• Title/Summary/Keyword: HOMO

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Synthesis, Characterization and Determination of HOMO-LUMO of the Substituted 1,3,5-Triazine Molecule for the Applications of Organic Electronics

  • Pakkath, Rajeesh;Reddy, Eeda Koti;Kuriakose, Sheena;Saritha, C;Sajith, Ayyiliath M;Karuvalam, Ranjith Pakkath;Haridas, Karickal Raman
    • Journal of the Korean Chemical Society
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    • v.63 no.5
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    • pp.352-359
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    • 2019
  • The most important parameter of organic molecules for energy harvesting application focuses mainly on their band gap (HOMO-LUMO). In this report, we synthesized differently substituted 1,3,5-triazine based organic molecule which on future processing can be used in organic electronics like solar cells and OLED's. The energy gap of the synthesized novel analogue was calculated using cyclic voltammetry, UV-Visible spectroscopy and compared with density functional theory (DFT) studies.

Study on the characteristics of grout material using ground granulated blast furnace slag and carbon fiber

  • Kim, Daehyeon;Park, Kyungho
    • Geomechanics and Engineering
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    • v.19 no.4
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    • pp.361-368
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    • 2019
  • This study aims to evaluate the applicability of a grout material that is mixed with carbon fiber, biogrout, ground granulated blast furnace slag (GGBS) powder and cement. Uniaxial compressive strength tests were performed on homo-gel samples at days of 1, 3, 7, 14 and 28. In addition, the variation of permeability with the mixing ratios was measured. Based on the uniaxial compressive strength test, it was confirmed that the uniaxial compressive strength increased by 1.2times when carbon fiber increased by 1%. In addition, as a result of the permeability test, it was found that when the GGBS increased by 20%, the permeability coefficient decreased by about 1.5times. Therefore, the developed grout material can be used as a cutoff grouting material in the field due to its strength and cut-off effect.

Synthesis and Band Gap Analysis of Meso-Arylporphyrins Containing Exclusively Electron Donating or Withdrawing Groups

  • Min Su Kang;Kwang-Jin Hwang
    • Journal of the Korean Chemical Society
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    • v.67 no.3
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    • pp.175-180
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    • 2023
  • Tetra-aryl substituted A4-type porphyrins (TP, TD, TA) and trans-A2B2 porphyrins (DDP1, AAP1) with electron-donating or withdrawing groups were synthesized. The band gap energy of those porphyrins was calculated from their UV-Vis spectra and CV data. With an electron-withdrawing group, the band gap energy of porphyrin TA increased via the LUMO energy up. Meanwhile, the introduction of an electron-donating group decreased the band gap of porphyrin by HOMO level up as as in the case of porphyrin TD. The band gap (2.19-2.28 eV) of metalloporphyrin PP-Ni was greater than those (1.81-2.06 eV) of non-metalloporphyrins PP due to the LUMO level up.

The Importance of $\pi$-Nonbonded Secondary Orbital Interaction on the Stereoselectivity in the (4+2) Cycloaddition Reactions of Allene Compounds (알렌화합물의 (4+2) 고리화반응에서 입체 선택성에 대한 $\pi$-비결합 2차 궤도함수 상호작용의 중요성)

  • Ikchoon Lee;Keun Bae Rhyu;Byung Choon Lee
    • Journal of the Korean Chemical Society
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    • v.31 no.2
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    • pp.133-142
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    • 1987
  • Stereoselectivities of (4+2) cycloaddition reactions of cyclopentadiene with the methyl-substituted allenic acids and esters were investigated by application of $\pi$-nonbonded interaction ($\pi$-NBI) theory. 2-FMO method has been found to be adequate for determination of endo selectivities of diene(LUMO)-dienophile (LUMO) interaction in the thermal reactions and diene (HOMO)-dienophile (LUMO) interaction in the Lewis acid catalyzed reactions. $\pi$-isoconjugate diene structure was formed by through-bond interaction of allene moiety with methyl group in the cumulated diene system; the methyl substituent acts as a conjugative chain and causes inter-level narrowing effect of the FMO's. In dienophiles which do not form $\pi$-isoconjugate diene system, methyl group acts merely as an electron donating group. In thermal reactions, the stereoselectivities are controlled by $\pi$-nonbonded secondary orbital interaction ($\pi$-NSOI) of methyl substituent, which behaves similarly as an ethylene molecule.

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Expression of Lysozyme and Aquaporins mRNA in Otitis Media

  • Kang, Sung-Ho;Lim, Dae-Joon;Kim, Bo-Hyung;Rhu, Myung-Sang;Kang, Shin-Seok
    • Biomedical Science Letters
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    • v.24 no.2
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    • pp.116-124
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    • 2018
  • Lysozyme is known as a key substance of the innate immunity and have antibacterial effect in the mucosal tissues, especially middle ear. Aquaporin (AQP) functions as water movement in the tissue and has been expected to be participated in the inflammatory responses. In the present study, we investigated to reveal association of lysozymes and AQPs in otitis media. The gene expression of lysozyme genes, homo sapiens lysozyme (hLYZ), homo sapiens lysozyme M (hLYZ M), and homo sapiens lysozyme G like-2 (hLYGH), and AQP genes (AQP 0 - AQP 12) were measured from postauricular skin, mastoid mucosa, inflamed mastoid mucosa, and middle ear mucosa. The hLYZ, hLYZ M and hLYGH gene were expressed in mastoid mucosa, inflamed mastoid mucosa, middle ear mucosa. Of AQP genes, all AQP gene except AQP 3 gene were expressed in the tissue of middle ear. Among them, AQP 4, AQP 8, AQP 9, AQP 10, AQP 11 and AQP 12 were highly expressed in the inflamed mastoid mucosa and normal mastoid mucosa (P<0.001). Interestingly, expression levels of AQP 4, AQP 9, and AQP 12 gene were significantly higher in the inflamed mastoid mucosa compared to normal middle ear mucosa (P<0.05). These results suggest that lysozyme and AQPs could be associated with inflammatory response in the middle ear.

Efficiency of RAPD and ISSR Markers in Differentiation of Homo- and Heterokaryotic Protoclones of Agaricus bisporus

  • Mahmudul, Islam Nazrul;Bian, Yin-Bing
    • Journal of Microbiology and Biotechnology
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    • v.20 no.4
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    • pp.683-692
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    • 2010
  • Morphologically, nine different slow-growing protoclones were screened from regenerated protoplasts of heterokaryotic Agaricus bisporus. As such, the present study is the first report on differentiating homo- and heterokaryotic protoclones using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Among 80 primers tested, the seven ISSR and seven RAPD primers selected for the analysis generated a total of 94 ISSR and 52 RAPD fragments, respectively. The ISSR fingerprinting also detected more polymorphic loci (38.29%) than the RAPD fingerprinting (34.61%). A principal coordinate analysis (PCA) was employed to evaluate the resolving power of the markers as regards differentiating protoclones. As a result, the mean polymorphism information content (PIC) for each marker system (i.e., 0.787 for RAPD and 0.916 for ISSR) suggested that ISSR is more effective for determining polymorphisms. The dendrograms constructed using RAPD, ISSR, and an integrated RAPD and ISSR marker system were highly correlated with one another as revealed by a high Mantel correlation (r= 0.98). The pairwise similarity index values also ranged from 0.64 to 0.95 (RAPD), 0.67 to 0.98 (ISSR), and 0.67 to 0.98 (RAPD and ISSR), whereas the mean similarity index values of 0.82, 0.81, and 0.84 were obtained for the RAPD, ISSR, and combined data, respectively. As there was a good correspondence between the RAPD and ISSR similarity matrices, ISSR would appear to be an effective alternative to RAPD in the genetic diversity assessment and accurate differentiation of homo- and heterokaryotic protoclones of A. bisporus.

The Characteristices of the 4,4',4'-trifluoro-triazine as a hole Blocking Material in Electroluminescent Devices (전계발광 소자에서 정공 차단 물질로서의 4,4',4'-trifluoro-triazine의 특성)

  • Shin, Ji-Won;Shin, Dong-Muyng;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.2
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    • pp.120-125
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    • 2000
  • The tfTZ(4,4',4''-trifluoro-triazine) was used as a hole blocking material for the electroluminescent devices(ELDs) in this study. In general, the holes are outnumbered the electrons in hole transport and emitting layers because the hole transport is more efficient in most organic ELDs. The hole blocking layer are expected to control the excess holes to increase the recombination of holes and electrons and to decrease current density. The former study using the 2,4,6-triphenyl-1,3,5-triazine(TTA) as hole blocking layer showed that the TTA did not form stable films with vapor deposition technique. The tfTZ can generate stable evaporated films, moreover the fluorine group can lower the highest occupied molecular orbital(HOMO) level, which produces the energy barrier for the holes. The tfTZ has high electron affinities according to the data by the Cyclic-Voltammety(CV) method, which is developed for the measurement of HOMO and lowest occupied molecular orbital(LUMO) level of organic thin films. The lowered HOMO level is made the tfTZ to be applied for a hole blocking layer in ELDs. We fabricated multilayer ELDs with a structure of ITO/hole blocking layer(HBL)/hole transporting layer(HTL)/emitting layer/electrode. The hole blocking properties of this devices is confirmed from the lowered current density values compared with that without hole blocking layer.