• Title/Summary/Keyword: UV-VIS

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Kinetics of the Formation of Metalloporphyrins and the Catalytic Effect of Lead Ions and Hydrogen Ions

  • Qi, Yong;Pan, Ji Gang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3313-3318
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    • 2014
  • The reaction mechanism of Lead ions catalyzing complexation reactions between TIPP and metal ions was investigated by researching the kinetics of the formation of metalloporphyrins by UV/Vis-spectra, and verified by exploring the formation of metalloporphyrins catalyzed by acetic acid. Kinetics studies suggested that the fluctuations of reaction rate indicated the formation of metalloporphyrin was step-wise, including the pre-equilibrium step (the coordination of the pyrrolenine nitrogens to $Mn^+$) and the rate-controlling step (the deprotonation of the pyrrole proton). In the pre-equalization step, a sitting-atop (SAT) structure formed first with the complexation between larger radius of $Pb^{2+}$ and TIPP, changed the activation, then $Pb^{2+}$ left with the smaller radius of metal ions attacking from the back of the porphyrin ring center. In the rate-controlling step, two pyrrole protons dissociated to restore a stable structure. This was verified by adding acetic acid at different reaction times.

Microwave-assisted Solvent-free Synthesis of Some Dimethine Cyanine Dyes, Spectral Properties and TD-DFT/PCM Calculations

  • Zhang, Xiang-Han;Wang, Lan-Ying;Zhai, Gao-Hong;Wen, Zhen-Yi;Zhang, Zu-Xun
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2382-2388
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    • 2007
  • A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.

Studies on the Dyeing with plant pigments -extraction and UV/VIS spectrum of Carthamus flower- (직물색소에 의한 염색 연구I -홍화의 색소 추출 및 자외가시분광특성-)

  • 신인수
    • Journal of the Korean Home Economics Association
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    • v.32 no.1
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    • pp.229-238
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    • 1994
  • The purpose of this study was to investigate the objectification of coloring matter abstraction of the way to natural dye by cathamus flower. Watersoluble carthamin in the dyeing cathamus flower was removed for the fastness of dyeing and only insoluble carthamon was abstracted which came by solvent such as Sodium hydroxide(NaOH) Potassium hydroxide(KOH) Sodium carbonate(Na2CO3)and Potassi-um carbonate(K2CO3) Carthamon made abstract essence from a carthamus flower out of the pH6, pH7, pH9, pH11, solvent and by using a UV/VIS Spectra according to the change of pH. Silk dyes with solution abstract carthamon and it was treated by 5 kinds of mordant. The table of surface-colors was measured by the number of dyeing the color of silk dyed and by the kind of mordant which treated with and the dyeing was evaluated by measuring Color Fastness to Light and Washing.

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Effect of Batch Melting Temperature and Raw Material on Iron Redox State in Sodium Silicate Glasses

  • Mirhadi, Bahman;Mehdikhani, Behzad
    • Journal of the Korean Ceramic Society
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    • v.48 no.2
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    • pp.117-120
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    • 2011
  • In this study, the redox state of iron in sodium silicate glasses was varied by changing the melting conditions, such as the melting temperature and particle size of iron oxide. The oxidation states of the iron ion were determined by wet chemical analysis and UV-Vis spectroscopy methods. Iron commonly exists as an equilibrium mixture of ferrous ions, $Fe^{2+}$, and ferric ions $Fe^{3+}$. In this study, sodium silicate glasses containing nanoparticles of iron oxide (0.5% mol) were prepared at various temperatures. Increase of temperature led to the transformation of ferric ions to ferrous ions, and the intensity of the ferrous peak in 1050 nm increased. Nanoparticle iron oxide caused fewer ferrous ions to be formed and the $\frac{Fe^{2+}}{Fe^{3+}}$ equilibrium ratio compared to that with micro-oxide iron powder was lower.

Analysis of flavonoids in the mature fruit of Vaccinium uliginosum L. of China

  • Hua, Lian Li;Yoshitama, Kunijiro
    • Advances in Traditional Medicine
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    • v.6 no.1
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    • pp.65-67
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    • 2006
  • In this study, a new extraction method was developed and two kinds of flavonoids were extracted from the mature fruit of Vaccinium uliginosum L. of China. These two kinds of flavonoids were analyzed by spectral and identified by high-performance liquid chromatography (HPLC) and UV/Vis. The extract of the fruit was total acid hydrolyzed. TLC chromatography was subsequently employed to identify the hydrolysate. Two kinds of aglycone flavonoids, quercetin and myricetin, were identified. At the same time PC chromatography was used to identify the monomer sugar in the flavonoids and it was verified as glucose. HPLC, UV/Vis, and Mass spectrum analyses revealed that the flavonoids were quercetin 3-monoglucosides and myricetin 3-monoglucosides.

The preparation of Ultra-thin films of Hexyltriphenyl-phosphonium-TCNQ complex by using Langmuir-Blogett method (Langmuir-Blodgett법을 이용한 Hexyltriphenyl-phosphonium-TCNQ착체의 초박막 제조)

  • Kang, Woo-Hyeang;Kim, Young-Kwan;Sohn, Byoung-Chung;Hwang, Kyo-Hyun;Han, Jong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.2
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    • pp.131-136
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    • 1995
  • Ultra-thin films of hexyltriphenylphosphonium-TCNQ(1:1) complex were formed on various substrates by Langmuir-Blodgett technique, where hexyltriphenylphosphonium-TCNQ(1:1) complex was synthesized by attaching hexyltriphenylphosphonium group to TCNQ. The reaction product was identified with FT-IR, and UV-Vis absorption spectroscopies. The formation of ultra-thin films of hexyltriphenylphosphonium-TCNQ(1:1) complex was confirmed also by FT-IR, and UV/Vis absorption spectroscopies.

Studies on synthesis of Charge Transfer Complex and Preparation Characteristics of its LB Films (전하이동착체의 합성과 Langmuir-Blodgett막의 제조에 관한 연구)

  • Sohn, Mi-Wha;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.2
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    • pp.137-143
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    • 1995
  • Octadecyltrimethylammonium-TCNQ(1:1) complex was synthesized by the reaction of LiTCNQ with octadecyltrimethylammonium bromide and the reaction product was identified with FT-IR and UV/Vis spectroscopies. In order to prepare the LB films, ${\pi}-A$ isotherm characteristics of octadecyltrimethylammonium-TCNQ(1:1) complex were investigated. The LB films of octadecyltrimethylammonium-TCNQ(1:1) complex were formed on various substrates and the formation of ultrathin films of octadecyltrimethylammonium-TCNQ(1:1) complex was confirmed by using FT-IR and UV-Vis spectroscopies.

Layer-by-layer self-assembly colorant multi-layer preparation using natural colorant Berberine and anionic polyelectrolyte (베르베린 천연색소화합물과 음이온고분자전해질을 이용한 layer-by-layer self-assembly 색소다층박막 제조)

  • Son Young-A;Park Young-Min;Lee Seung-Goo;Ravikumar K.
    • Textile Coloration and Finishing
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    • v.18 no.1
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    • pp.28-32
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    • 2006
  • A multi-layer of the dye, natural colorant Berberine, was successfully developed by the self-assembly deposition from water-soluble cationic dye(Berberine chloride) and anionic polyelectrolyte PSS(Polysodium 4-styrenesulfonate) in aqueous solution via electrostatic attraction. The corresponding results on multi-layer were characterized by UV-Vis absorbance measurements. The growth of multi-layer formed by the sequential interaction was also determined. The findings measured by UV-Vis spectrophotometer showed that the bilayer deposition characteristic was linear and highly reproducible from layer to layer.

Photolysis of Diazotetracyanocyclopentadiene and Identification of Carbene Intermediate (디아오화합물의 광분해반응과 카르벤 중간체의 확인)

  • Kim, Min-Sik;Eom, Tae-Seop;Seong, Dae-Dong
    • The Korean Journal of Food And Nutrition
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    • v.7 no.1
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    • pp.29-35
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    • 1994
  • Photolysis of diazotetracyanocyclopentadiene has been investigated by means of IR and UV-vis spec troscopy in Ar matrix. Parent carbene is produced in low yield and could be detected by UV-vis spectroscopy and IR spectroscopy. The carbene produced from the diazo compound is very photolabile and also decay thermally at temperature as low as 10K. When the diazo compound is photolyzed the Arrhenius plots show a tunneling effect that is not shown as non linearity.

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Spectrophotometric and Electrochemical Study of Cu2+-Selective Azocalix[4]arene Bearing p-Carboxyl group

  • Kim, Tae Hyun;Kim, Jong Seung;Kim, Hasuck
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3377-3380
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    • 2013
  • The spectrophotometric and electrochemical properties of tetraazo(p-carboxy)phenylcalix[4]arene (p-CAC) in the presence of various metal ions were investigated by UV/Vis spectroscopy and voltammetry in $CH_3CN$. p-CAC showed selective color changes to $Cu^{2+}$ over other metal ions from light orange to colorless, in accordance with hypsochromic shift in UV/Vis spectra. Voltammetric measurements also showed high selectivity for $Cu^{2+}$.