• 제목/요약/키워드: Iodine Chemistry

검색결과 216건 처리시간 0.027초

Ailanthoidol Derivatives and their Anti-inflammatory Effects

  • Lee, Na-Li;Lee, Jae-Jun;Kim, Jin-Kyung;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권6호
    • /
    • pp.1907-1912
    • /
    • 2012
  • Ailanthoidol showed a strong $anti$-inflammatory effect in a previous result. Ailanthoidol derivatives were prepared for the $anti$-inflammatory test using Sonogashira coupling, iodine induced cyclization and Wittig reaction. $Anti$-inflammatory effects of the prepared ailanthoidol derivatives were examined in lipopolysaccharide (LPS)-stimulated RAW 264-7 macrophages. The results showed that some ailanthoidol derivatives inhibited significantly the production of inflammatory mediator nitric oxide.

화학반응을 이용한 일반 프린트용지의 잠재지문 현출에 관한 연구 (The studies of developing latent fingerprint in general print papers by chemical reaction)

  • 노승찬;최미정;김만기;이오택;박성우
    • 분석과학
    • /
    • 제20권2호
    • /
    • pp.155-163
    • /
    • 2007
  • 다공성 지류의 증거물은 문서위조, 유괴, 사기와 테러 등의 범죄현장에서 발견된다. 본 실험은 다공성 지류인 일반 프린트 용지와 신문지의 잠재지문 현출에 Ninhydrin, 1,8-diazafluoren-9-one (DFO) 그리고 Iodine fuming의 효과를 평가하고 지류에 따른 적절한 방법을 확인하고자 하였다. 일반 프린트 용지의 경우 Ninhydrin과 DFO의 처리보다 Iodine fuming법으로의 처리가 현출효율이 증대되었다. 신문지의 경우 Iodine fuming 법으로의 현출이 효과적이었으며 DFO로의 재처리와 blue light 광원에서 orange red filter의 사용으로 현출의 증가를 보였다. 또한 현출영상의 개선을 위해 Digital Imaging System(DIS)를 이용한 결과 효율의 증가를 확인할 수 있었다.

피리딘과 할로겐 또는 할로겐간 화합물 사이의 전하이동 착물생성에 관한 열역학적 연구 (The Thermodynamics of the Formation of Pyridine-Halogen and Interhalogens Charge Transfer Complexes)

  • 권오천;경진범;최기준
    • 대한화학회지
    • /
    • 제26권6호
    • /
    • pp.363-368
    • /
    • 1982
  • 피리딘과 요오드, 일브롬화요오드 및 일염화요오드 사이에 생성되는 전하이동 착물을 사염화탄소 용액내에서 자외선 분광 광도법을 사용하여 연구한 결과$ C_5H_5N{\cdot}I_2}$, $ C_5H_5N{\cdot}IBr$$ C_5H_5N{\cdot}ICl$형의 1:1 분자 착물이 생성됨을 알았다. 이들 착물 생성에 대한 흡수최대는 온도가 상승함에 따라 blue shift 되므로 이를 고려하여 각 온도에서의 평형 상수와 흡광계수를 구하였다. 이 값으로부터 이들 착물 생성에 대한 ${\Delta}H$, ${\Delta}D$${\Delta}S$의 열역학적 파라미터를 산출하였다. 이 결과 착물의 상대적 안정도가 다음과 같은 순서로 됨을 알 수 있었다. $ C_5H_5N{\cdot}I_2$ < $ C_5H_5N{\cdot}IBr$ < $ C_5H_5N{\cdot}ICl$ 이 순서는 피리딘에 대한 그들의 상대적 산성도를 의미하며 전자수용체의 편극율 및 할로겐 원자의 전기 음성도의 차이에 의하여 설명될 수 있다.

  • PDF

교류 전압전류계의 제작과 요오드 정량에의 응용 (An AC Voltammetric Instrumentation and Its Application in Iodine Analysis)

  • 김문순;정의한;정기호;심윤보
    • 분석과학
    • /
    • 제5권1호
    • /
    • pp.91-96
    • /
    • 1992
  • 실험실에서 간단하고 값싼 교류 전압전류계를 제작하였다. 이 장치는 직류함수 발진기, lock-in 증폭기로 구성되어 있다. 1M 황산용액에서 백금을 작업전극으로 하여 $1{\times}10^{-3}M$ ${Fe(CN)_5}^{3-}$의 가역계에서 CV 전압전류곡선과 교류 전압전류곡선을 구한 데이터로부터 이 장치가 잘 작동되는 것으로 증명되었다. 요오드에 대한 정량분석 결과도 구하였다.

  • PDF

Study of Thyroid-Related Hormones During Second Trimester of Pregnancy

  • Laeeq Faiqa;Nagra Saeed Ahmad;Elahi Shan
    • Nutritional Sciences
    • /
    • 제8권3호
    • /
    • pp.196-199
    • /
    • 2005
  • A study during second trimester of pregnancy was conducted among 100 women from a population with mild to moderate deficient iodine intake (median 7 ${\mu}g$/L)to monitor the changes in serum free thyroxin ($FT_4$), triiodothyionine ($T_3$) and thyrtropin (TSH). Thyroid related hormones were assessed using radioimmunoassay (RIA) and immunoradiometricassay (IRMA). As compared with non pregnant women, mean $FT_4$ levels decreased, $T_3$ levels increased and TSH levels were slightly depressed in pregnant women. Mean $FT_4$ concentration reached its highest level in the $4^{th}$ month and linearly decreased until the $6^{th}$ month. Mean $T_3$ level remained almost constant during $2^{nd}$ trimester of pregnancy. Mean TSH level remained unaltered during the $4^{th}$ and $5^{th}$ months and was slightly lower than that for the control group. However, these differences were statistically insignificant At the end of the second trimester, hypothyroxinemia and $T_3$ levels greater than the upper limit of the laboratory reference range were found in $34\%$ and $38\%$ of women, respectively. These changes in thyroid hormones reflect typical adaptations of the thyroid gland during pregnancy to the limited availability of iodine.

Effects of temperature and solution composition on evaporation of iodine as a part of estimating volatility of iodine under gamma irradiation

  • Yeon, Jei-Won;Jung, Sang-Hyuk
    • Nuclear Engineering and Technology
    • /
    • 제49권8호
    • /
    • pp.1689-1695
    • /
    • 2017
  • As a part of evaluating the volatility of iodide ions subjected to gamma irradiation, $I_2$ evaporation experiments were performed with $I_2$ and $I^-$ mixed solutions in the temperature range $26-80^{\circ}C$ in an open, well-ventilated space. The evaporation of $I_2$ was observed to follow primarily first order kinetics, depending on the $I_2$ concentration. The evaporation rate constant increased rapidly with increase in temperature. The presence of $I^-$ slightly reduced the evaporation rate of $I_2$ by forming relatively stable $I_3^-$. The effect of $Cl^-$ at <1.0 wt% on $I_2$ evaporation was insignificant. The evaporation rate constants of $I_2$ were $1.3{\times}10^{-3}min^{-1}\;cm^{-2}$, $2.4{\times}10^{-2}min^{-1}\;cm^{-2}$, and $8.6{\times}10^{-2}min^{-1}\;cm^{-2}$, at $26^{\circ}C$, $50^{\circ}C$, and $80^{\circ}C$, respectively.

The Study on the Physicochemical Properties of Fluid under High Pressure (1). Effects of Pressure and Temperature on the Pentamethyl Benzene-Iodine Charge Transfer Complex in n-HexaneⅠ

  • Kim, Jeong-Rim;Kwun, Oh-Cheun
    • Bulletin of the Korean Chemical Society
    • /
    • 제6권2호
    • /
    • pp.74-79
    • /
    • 1985
  • The stabilities of the charge transfer complexes of pentamethyl benzene with iodine in n-hexane have been investigated by UV-spectrophotometric measurements at 25, 40 and 60$^{\circ}C$ up to 1600 bars. The equilibrium constant of the complex formation was increased with pressure while being decreased with temperature raising. Changes of volume, enthalpy, free energy and entropy for the formation of the complexes were obtained from the equilibrium constants. The red-shift at higher pressure, the blue-shift at higher temperature, and the relation between pressure and oscillator strength have been discussed by means of thermodynamic functions. In comparison with the results in the previous studies, the absolute values of ${\Delta}$V at each temperature were increased with the number of methyl groups of polymethyl benzene. However, it can be seen that both ${\Delta}$H and ${\Delta}$S show extreme behaviors in durene near atmospheric pressure but they are negatively increased with the number of methyl groups near 1600 bar. This order of the thermodynamic parameters may be a measure of the relative basicities of polymethyl benzenes toward iodine under each pressure, and these phenomena are explained in terms of a positive inductive effect and a steric hindrance effect of the polymethyl benzene molecule.

Trajectory Studies of Methyl Radical Reaction with Iodine Molecule

  • Lee, Sang-Kwon;Ree, Jong-Baik;Kim, Yoo-Hang;Shin, Hyung-Kyu
    • Bulletin of the Korean Chemical Society
    • /
    • 제26권9호
    • /
    • pp.1369-1380
    • /
    • 2005
  • The reaction of methyl radical with iodine molecule on an attractive potential energy surface is studied by classical trajectory procedures. The reaction occurs over a wide range of impact parameters with the majority of reactive events occurring in the backward rebound region on a subpicosecond scale. A small fraction of reactive events take place in the forward hemisphere on a longer time scale. The ensemble average of reaction times is 0.36 ps. The occurrence of reactive events is strongly favored when the incident radical and the target molecule align in the neighborhood of collinear geometry. Since the rotational velocity of I2 is slow, the preferential occurrence of reactive events at the collinear configuration of $CH_3{\ldots}I{\ldots}$I leads to the reaction exhibiting an anisotropic dependence on the orientation of $I_2$. During the collision, there is a rapid flow of energy from the $H_3C{\ldots}$I interaction to the I-I bond. The $CH_3I$ translation and $H_3C$-I vibration share nearly all the energy released in the reaction, and the distribution of the vibrational energy is statistical. The reaction probability is $\cong$0.4 at the $CH_3$ and I2 temperatures maintained at 1000 K and 300 K, respectively. The probability is weakly dependent on the $CH_3\;and\;I_2$ temperatures between 300 K and 1500 K.