• Title/Summary/Keyword: HOMO

Search Result 561, Processing Time 0.026 seconds

Prediction of Radical Reaction Positions in PAHs by Semi-Empirical Calculation (반경험적인 계산에 의한 다환방향족탄화수소류의 라디칼 반응위치 예측)

  • Lee, Byung-Dae
    • Journal of Environmental Science International
    • /
    • v.19 no.6
    • /
    • pp.755-759
    • /
    • 2010
  • Each four polycyclic aromatic hydrocarbons (PAHs) was reacted with OH radical at $1.5{\AA}$ distance by CAChe MOPAC 2000 program. These results were compared to those reported experimental results. Reaction positions of all four PAHs corresponded with predicted positions in which ${\Delta}$E(HOMO-LUMO) was approximately 4.7. Finally oxygen of OH radical combined with PAH and quinone form of products were produced. These results indicate that the proposed determining the ${\Delta}$E(HOMO-LUMO) can be effectively applied to predict reaction position of recalcitrant compounds such as dioxins, PCBs, POPs, and etc.

Synthesis of Steroidal Nitrosoureas as Antitumor Activity

  • Kim, Jack-C.;Choi, Soon-Kyu;Moon, Sung-Hwan
    • Archives of Pharmacal Research
    • /
    • v.9 no.4
    • /
    • pp.215-217
    • /
    • 1986
  • Steroidal nitrosoureas have been synthesized and their antitumor activity on L 1210 cells was evaluated, N-(2-Chloroethyl)-N-nitrosocarbamoyl-3-aza-A-homo-5$\alpha$-cholestane (5a) showed significantly low $ED_{50}$ value of 1.6 $\nu$g/ml whose activity is equivalent to that of methyl-CCNU ($ED_{50}$ = 1.7 mg/ml).

  • PDF

Synthesis and Spectroscopic Analysis of Trans-A2B2 Metallo-Porphyrin Derivatives as Heterojunction Modulator for Organic Solar Cell

  • Jeon, Yea-Sel;Hwang, Kwang-Jin
    • Rapid Communication in Photoscience
    • /
    • v.3 no.3
    • /
    • pp.59-60
    • /
    • 2014
  • The trans-$A_2B_2$ porphyrin and Ni-porphyrin derivatives were synthesized by Suzuki coupling of bromoporphyrin with arylborate as a key step. The band gaps of those complexes were measured from their absorption, emission and cyclic voltammetric data. All the LUMO energy level of porphyrin derivatives is lower than that of P3HT, and the HOMO energy level is evaluated higher than the HOMO of PCBM.

Cytogenetic Studies of Codonopsis lanceolata Benth. Et. Hook. Geographical Variety of Somatic Chromosomes in Local Type (더덕 ( Codonopsis lanceolata ) 의 세포유전학적 연구 II. 지역별 염색체형의 차이)

  • 윤의수
    • Korean Journal of Plant Resources
    • /
    • v.5 no.1
    • /
    • pp.31-35
    • /
    • 1992
  • The somatic chromosome numbers were counted to be 2n = 16 of Codonopsis lanceolata. Chromosomes 2 and 7 of Sokrisan and Koheung II has a hetero satellite on short arm. Chromosome 5 of Bakwoonsan showed homo satllite on short arms. Short arms of chromosomes 1 and 5 has homo satellite and short arms of chromosomes 2 and 7 has hetero satellite of Jilin.

  • PDF

DFT and Time-dependant DFT Investigation of eLectronic Structure, Phosphorescence and Electroluminescence Properties of Iridium (III) Quinoxaline Complexes (Iridium (III) quinoxaline 착물의 전자 구조, 인광 및 전기 발광 특성에 대한 DFT 및 시간-의존 DFT 연구)

  • Zhou, Xiao-Qing;Li, Ying;Sun, Yan-Bo;Zhang, Hong-Xing
    • Journal of the Korean Chemical Society
    • /
    • v.55 no.3
    • /
    • pp.354-363
    • /
    • 2011
  • Quantum-chemistry study was explored to investigate the electronic structures, absorption and phosphorescence mechanism, as well as electroluminescence (EL) properties of three red-emitting Ir(III) complexes, $(fpmqx)_2Ir$(L) {fpmqx=2-(4-fluorophenyl)-3-methyl-quinoxaline; L=triazolylpyridine (trz) (1); L=picolinate (pic) (2) and L=acetylacetonate (acac) (3)}. The calculated results show that the HOMO distribution for 1 is mainly localized on trz moiety due to its stronger ${\pi}$-electron acceptor ability, and HOMO for 2 and 3 is the combination of Ir d- and phenyl ring ${\pi}$-orbital. The higher phosphorescence yields and differences among 1-3 are investigated in this paper. In addition, the reasons of higher EL efficiency of 2 than 1 and 3 have been rationalized.

The Studies on Molecular Geometries and Electronic Structures of Substituted meso-Catecholic Porphyrins: DFT Methods and NSD

  • Park, Seung-Hyun;Kim, Su-Jin;Kim, Jin-Dong;Park, Sung-Bae;Huh, Do-Sung;Shim, Yong-Key;Choe, Sang-Joon
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.6
    • /
    • pp.1141-1148
    • /
    • 2008
  • Geometry optimizations and electronic structure calculations are reported for meso-tetraphenyl porphyrin (TPP) and a series of meso-substituted catecholic porphyrins (KP99150, KP99151, KP99152, KP99153, and KP99090) using density functional theory (DFT). The calculated B3LYP//RHF bond lengths are slightly longer than those of LSDA//RHF. The calculated electronic structures clearly show that TPP and meso-catecholic group contribute to π-electron conjugation along porphyrin ring for HOMO and LUMO, significantly reduced the HOMO-LUMO gap. The wavelength due to B3LYP energy gaps is favored with experimental value in Soret (B), and LSDA energy gaps are favored with experimental value in visible bands (Q). The electronic effect of the catecholic groups is to reduced energies of both the HOMOs and LUMOs. However, the distortion of porphyrin predominantly raises the energies of the HOMOs, so the net result is a large drop in HOMO and smaller drop in LUMO energies upon meso-substituted catecholic group of the porphyrin macrocycle as shown in KP99151 and KP99152 of Figure 5(a). These results are in reasonable agreement with normal-coordinate structural decomposition (NSD) results. The HOMO-LUMO gap is an important factor to consider in the development of photodynamic therapy (PDT).

A Study on the Application of Chemical Grouting Method for Aging Reservoir Reinforce According to the Change of Binder and Using Water (결합재 및 사용수 변화에 따른 노후저수지 보강용약액주입공법 적용에 관한 연구)

  • Song, Sang-Hwon;Seo, Se-Gwan
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.21 no.4
    • /
    • pp.45-52
    • /
    • 2019
  • Chemical grouting method is mainly used for construction of dams and reservoirs, stabilization and reinforcement of slopes, reinforcement of soft grounds such as embankments, dredging and landfills, the order of earthquake response method, and the reinforcement of structures. Recently, it is widely applied in construction sites such as highways, airfields, high-speed railways, subsea facilities, port construction works, tunnels, and subway works. As such, the demand for grouting continues to increase. The development of the grouting method was focused on increasing the strength of the ground, and the development of the chemical additives, the injection device, and the stirring device were mainly performed. But ordinary portland cement used for grouting is a product that consumes natural resources such as limestone, generates a large amount of greenhouse gases, consumes a large amount of energy sources, and it is time to develop products and new methods to replace them. In this study, Ordinary Portland Cement and New Grouting Binder (circulating fluidized bed boiler fly and blast furnace slag) were compared and analyzed by the following test. Homo-gel strength and homo-gel time, water quality analysis of the water used and soil contamination process tests of homo-gel samples were performed. In the case of NGB, when Using water is used as the reservoir water, the strength measured smaller than that of the other water. However, it shows about 2.5 times greater than the homo-gel compressive strength applied to OPC (7-day, reservoir water), so there is no problem with water quality when applied.

Electrochemical and Spectrum Properties of 2,7-Naphthalene Ligand Compounds (2,7-Naphthalene Ligand Compounds의 전기화학 및 분광학적 특성)

  • Choi, Don-Soo;Kim, Mu-Young;Hyung, Kyung-Woo
    • Korean Journal of Materials Research
    • /
    • v.19 no.9
    • /
    • pp.510-515
    • /
    • 2009
  • The compound of 2,6-Bis[(9-phenylcarbazolyl)ethenyl]naphthalene (BPCEN-1), 2-[6-{1-Cyano-2-(9-phenylcarbazoly)vinyl}naphthyl]-3-(9-phenylcarbazolyl)acrylonitrile (BPCEN-2), 2,6-Bis[{4-(1-naphthy l)phenylamino} styrenyl] naphthalene (BNPASN-1), 2-[6-{1-Cyano-2-(naphthylphenylaminophenyl) vinyl}naphthyl]-3-(naphthylphenylaminophenyl)acrylonitrile (BNPASN-2) was analyzed electrochemically and spectroscopically and can be obtained by bonding phenylcarbazolyl, naphthylphenylaminophenyl and -CN ligands to 2,7-naphthalene. The electrochemical and spectroscopic study resulted in the P-type (BPCEN-1, BNPASN-1) being changed to N-type (BPCEN-2, BNPASN-2) according to -CN bonding despite having the same structure. The value of band gap(Eg) was revealed to be small as HOMO had shifted higher and LUMO lower. The Eg value for naphthylphenylaminophenyl ligand was reduced because it has a smaller HOMO/LUMO value than that of phenylcarbazolyl from a structural perspective. The electrochemical HOMO/LUMO values for BPCEN-1, BPCEN-2, BNPASN-1, BNPASN-2 were measured to be 5.55eV / 2.83eV, 5.73eV / 3.06eV, 5.48eV / 2.78eV, and 5.53eV / 2.98eV, respectively. By -CN ligand, the UV max, Eg and PL max were shifted to longer wavelength in their spectra and the luminescence band could be also confirmed to be broad in the photoluminescence (PL) spectrum.

Genetic Polymorphisms of the Serum Protein Locus in Korean Native Goats (한국재래산양 혈청단백질 좌위의 유전적 다형현상에 관한 연구)

  • 김계웅
    • Korean Journal of Animal Reproduction
    • /
    • v.19 no.3
    • /
    • pp.235-241
    • /
    • 1995
  • These experiments were carried out to find genetic polymorphisms of Serum protein like Pre-albumin(Pr), Albumin(Al) and Transferrin(Tf), and establish preservation of pure pedigree in Korean Native Goats(KNG). Their serum was collected and examined from the total of 74 KNG that raised in Tang Jin district, Chungnam-province. They were biochemically analysed by polyacrylamide gel(7.5%) electrophoresis(PAGE) in order to estimate the frequencies of genotypes and alleles existing on each trait locus. The results obtained in these experiments were summarized as follows ; 1. In the serum Pre-albumin(Pr) locus, the frequencies of genotypes for hetero AB and homo BB observed were 55.4%, and 44.6%, respectively. While homo AA was not found in the Pr locus. The frequencies of gene in PrA and PrB were 0.723 and 0.277, respectively. Accordingly, the Pr loci were assumed to be controlled by alleles PrA and PrB. 2. The frequencies of genotypes of homo BB and hetero AB detected in Albumin(Al) locus were 75.7% and 24.3%, respectively. However, AA type was not observed in the Al locus. The gene frequencies of AlA an AlB were 0.879 and 0.121, respectively. Also, the Al loci were considered to be controlled by alleles AlA and AlB. 3. The frequencies of genotypes for hetero AD and homo DD found in Transferrin (Al) locus were 79.7% and 20.3%, respectively. Whereas, homotype AA was not detected in this locus. The gene frequencies of TfA and TfD were 0.399 and 0.601, respectively. Therefore, the serum Tf loci were assumed to be controlled by alleles Tfa and Tfd.

  • PDF