• Title/Summary/Keyword: S-chemistry

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Dichloro, Alanine and S-Methylcysteine Cobalt (III) Complexes of Ethylenediamine-N,N$^\prime$-di-$\alpha$-isobutyric Acid

  • Jun, Moo-Jim;Park, Chang-Woo;Park, Youn-Bong;Cheon, Jin-Woo;Choi, Sung-Rack
    • Bulletin of the Korean Chemical Society
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    • v.11 no.4
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    • pp.354-357
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    • 1990

  • Synthesis of dichloro cobalt (Ⅲ) complexes of a flexible $N_2O_2-type$ tetradentate ligand, ethylenediamene-N,N'-di-${\alpha}$-isobutyric acid (eddib), has yielded two geometrical isomers, s-cis-$(Co(eddib)Cl_2)- and uns-cis-(Co(eddib)Cl_2)-.$ A series of substitution reactions, $(Co(eddib)Cl_2)^- {\to} (CO(eddib)Cl H_2O) {\to} (Co(eddib)CO_3)^- {\to} (Co(eddib(H_2O)_2)^+$ have been run for each of the two geometrical isomers. The reaction between the s-cis-(Co(eddib)Cl_2)^-$ complex and L-alanine (L-als) or S-methyl-L-cysteine (L-mcy) gave the meridional s-cis-[Co(eddib)(aa)) (aa = L-ala or L-mcy) complex. The S-methyl-L-cysteine was found to coordinate to cobalt (Ⅲ) ion via the nitrogen and oxygen donor atoms.

  • https://doi.org/10.5012/bkcs.1990.11.4.354 인용 PDF

New Low-Band Gap 2D-Conjugated Polymer with Alkylthiobithiophene-Substituted Benzodithiophene for Organic Photovoltaic Cells

  • Park, Eun Hye;Ahn, Jong Jun;Kim, Hee Su;Kim, Ji-Hoon;Hwang, Do-Hoon
    • Journal of the Korean Chemical Society
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    • v.60 no.3
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    • pp.194-202
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    • 2016

  • Two conjugated semiconducting copolymers consisting of 4,7-bis(4-(2-ethylhexyl)-2-thiophene)-2,1,3-benzothiadiazole (DTBT) and benzo[1,2-b:4,5-b']dithiophene with 5-(2-ethylhexyl)-2,2'-bithiophene (BDTBT) or 5-(2-ethylhexylthio)- 2,2'-bithiophene (BDTBT-S) were designed and synthesized as donor materials for organic photovoltaic cells (OPVs). Alkylthio-substituted PBDTBT-S-DTBT showed a higher hole mobility and lower highest occupied molecular orbital (HOMO) energy level (by 0.08 eV) than the corresponding alkyl-substituted PBDTBT-DTBT. An OPV fabricated using PBDTBT-S-DTBT showed higher VOC and JSC values of 0.83 V and 7.56 mA/cm2, respectively, than those of a device fabricated using PBDTBT-DTBT (0.74 V) leading to a power conversion efficiency of 2.05% under AM 1.5G 100 mW/cm2 illumination.

  • https://doi.org/10.5012/jkcs.2016.60.3.194 인용 PDF KSCI KPUBS HTML

Solvent Effect on the Nature of the Metallamacrocycles Formed: Formation of Octanuclear and Dodecanuclear Manganese Metalladiazamacrocycles

  • John, Rohith P.;Lee, Kyung-Jin;Lee, Kyung-Jae;Park, Mi-Ra;Lah, Myoung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.28 no.11
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    • pp.2009-2014
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    • 2007

  • The aminolysis of diphenyl thiophosphinic chloride (2) with substituted anilines in acetonitrile at 55.0 oC is investigated kinetically. Kinetic results yield large Hammett ρX (ρnuc = ?3.97) and Bronsted βX (βnuc = 1.40) values. A concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state is proposed on the basis of the primary normal kinetic isotope effects (kH/kD = 1.0-1.1) with deuterated aniline (XC6H4ND2) nucleophiles. The natural bond order charges on P and the degrees of distortion of 42 compounds: chlorophosphates [(R1O)(R2O)P(=O)Cl], chlorothiophosphates [(R1O)(R2O)P(=S)Cl], phosphonochloridates [(R1O)R2P(=O)Cl], phosphonochlorothioates [(R1O)R2P(=S)Cl], chlorophosphinates [R1R2P(=O)Cl], and chlorothiophosphinates [R1R2P(=S)Cl] are calculated at the B3LYP/ 6-311+G(d,p) level in the gas phase.

  • https://doi.org/10.5012/bkcs.2007.28.11.2009 인용 PDF KSCI

Enantiomeric Resolution of α-Amino Acid Derivatives on Two Diastereomeric Chiral Stationary Phases Based on Chiral Crown Ethers Incorporating Two Different Chiral Units

  • Kim, Hee-Jin;Choi, Hee-Jung;Cho, Yoon-Jae;Hyun, Myung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1551-1554
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    • 2010

  • Two diastereomeric chiral stationary phases (CSPs) were applied to the liquid chromatographic resolution of various racemic ${\alpha}$-amino methyl esters, ${\alpha}$-amino N,N-diethylamides and ${\alpha}$-amino N-propylamides. The CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (R,R)-tartaric acid unit as chiral barriers did not show any chiral recognition. In contrast, the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit as chiral barriers was found to show excellent chiral recognition especially for the two enantiomers of ${\alpha}$-amino N-propylamides. Some of ${\alpha}$-amino methyl esters and ${\alpha}$-amino N,N-diethylamides were also resolved on the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit. From these results it was concluded that the two chiral units composing the diastereomeric CSPs can show "matched" or "mismatched" effect on the chiral recognition according to their absolute stereochemistry.

  • https://doi.org/10.5012/bkcs.2010.31.6.1551 인용 PDF KSCI