• Title/Summary/Keyword: Spectroscopic characterization

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DNA and DNA-CTMA composite thin films embedded with carboxyl group-modified multi-walled carbon nanotubes

  • Dugasani, Sreekantha Reddy;Gnapareddy, Bramaramba;Kesama, Mallikarjuna Reddy;Ha, Tai Hwan;Park, Sung Ha
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.79-86
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    • 2018
  • Although the intrinsic characteristics of DNA molecules and carbon nanotubes (CNT) are well known, fabrication methods and physical characteristics of CNT-embedded DNA thin films are rarely investigated. We report the construction and characterization of carboxyl (-COOH) group-modified multi-walled carbon nanotube (MWCNT-COOH)-embedded DNA and cetyltrimethyl-ammonium chloride-modified DNA (DNA-CTMA) composite thin films. Here, we examine the structural, compositional, chemical, spectroscopic, and electrical characteristics of DNA and DNA-CTMA thin films consisting of various concentrations of MWCNT-COOH. The MWCNT-COOH-embedded DNA and DNA-CTMA composite thin films may offer a platform for developing novel optoelectronics, energy harvesting, and sensing applications in physical, chemical, and biological sciences.

Synthesis and Characterization of Phthalocyaninatometal (PcM, M=$Fe^{2+}$, $Co^{2+}$ Complexes with Monodenate Aromatic Isocyanide Ligands

  • 임윤묵;박하선;송수호;박찬조;유하일;이종기;양현수
    • Bulletin of the Korean Chemical Society
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    • v.20 no.6
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    • pp.701-704
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    • 1999
  • Metallophthalocyanines [PcM, Pc: phthalocyanine, M: Fe 2+ , Co 2+ ] were reacted with α-isocyanonaphthalene( α-in) and α-isocyanoanthracene (α-ia) to form monomeric complexes. The synthesis and coordination behaviour of the isocyanides as a ligand (L) are discussed. All the products were characterized by spectroscopic methods and instrumental analysis. The electrical conductivities of these complexes, which were not treated with dopant, were attributed to the metal-ligand electron delocalization in the PcML2 complexes. The complexes have an enlarged macrocycle where the π-electron back donating ability of PcM is stronger than the σ-electron coordinating ability of the isonitrile ligands. Their electrical conductivities were measured as σRT = 2.1×10 -9 ~3×10 -10 S/cm. Also thermal stability was investigated in this study.

Synthesis and Characterization of Bis(N,N-dimethyl-2-aminomethylthiophenium)Tetrahalocuprate(Ⅱ)

  • 정찬규;김영인;최성낙
    • Bulletin of the Korean Chemical Society
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    • v.17 no.9
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    • pp.845-849
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    • 1996
  • Bis(N,N-dimethyl-2-aminomethylthiophenium)tetrahalocuprate(Ⅱ) salt, (dmamtH)2CuCl4 and (dmamtH)2CuBr4 were prepared and characterized by spectroscopic (IR, UV-Vis, EPR, XPS), electrochemical method, and magnetic susceptibility measurement. The experimental results reveal that the compounds have pseudotetrahedral symmetry around copper(Ⅱ) site due to the steric hinderance of the bulky 2-(dimethylaminomethyl)thiophene in the complex. The N-H…Cl type hydrogen bonding is expected in (dmamtH)2CuCl4 from the XPS and IR data. Magnetic susceptibility data show that both of the compounds follow Curie-Weiss law in the range of 77-300 K with negative Weiss constant exhibiting antiferromagnetic interaction between copper(Ⅱ) ions in solid state.

Solid-State 51V NMR and Infrared Spectroscopic Study of Vanadium Oxide Supported on $ZrO_2-WO_3$

  • 손종락;이만호;도임자;배영일
    • Bulletin of the Korean Chemical Society
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    • v.19 no.8
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    • pp.856-862
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    • 1998
  • Vanadium oxide catalyst supported on ZrO2-WO3 was prepared by adding the Zr(OH)4 powder into a mixed aqueous solution of ammonium metavanadate and ammonium metatungstate followed by drying and calcining at high temperatures. The characterization of prepared catalysts was performed using solid-state 51V NMR and FTIR. In the case of calcination temperature at 773 K, for the samples containing low loading V2O5 below 18 wt % vanadium oxide was in a highly dispersed state, while for samples containing high loading V2O5 equal to or above 18 wt % vanadium oxide was well crystallized due to the V2O5 loading exceeding the formation of monolayer on the surface of ZrO2-WO3. The ZrV2O7 compound was formed through the reaction Of V2O5 and ZrO2 at 873 K and the compound decomposed into V2O5 and ZrO2 at 1073 K, which were confirmed by FTIR and 51V NMR.

Raman Spectroscopic Characterization of a Rod-Coil Liquid Crystalline Oligomer-LiCF₃SO₃ Complex

  • 유수창;한근옥;김동희;오남근;이명수;고석범;조인호
    • Bulletin of the Korean Chemical Society
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    • v.17 no.11
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    • pp.1004-1009
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    • 1996
  • The interactions between a rod-coil liquid crystalline oligomer, ethyl 4-[4'-oxy-4-biphenylcarbonyloxy]-4'-biphenylcarboxylate with poly(ethylene oxide) (DP=12) (12-4) and LiCF3SO3 have been characterized by using Raman spectroscopy. Band assignments were made comparing the spectrum of 12-4 with those of the poly(ethylene glycol) monomethyl ether(PEGME) (Mw=550) and the ethyl-4'-hydroxybiphenyl-4-carboxylate (EHBPC), which are the coil and mesogen analogues, respectively. Analyzing characteristic bands of the 12-4-salt complex, we have found that the bands belonging to the coil and mesogenic units are changed in both intensities and frequencies. The spectral changes were interpreted from the viewpoint of the complexation between 12-4 and the Li+ ion. However, the possibility that the spectral changes in the mesogenic unit are not due to the complexation with the Li+ ion, but due to the conformational changes by the intercalation of nondissociated LiCF3SO3, is not ruled out.

Synthesis and Characterization of Bis(5,6-dihydro-1,4-dithiin-2,3-dithiolato)nickel(II), nickel(III) and of Related Dialkyl Nickel(III) Dithiolene Complexes

  • 김영진;최성낙;오영희
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.1022-1028
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    • 1997
  • The reaction between Ni(Ⅱ) and sodium salt of 5,6-dihydro-1,4-dithiin-2,3-dithiolate (DDDT2-) in the presence of oxygen results in the formation of Ni(Ⅲ) species, Ni(DDDT)2-, which is isolated as tetraalkylammonium salt. The same reaction performed in the absence of oxygen yields dianionic Ni(Ⅱ) species, Ni(DDDT)22-, which is also isolated as the tetraethylammonium salt. The bis(5,6-dihydro-1,4-dithiin-2,3-dithiolato) nickelate (Ⅱ) dianion, Ni(DDDT)22-, reacts with methyl iodide to yield unusually stable bis(methylthio)dithiolene complex, Ni(CH3)2C8H8S8. All the isolated dithiolato-nickel(Ⅱ) and nickel(Ⅲ) complexes are characterized by 1H NMR, UV/Vis, IR and mass spectroscopic methods. The internal redox reaction of the nickel(Ⅱ)-dithiolate has been studied by spectro-electrochemical method and the results were compared with those of other metal-dithiolenes. The alkylated nickel(dithiolene) complex presumably undergoes cis-trans isomerization reaction in solution, judging from the experimental results of variable-temperature 1H NMR measurements.

Syntheses and Properties of New Nickel(II) Complexes of 14-Membered Pentaaza Macrocyclic Ligands with C-Nitro and N-Alkyl Pendant Arms

  • Kang, Shin-Geol;Choi, Jang-Sik
    • Bulletin of the Korean Chemical Society
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    • v.15 no.5
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    • pp.374-378
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    • 1994
  • Square planar nickel(II) complexes with various 1-alkyl derivatives of the 14-membered pentaaza macrocycle 8-methyl-8-nitro-1,3,6,10,13-pentaazacyclotetradecane can be readily prepared by two-step metal template condensation reactions of ethylenediamine, nitroethane, formaldehyde, and appropriate primary alkylamines. In coordinating solvents the nickel (II) complexes form octahedral species containing two axially coordinated solvent molecules and thus show square planar-octahedral equilibrium. The properties of the pentaaza macrocyclic complexes are considerably different from those of the complexes of analogous hexaaza and tetraaza macrocyclic complexes. Synthesis, characterization, and spectroscopic and chemical properties of the new complexes are described.

Synthesis, Crystal Structure and Spectroscopic Characterization of a Copper(II) Complex Coordinated by 2,2'-Dipyridylstearylamine

  • O, Yeong Hui;Kim, Ji Yeong;Park, Yeong Ja
    • Bulletin of the Korean Chemical Society
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    • v.22 no.4
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    • pp.379-382
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    • 2001
  • A new ligand containing the long aliphatic hydrocarbon chain, dipyridylstearylamine (dps) and its copper(Ⅱ) complex, Cu(dps)(NO3)2 have been prepared. The copper complex was characterized structurally and spectroscopically. The XRD crystal structure of the copper complex reveals that copper is octahedrally coordinated by dps and two nitrato ligands. The nitrato groups ligate asymmetrically to the copper. Crystal data are P1bar, a=8.249(2), b=10.416(3), $c=20.915(4)\AA$, $\alpha=86.54(2)$, $\beta=84.026(2)$, $\gamma=72.32(2)^{\circ}$, V=1702.7(7) $\AA3$ , Z=2, ${\lambda}$(Mo $K\alpha)=0.71073\AA$, $\mu=0.689$ mm-1 , T=293(2) K, R=0.0560 for 3529 reflections. The dps and the copper complex are stable in the air and the copper complex exhibits features of typical of other copper(Ⅱ) complexes containing dipyridylamine-based ligand.

A Newly Synthesized Schiff Base Derived from Condensation Reaction of 2,5-dichloroaniline and benzaldehyde: Its Applicability through Molecular Interaction on Mild Steel as an Acidic Corrosion Inhibitor by Using Electrochemical Techniques

  • Ozkir, Demet
    • Journal of Electrochemical Science and Technology
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    • v.10 no.1
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    • pp.37-54
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    • 2019
  • A new organic Schiff base compound N-benzylidene-2,5-dichloroaniline (BDC) was synthesized and the structure of the Schiff base is illuminated by some spectroscopic techniques. In addition, whether it is an applicable inhibitor in the industrial field was examined by conventional methods such as linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization for different concentrations. The BDC concentration and temperature effects were surveyed for elucidating the inhibitive mechanism. The BDC molecules are adsorbed to surface of mild steel via the Langmuir isotherm. Atomic force (AFM) and scanning electron microscope (SEM) techniques were utilized to give insight into surface characterization.

Phenolic glycosides from Pyrola japonica-(II)

  • Kim, Ju-Sun;Kang, Sam-Sik;Son, Kun-Ho;Chang, Hyeun-Wook;Kim, Hyun-Pyo;Bae, Ki-Hwan
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.202.3-202.3
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    • 2003
  • Two Known compounds, syringaresinol monoglucoside(8), chimaphilin(14), together with three new compounds, (9)[mp. $106{\sim} 111^{\circ}C$, C_{29}H_{44}O_{13}$], (10)[mp. $180{\sim}182^{\circ}C$, $C_{15}H_{20}O_{9}$] and (11)[mp. $100{\sim}105^{\circ}C$, $C_{18}H_{28}O_{8}$] were isolated from the BuOH fractionof Pyrola japonics(Pyrolaceae). The structures of the known compounds were determined by chemical and spectorscopic methods. The assignments of the $^{1}H-$ and $^{13}C-NMP$ spectra of these compounds were carried out by two-dimensional $^1H-^1H-COSY$, NOESY and $^1H-^{13}C$ multiple-bond, multiplequantum spectroscopic correlation techniques. The characterization of the three new compounds is now in progress.

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