) consists of tetrahedral chromate $[CrO_4]^{2-}$ anion, two organic dicyclohexylammonium $[(C_6H_{11})_2NH_2]^+$ cations and two lattice water molecules. The chromate anion and protonated dicyclohexylammonium cation is mainly constructed through the ionic bond. The cyclohexylammonium rings of the dicyclohexylammonium cation take the chair form and vertical configuration with each other. The N-H${\cdot}$O and O-H${\cdot}$O hydrogen bond networks between the $N_{dicyclohexylammonium}$, $O_{water}$ and $O_{chromate}$ atom lead to self-assembled molecular conformation and stabilize the crystal structure.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.708-712
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• 2012

Ionic liquids (ILs) existing as liquid state at room temperature are composed of a immense heterocyclic cation and inorganic anion which is smaller than cation's size. Thus, the species of cation and anion as well as the length of alkyl group on the cation have influence on their physical properties. Their outstanding properties such as non-volatility, thermal stability and wide range of electrochemical stability make these materials excellent candidates for green solvent which can substitute the conventional organic solvents. In this study, ILs based on imidazolium cation have been synthesized such as 1-butyl-3-methylimidazolium bromide ([BMIM][Br]), 1-butyl-3-methylimidazolium chloride ([BMIM] [Cl]), 1-butyl-3-methylimidazolium iodide ([BMIM][I]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][$BF_4$]). The density, viscosity, refractive index, heat capacity and ionic conductivity of [BMIM][Br], [BMIM][I], and [BMIM] [$BF_4$] were measured over range of temperature of 293.2 to 323.2 K. The density and refractive index values of [BMIM][I] were the highest among three ILs and the viscosity values of [BMIM][Br] were the highest among three ILs. The heat capacities [BMIM][$BF_4$] were higher than those of [BMIM][Br]. The ionic conductivities of [BMIM][$BF_4$] were higher than those of [BMIM][I].

• Journal of the Korean Chemical Society
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• v.16 no.6
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• pp.354-360
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• 1972

Formation of the complexes of barium, strontium and calcium ions with dibasic organic acid ions in dilute solution was studied at room temperature, utilizing the equilibrium exchange technique which involved the uses of radioactive alkaline earth metal ions and cation excbange resin. The organic acids used in this study were succinic and tartaric acids, and the solvents used were water, 20 % acetone-water and 20 % ethanol-water. The pH of the solutions was controlled to 7.2∼7.4, and the ionic strength of the solutions was kept at approximately 0.1. The experimental results indicated that the alkaline earths formed one-to-one complexes in solution with the dibasic acids examined, and that the relative stabilities of the complexes increased in the order: $Ba^{++}; succinic

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.223-237
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• 1996

플라스틱재료의 강도, 인성, 경직성, 탄성 등과 같은 기계적 특성을 개선시켜 주기 위해 kaoline, talc, sand, quartz 등과 같은 규산염을 첨가하여 복합재료를 만들고자 하는 연구가 상당히 활발하다. 이와 같이 다양한 규산염이 복합재료의 강화재 또는 첨가제로 사용되는 반면에, 규산염가운데 공업적으로 이용도가 가장 높은 montmorillonite는 아직도 복합재료의 강화재로 폭 넓게 이용되고 있지 못한 실정이다. 이론적으로 볼 때, 높은 분자량을 지니는 무기고분자 (예; inorganic montmorillonite)와 유기고분자 (organic polymer)를 gkadbk는 실질적인 무기-유기 결합물질의 생성이 가능할 수 있으며, 이에 대한 연구 또한 시도되고 있다. 이렇게 해서 얻게 되는 무기-유기 복합체, 즉 montmorillonite로 강화된 플라스틱 복합재료 bumper를 사용함으로써 접촉 또는 충돌시 충격완화의 효과를 가져 올 수 있어 안정성이 좋아지고, 내파괴성이 높기 때문에 비강화 플라스틱재료보다 더 오래 사용할 수 있으므로 경제성이 좋을 뿐만 아니라, 폐품의 감소로 인해 환경보호에도 일익을 담당할 수 있다. 따라서, 본 연구에서는 이러한 montmorillonite강화 플라스틱 복합체를 얻기 위해 우선 무기-유기 고분자물질의 형성이 가능한가를 조사분석하였다. 이를 위해 먼저 amontmorillonite의 층사이에서 화학반응이 수행될 수 있는 충분한 공간을 얻고자 Na-Montmorillonite 층사이의 Na+-이온을 긴 알킬사슬을 취하는 유기 양이온으로 치환시켜 주었다; 이렇게 해서 얻은 유기양이온-몬트모릴로나이트 층간화합물 (Organic cation-Montmorillonite Intercalations-complex)내에 유기 단분자 (organic monomer)를 추가적으로 삽입시킨 후, montmorilonite의 층내에서 증합반응시켜 고분자화해 줌으로써 무기고분자와 유기고분자가 서로 결합된 무기-유기고분자 결합물질을 형성하고자 하였다. X-선 및 IR-분석결과 층내에서의 유기단분자의 고분자화 반응이 성공적으로 이루어 졌음이 입증되었다.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.743-747
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• 2001

New azomethine metal complexes were synthesized systematically and characterized. Beryllium, magnesium, or zinc ions were used as a central metal cation and aromatic azomethines (L1-L4) were employed as a chelating anionic ligand. Emission peaks o f the complexes in both solution and solid states were observed mostly at the region of 400-500 nm in the luminescence spectra, where blue light was emitted. Three of them (BeL1 (Ⅰ), ZnL2 (Ⅱ), and ZnL3 (Ⅲ)) were sublimable and thus were applied to the organic light-emitting devices (OLED) as an emitting layer, respectively. The device including the emitting layer of Ⅰ exhibited white emission with the broad luminescence spectral range. The device with the emitting layer of Ⅱ showed blue luminescence with the maximum emission peak at 460 nm. Their ionization potentials, electron affinities, and electrochemical band gaps were investigated with cyclic voltammetry. The electrochemical gaps of 2.98 for I, 2.70 for Ⅱ, and 2.63 eV for Ⅲ were found to be consistent with their respective optical band gaps of 3.01, 2.95 and 2.61 eV within an experimental error. The structure of OLED manufactured in this study reveals that these complexes can work as electron transporting materials as well.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.683-688
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• 2015

Nowadays, sustainable and environment-friendly agriculture has become an important issue all around the world, and repeated applications of mineral and/or organic fertilizer will probably affect mineral nutrient dynamics in soil in the long term but only a limited number of observations are available. This study was carried out to investigate whether there is any influence of different fertilizer management for red pepper (Capsicum annuum L.) cultivation on soil physicochemical properties, leaf mineral content, yield and fruit quality in the aspect of long-term practice in open field condition. NPK, NPK+compost, compost only, and unfertilized control plot were included in the treatments. The application of chemical fertilizer and/or compost repeated annually for 17 years from 1994 to 2011. Soil organic matter content was higher in compost treatments than in no-manure treatments. Available phosphate and the yield of red pepper were highest in NPK+compost treatment followed by NPK (chemical fertilizer), compost, and control. The results indicate that in the long term, nitrogen supply is still needed for increasing red pepper yield, but reduction in the use of chemical fertilizer could be also possible with the proper application of compost.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.19-23
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• 1975

In order to find out the effect of long-term annual additions of organic matter on the physico-chemical properties of paddy soil, the soil with and without compost application has been analysed. 1. There was no significant difference in the particle size distribution between compost and uncompost treatment, however, hydraulic conductivity, sedimention volume were remarkedly increased in compost. 2. Bulk density and soil strength were decreased in organic matter additions, but porosity increased. 3. Relative to Atterberg Limits, liquid limit, plastic limit, and elastic index were increased in compost. 4. Aggregate size distribution was slightly increased in additions of organic matter. 5. Regarding to chemical properties, pH, organic matter content, C.E.C. and extractable cation were increased in organic matter additions.

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.413-422
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• 2005

This study was carried out to investigate the effect of different mixture ratios of vermicasts on the growth of leaf beet(Beta vulgaris var. cicla), young radish (Raphanus sativus L), spinach(Spinacia oleracea) and lettuce(Lactuca sativa) The mixture of ratios of vermicast(fermented pig manure with sawdust) and peatmoss were 100%+0%, 60%+40%, 40%+60% and 0%+100%(control), respectively. The bulk density, particle density, pH, electrolytic conductivity, ash, total nitrogen, cation exchange capacity, available phosphorous and exchangeable cations increased significantly compared to those grown in the 100% of peatmoss(control). The significantly higher values of plant length, leaf area, shoot dry weight, root weight, root length and biological yield obtained were $40{\sim}100%$ and 40% of vermicast in leaf beet and lettuce, respectively. The young radish and spinach showed that significantly differences of shoot dry weight, root weight and biological yield in the mixture ratios of vermicast were $40{\sim}60%$ and 40% in young radish and spinach, respectively.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.813-827
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• 2015

This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~394.1 mg/kg. In case of exchange cation, the concentration for compost+green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.

• Analytical Science and Technology
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• v.8 no.1
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• pp.33-40
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• 1995

Only trace amounts of hydroxide ion can be extracted from aqueous phase into organic phase by Tetra-n-Butyl Ammonium Chloride(TBAC). Addition of small amounts of primary alcohols, particularly certain dials, dramatically changes the behavior of Phase Transfer Catalysis systems, and surprising amounts of base can be found in the organic phase. Quantitative measurements were carried out for the extraction amounts of primary alkoxides, secondary alkoxides, and diol anions into organic phase. On the other hand, the selectivity constants for extraction of primary alcohols and benzylalcohol could be separated to the equilibrium constants of the ion pairs such as $Q^+RO^-$ and $Q^+Cl^-$ in the aqueous and organic phases and this distribution coefficients between phases on anions respectively. In a word, the colligated property for the selectivity of $Q^+RO^-$ in which $Q^+$ is quaternary cation and $RO^-$ alkoxide ion could be discussed in more detail by using of the corresponding free energies to the various constants mentioned.