• Title/Summary/Keyword: Molecular orbital

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Theoretical Calculations of Metol as Corrosion Inhibitor of Steel (강철 부식 방지제인 메톨에 대한 이론적 계산)

  • Gece, Gokhan
    • Journal of the Korean Chemical Society
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    • v.53 no.6
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    • pp.671-676
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    • 2009
  • Described here for the first time is an investigation on geometrical and electronic molecular structure of metol (N-methyl-p-aminophenol sulphate) as corrosion inhibitor of steel using density functional theory (DFT) calculations. Quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap ((${\Delta}E$), Mulliken charges (($q_M$) and natural atomic (($q_n$) charge have been calculated both for gas and aqueous phases by using B3LYP/6-31G+(d,p) basis set. The relation between the inhibition efficiency and quantum chemical parameters have been discussed in order to elucidate the inhibition mechanism of the title compound.

Comparison of the Fatty Acid Composition and Small Molecular Metabolites between Yanjin Blackbone Chicken and Piao Chicken Meat

  • Rong Jia;Wen Xun;Guozhou Liao;Yuan Yang;Guiying Wang
    • Food Science of Animal Resources
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    • v.43 no.6
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    • pp.975-988
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    • 2023
  • The fatty acid composition and small molecular metabolites in breast and leg meat of Yanjin blackbone chickens (YBC) and Piao chickens (PC) were detected by gas chromatography-mass spectrometry and liquid chromatography-quadrupole static field orbital trap mass spectrometry. Thirty-two fatty acids were detected, and the total fatty acid content of PC was significantly higher than that of YBC (p<0.05). Oleic acid, linoleic acid, palmitic acid, stearic acid, and arachidonic acid were the main fatty acids in the two chicken varieties, and the composition of fatty acids in the two varieties were mainly unsaturated fatty acids, being more than 61.10% of the total fatty acids. Meanwhile, 12 and 16 compounds were screened out from chicken legs and chicken breasts of YBC and PC, respectively, which had important contributions to the differences between groups.

Calculation on Effect of Impurity Addition on Electronic State of $MnO_2$ Oxide Semiconductor by First Principle Moleculat Orbital Method (제1원리 분자궤도계산법에 의한 $MnO_2$ 산화물 반도체의 전자상태에 미치는 불순물 첨가 효과의 계산)

  • Lee, Dong-Yoon;Kim, Bong-Seo;Song, Jae-Sung;Kim, Hyun-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.99-102
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    • 2003
  • The electronic structure of ${\beta}-MnO_2$ having impurities in the site of Mn was theoretically investigated by $DV-X_{\alpha}$ (the discrete variation $X{\alpha}$) method, which is a sort of the first principle molecular orbital method using Hatre-Fock-Slater approximation. The used cluster model was $[Mn_{14}MO_{56}]^{-52}$ (M = transient metals). Madelung potential and spin polarization were considered for more exact calculations. As results of calculations, the energy levels of all electron included in the model were obtained. The energy band gap and positions of impurity levies were discussed in association with impurity 34 orbital that seriously affect electrical properties of $MnO_2$. It was shown that the energy band gap decreased with the increase of the atomic number of transient metal impurity.

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Syntheses and Characterisitics of New Photochromic Spiroxazine Dyes (새로운 광변색성 Spiroxazine색소의 합성과 특성)

  • 김성훈
    • Journal of the Korean Graphic Arts Communication Society
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    • v.12 no.1
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    • pp.159-168
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    • 1994
  • The Aggregation State of thin vapor deposite Film made by Cyanine Dye were changed into Monomeric molecular state(M) and Dimeric Aggregation(D) at the acidic treatment, into reversible H-Aggregation (H) at alkalic gas or heat treatment. Photo-electric properties were higher H than D and M, this stats were effective in enhancing Photoelectric-conversion characteristic. Substitute group of Meso-Position being stronger electronic Donors, Electronic density is higher and Electric conductivity is enhanced, we confirmed Oscillator Strength calculated by PPP-Molecular Orbital Calculation and Absorption Spectra at solvent stats were agreed good.

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The Dipole Moment Derivatives of Methane

  • Kim, Kwan;Park, Cheol-Woo
    • Bulletin of the Korean Chemical Society
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    • v.7 no.5
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    • pp.380-384
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    • 1986
  • The infrared intensities of $CH_{4}$ and $CD_{4}$ are analyzed. The experimental dipole moment derivatives thus obtained are compared with corresponding values from the molecular orbital calculations. The theoretical results are analyzed for the charge-charge flux-overlap(CCFO) electronic contributions to the dipole derivatives.

Semiempirical MO Calculation of Hetero Atom Three-Membered Ring Compounds(II)${\cdot}$N-Nitroso-azirine and-diaziridine

  • Ki Woon Hwang
    • Bulletin of the Korean Chemical Society
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    • v.12 no.3
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    • pp.328-331
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    • 1991
  • Fully optimized MNDO molecular orbital calculations are performed for N-nitroso-azirine (Ⅰ) and-diaziridine (Ⅱ). The ground state geometries show the nonplanar configuration around the imino nitrogen. The nitroso group rotational energy barriers and the ring inversion energy barriers are also discussed.

Calculation of the Dipole Moments for Transition Metal Complexes by Valence Bond Method (I). Calculation of the Dipole Moments for Octahedral $[M(III)O_3S_3]$ Type Complexes [M(III) = V(III), Cr(III), Mn(III), Fe(III), Co(III), Ru(III), Rh(III) and Os(III)] (원자가 결합법에 의한 전이원소 착물에 대한 쌍극자모멘트의 계산 (제1보). 팔면체 $[M(III)O_3S_3]$ 형태 착물의 쌍극자모멘트의 계산 [M(III) = V(III), Cr(III), Mn(III), Fe(III), Co(III), Ru(III), Rh(III) 및 Os(III)])

  • Sangwoon Ahn;Jeoung Soo Ko
    • Journal of the Korean Chemical Society
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    • v.23 no.4
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    • pp.198-205
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    • 1979
  • A valence bond method of calculation of the dipole moments for octahedral $(M(III)0_3S_3)$ type complexes are developed, using $d^2sp^3 $hybrid orbitals of the central metal ions and the single basis set orbital of ligands. (M (III) =V (III), Cr (III), Mn (III), Fe (III), Co (III), Ru (III), Rh (III) and OS (III)). In this method the mixing coefficient of the valence basis sets for the central metal ion with the appropriate ligand orbitals is not required to be the same, differently from the molecular orbital method. The valence bond method is much more easier to calculate the dipole moments for octahedral complexes than the approximate molecular orbital method and the calculated results are also in the range of the experimental vaues.

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