• Title/Summary/Keyword: IR spectra

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Synthesis and Characterization of Cobalt(II)/(III), Nickel(II) and Copper(II) Complexes of New 14, 15 and 16-Membered Macrocyclic Ligands

  • El-Tabl, Abdou Saad
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1757-1763
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    • 2004
  • A new series of nickel(II), cobalt(II)/(III) and copper(II) complexes of 14, 15 and 16-membered of macrocyclic ligands have been prepared and characterized by elemental analyses, IR, UV-VIS and $^1H-NMR$ spectra, magnetic susceptibilities, conductivities, DTA and ESR measurements. Molar conductances in DMF solution indicate that, the complexes are nonelectrolytes except (9-12) complexes. The electronic spectra show that, all complexes are square planar or distorted octahedral geometry. The ESR spectra of solid complexes (4), (8) and (11) show square planar of axial type symmetry $(d_{x2-y2})$ with considerable covalent bond character. However, complex (12) shows a spectrum of octahedral geometry with $d_{z2}$ ground state. Complex (12) shows exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.

Structural Dynamics of Myoglobin Probed by Femtosecond Infrared Spectroscopy of the Amide Band

  • Kim, Seong-Heun;Jin, Geun-Young;Lim, Man-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.10
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    • pp.1470-1474
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    • 2003
  • The dynamics of the tertiary conformation of myoglobin (Mb) after photolysis of carbon monoxide was investigated at 283 K solution by probing amide I and II bands using femtosecond IR absorption spectroscopy. Time-resolved spectra in the amide region evolve with 6-12 ps time scale without noticeable subpicosecond dynamics. The spectra measured at 100 ps delay after photolysis is similar to the difference FTIR spectrum at equilibrium. Time-resolved spectra of photoexcited Mb evolve modestly and their amplitudes are less than 8% of those of photolyzed MbCO, indicating that thermal contribution to the spectral evolution in the amide region is negligible. These observations suggest that the conformational relaxation ensuing photolysis of MbCO be complex and the final deoxy protein conformation have been substantially formed by 100 ps, probably with 6- 12 ps time constant.

A STUDY OF ISO SPECTRA FOR HERBIG Ae/Be STARS

  • Suh, Kyung-Won;Kim, Mi-Ryang;Baek, Ji-Hye
    • Journal of Astronomy and Space Sciences
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    • v.19 no.4
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    • pp.255-262
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    • 2002
  • We present the infrared spectra of Herbig Ae/Be stars including the Infrared Space Ob-servatory (ISO) data. To investigate the overall properties of their circumstellar dust envelope and/or disk, we combine the IR spectra with photometric data ranging from the UV through the optical into the sub-mm region. We study the general characteristics of the spectral energy distributions using simple analysis. We plot the positions on the HR-diagram to compare with the theoretical pre-main-sequence evolution tracks.

The out-of-plane Band Contour of Dichloroborane Molecules

  • Lee, Kuk-Haeng;Kim, Ja-Hong;Sohn, Sung-Ho;Shim, Sang-Chul
    • Bulletin of the Korean Chemical Society
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    • v.8 no.3
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    • pp.147-149
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    • 1987
  • The out-of-plane bending, vibrational-rotational FT-IR spectra of dichloroborane molecule were analyzed. The band centers are 785.992, 785.723, 647.217, and 646.997 $cm^{-1}$ and centrifugal distortion constants are $2.2{\times}10^{-6},\;5.5{\times}10^{-6},\;0.2{\times}10^{-6}$, and $0.7{\times}10^{-6}cm^{-1}$ for $H^{11}B^{35}Cl_2$, $H^{11}B^{35}Cl^{37}Cl$, $D^{11}B^{35}Cl_2$, and $D^{11}B^{35}Cl^{37}Cl$, respectively. The theoretical spectrum of $D^{11}B^{36}Cl_2$ was plotted to conform the molecular constants and the rotational constants for the first excited vibrational state of this molecule were A' = 1.165932, B' = 0.106166, and C' = 0.097229 $cm^{-1}$. The calculated spectra were in good agreement with the observed spectra.

Spectroscopic Evaluation on the Chemical Damage of Hair by Hydrogen Peroxide (과산화수소에 의한 모발의 화학적 손상에 관한 분광학적 평가)

  • Ha, Byung-Jo
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.579-581
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    • 2011
  • Spectroscopic evaluation of hair chemical damage was performed by SEM/EDS, CLSM, and FT-IR spectroscopy. In SEM/EDS, hydrogen peroxide treated hair showed the loose packing of surface scales, lower ratio of sulfur element and higher ratio of oxygen atom. In the optical single section by using CLSM, high fluorescent intensity appeared in untreated hair. However, in case of treated hair, low fluorescent intensity appeared. This results the aromatic amino acids which can be autofluorescent were more abundant than bleached hair. FT-IR spectra showed that cysteic acid band intensity was increased by performing the bleaching treatments. These results indicate that the oxidative damage cleaves the S-S bond and results in the lower working force of hair fiber.

A Study on Coumarins of Angelica decursiva (바디나물 열매의 Coumarin 성분 연구(I))

  • Yook, Chang-Soo
    • Korean Journal of Pharmacognosy
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    • v.6 no.3
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    • pp.149-150
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    • 1975
  • Silicagel colum chromatography of the ether extract of the fruits of Angelica decursiva $F_R$. et SAV. gave four crystalline products of coumarins and one steroid. The following furocoumarins and ${\beta}-sitosterol$ were identifed by UV, IR, NMR spectra and physicochemical tests: ${\beta}-sitosterol$, iso-imperatorin, imperatorin, bergapten, umbelliferone.

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