• Title/Summary/Keyword: Intermolecular interactions

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Experimental Determinations of Coherent Multidimensional Vibrational Spectroscopy

  • Besemann, Daniel;Condon, Nicholas;Meyer, Kent;Zhao, Wei;Wright, John C.
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1119-1125
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    • 2003
  • Coherent multidimensional vibrational spectroscopy is a new technique for establishing correlations between features in vibrational spectra that are caused by intra- and intermolecular interactions. These interactions cause cross-peaks between vibrational transitions that reflect the coupling. In this paper, we use Doubly Vibrationally Enhanced Infrared Spectroscopy (DOVE-IR) and DOVE-Raman processes to obtain coherent two dimensional vibrational spectra. The spectra are fitted to obtain the dephasing rates and third order susceptibilities $(χ^{(3)})$ for the nonlinear processes. We show that the DOVE $χ^{(3)}$ values are directly related to the molar absorptivities and Raman $χ^{(3)}$. We then use these relationships to obtain estimates for the $χ^{(3)}$ of the stimulated photon echo and $χ^{(5)}$ of the six wave mixing spectroscopies, respectively. We also predict the ratio of the cascaded four wave mixing signal to the six wave mixing signal.

Thermophysical Properties of Acetophenone with Ethylchloroacetate at Temperatures of 303.15, 313.15 and 323.15 K

  • Saravanakumar, K.;Baskaran, R.;Kubendran, T.R.
    • Journal of the Korean Chemical Society
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    • v.56 no.4
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    • pp.424-430
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    • 2012
  • Densities, viscosities, refractive indices and speed of sounds of the binary mixtures of Acetophenone with Ethylchloroacetate were measured over the entire mole fractions at (303.15, 313.15 and 323.15) K. From these experimental results, excess molar volume $V^E$, viscosity deviation ${\Delta}{\eta}$, refractive index deviation ${\Delta}n_D$, deviations in speed of sound ${\Delta}u$, deviations in isentropic compressibility ${\Delta}k_s$ and excess intermolecular free length ${\Delta}L_f$ were calculated. The viscosity data have been correlated with the equations of Grunberg and Nissan, Hind et al., Tamura and Kurata, Katti and Chaudri, Sedgwick, Krishnan-Laddha and McAllister. The thermo physical properties under study were fit to the Jouyban-Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

DSC and FTIR Studies of Miscible Poly(butylene 2,6-naphthalate)/Poly(4-vinylphenol) Blends (DSC와 FTIR을 이용한 상용성 (폴리부틸렌나프탈레이트/폴리비닐페놀) 블렌드의 연구)

  • 이준열;한지영
    • Polymer(Korea)
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    • v.26 no.6
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    • pp.737-744
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    • 2002
  • Thermodynamic miscibility of the binary blends composed of semi-crystalline poly (butylene 2,6-naphthalate) (PBN) and amorphous poly (4-vinylphenol) (PVPh) was investigated using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. DSC scan results showed that there was a single glass transition temperature (T$\_$g/) for each blend. Crystalline melting temperature (T$\_$m/) depression of the PBN in the blends was also observed with the increase of PVPh content. Both results of the single T$\_$g/ and the depression of T$\_$m/ for the PBN/PVPh blends indicate that the blends are thermodynamically miscible at the molecular level. FTIR spectroscopic analysis confirmed that strong intermolecular hydrogen bonding interactions between the ester carbonyl groups of the PBN and the hydroxyl groups of the PVPh are occurred.

Regioselective 1,3-Dipolar Cycloaddition and 1,2-Addition between Benzaldoxime NH-nitrone and Perfluoro-2-methyl-2-pentene

  • Lee, Chan-Woo;Park, Joo-Yuen;Kim, Hyun-Uk;Chi, Ki-Whan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1172-1176
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    • 2010
  • Regioselective perfluorinated [3+2] cycloadducts and 1,2-adducts have been prepared by 1,3-dipolar cycloaddition between benzaldoxime NH-nitrone and perfluorinated alkene, perfluoro-2-methyl-2-pentene. Although the cycloaddition reaction is carried out at room temperature, the corresponding perfluorinated compounds are effectively produced in a high yield. In particular, the methoxy-substituted adducts (4 and 7a) show the self-assembled structure by intermolecular interactions. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, and the absolute structure of perfluorinated adducts was confirmed by X-ray crystallography.

Crystal Structure of 3-Methyl-4-Methoxy-4'-Nitrostilbene

  • 서일환;김문집
    • Korean Journal of Crystallography
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    • v.3 no.2
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    • pp.67-71
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    • 1992
  • The crystal structure of the title compound was determined from single crystal X-ray dirt fraction study : C16H16NO3, Mr=271.316, orthorh ombic, Aba2, a=15.750(3), b=13.470(2), c=13.356 (2) A, V=2833A, Z=8, Dx=1.26 Mgm-3, λ(MoK a) =0.71069A, r=0.51mm-2, F(000)=1136, T=291 K, R=0.0414 for 728 unique observed [F≥3e(F)] reflections and 240 parameters. The molecule is nearly planar within 0.2 A with the torsion angle -179(2)°for C(4)-C(7)-C(8)-C(9).The into rmolecular interactions are mainly by van der Waals force with the nearest intermolecular distance 3.647A between O(3) and C(4) translated by half unit along band c-axes.

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Recent Advances in Electron Crystallography

  • Chung, Jeong Min;Lee, Sangmin;Jung, Hyun Suk
    • Applied Microscopy
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    • v.47 no.3
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    • pp.160-164
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    • 2017
  • Electron crystallography has been used as the one of powerful tool for studying the structure of biological macromolecules at high resolution which is sufficient to provide details of intramolecular and intermolecular interactions at near-atomic level. Previously it commonly uses two-dimensional crystals that are periodic arrangement of biological molecules, however recent studies reported a novel technical approach to electron crystallography of three-dimensional crystals, called micro electron-diffraction (MicroED) which involves placing the irregular and small sized protein crystals in a transmission electron microscope to determine the atomic structure. In here, we review the advances in electron crystallography techniques with several recent studies. Furthermore, we discuss the future direction of this structural approach.

From Gas Phase Clusters to Nanomaterials: An Overview of Theoretical Insights

  • Kim, Kwang-S.
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.757-762
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    • 2003
  • Since theoretical investigations of gas phase clusters enable the evaluation of intrinsic molecular properties and intermolecular interactions, one can predict the macroscopic properties of bulk matter, from a microscopic determination of the properties of individual atoms, molecules, or clusters. Based on the insights obtained from theoretical investigations of the properties of a large number of cluster systems (ranging from simple water clusters to large π-systems), we have investigated the properties of various novel molecular systems including endo/exohedral fullerenes, nanotori, nonlinear optical materials, ionophores/receptors, polypeptides, enzymes, organic nanotubes, nanowires, and electronic and nano-mechanical molecular devices. The present minireview highlights some of the interesting results obtained in the course of our extensive theoretical investigations of clusters and nanomaterials.

Interaction of FERM Domain of Tumor Suppressor, Merlin to its C-terminal Domain. (종양 억제 인자, Merlin의 FERM 도메인과 C-말단 도메인간의 결합)

  • Oh, Jeong-Il;Kang, Beom-Sik
    • Journal of Life Science
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    • v.17 no.9 s.89
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    • pp.1303-1307
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    • 2007
  • A tumor suppressor, merlin is a member of ERM family proteins. It consists of N-terminal FERM domain, ${\alpha}-helical$ region, and C-terminal domain. Alternative splicing of merlin's mRNA generates two isotypes of merlin. Isotype I, which has exon17 at the C-terminus instead of exon16 in isotype II, is known to have tumor suppressor activity. Like other ERM proteins, the C-terminal domain of merlin isotype I interacts to its FERM domain. That of isotype II, however, was reported not to bind FERM domain despite the large common part of C-terminal domain, which possibly binds FERM domain. Here, we show the binding of FERM domain to both C-terminal domains of merlin's two isotypes by isothermal titration calorimetry. These results support that merlin isotype II also can form a closed conformation or a multimer by intramolecular or intermolecular interactions using their FERM domain and C-terminal domain.

Synthesis and Their Physical Properties of Cationic Surfactants bearing Hydrophobic Chains of Aromatic Subtituents (방향족 치환기의 소수성 사슬을 갖는 양이온 계면활성제의 합성과 이의 물리화학적 특성 연구)

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.380-386
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    • 2013
  • N,N,N-Trimethyl-10-nitrophenoxy decylammonium bromide (N10TAB) and N,N,N,N-Tetramethyl-bis-[10-nitrophenoxy decyl]-1,6-hexanediammonium dibromide (N10-6-10N), bearing aromatic nitrophenoxy group in the end of their hydrophobic chains have been prepared, and their properties in aqueous solutions have been studied by conductivity and H-NMR spectroscopy. Below the critical micelle concentration N10-6-10N form premicelle with two or three surfactant molecules. Beyond the critical micelle concentration two molecules have strong self-aggregation ability and form micelles of rather small size and with small aggregation numbers. H-NMR at different concentrations give the informations on the environmental changes of the surfactants on their micellization progress.

Complex Ordering of Supramolecular Dendrimers in Confined Geometries.

  • Yoon, Dong-Ki;Choi, Myung-Chul;Kim, Yun-Ho;Kim, Mahn-Won;Jung, Hee-Tae
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.189-189
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    • 2006
  • The self-assembly of supramolecular dendrimers allows the rapid construction of nanosized structures with regularly ordered features that depend on the shape of the molecules and the relative strength of the intra-and intermolecular interactions. Here we report on a dramatic improvement in the degree of control and selectivity in the orientation of fan-shaped supramolecular molecules over a large area, which has been achieved by confined geometries and applied fields. The order and orientation of supramolecular dendrimers can be controlled by surface anchoring in confined geometries. POM, SEM, TEM, AFM and XRD results show that the molecules form the complicated defect-ordering in the microchannels with different feature sizes. We show that these defect domains are strongly influenced by the boundary and feature size of the surfaces. This technique can be used to create a grain size in the plane of the film that is much larger than that which can be achieved using previously reported soft-material based pattering.

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