Magnetic Resonance in Chemistry

Cover image for Vol. 51 Issue 7

July 2013

Volume 51, Issue 7

Pages 383–445

  1. Research Articles

    1. Top of page
    2. Research Articles
    3. MRC Letters
    4. Erratum
    1. Coniothyrione: anatomy of a structure revision (pages 383–390)

      Gary E. Martin, Alexei V. Buevich, Mikhail Reibarkh, Sheo B. Singh, John G. Ondeyka and R. Thomas Williamson

      Version of Record online: 15 MAY 2013 | DOI: 10.1002/mrc.3952

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      Advanced microscale 2D NMR techniques have been utilized to unequivocally confirm the recent suggested revision of the structure of coniothyrione on the basis of chemical shift calculations and a biogenetic argument. The structure has been rigorously confirmed as the 4-chloro xanthone using 1,1-ADEQUATE and high level density functional theory calculations of 13C chemical shifts as well as nJCH and nJCC (n = 1–3) coupling constants. There is excellent agreement between the calculated and measured parameters for the 4-chloro xanthone.

    2. 15N NMR of 1,4-dihydropyridine derivatives (pages 391–396)

      Inguna Goba and Edvards Liepinsh

      Version of Record online: 22 MAY 2013 | DOI: 10.1002/mrc.3959

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      The NMR chemical shifts and coupling constants of various symmetrically and unsymmetrically substituted 1,4-dihydropyridine derivatives are discussed in terms of their relationship to structural features such as character and position of the substituent in heterocycle, N-alkyl substitution, nitrogen lone pair delocalization within the conjugated system, and steric effects.

    3. Simultaneous measurement of J(HH) and two different nJ(CH) coupling constants from a single multiply edited 2D cross-peak (pages 397–402)

      Josep Saurí and Teodor Parella

      Version of Record online: 6 MAY 2013 | DOI: 10.1002/mrc.3960

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      Three different J-editing methods (IPAP, E.COSY and J-resolved) are implemented in a single NMR experiment to provide spin-state-edited 2D cross-peaks from which a simultaneous measurement of different homonuclear and heteronuclear coupling constants can be performed. A new J-selHSQMBC-IPAP experiment is proposed for the independent measurement of two different nJ(CH) coupling constants along the F2 and F1 dimensions of the same 2D cross-peak. In addition, the E.COSY pattern provides additional information about the magnitude and relative sign between J(HH) and nJ(CH) coupling constants.

    4. Improved baseline in 29Si NMR spectra of water glasses (pages 403–406)

      Jan Schraml, Peter Sandor, Stefan Korec, Martin Krump and Bronislav Foller

      Version of Record online: 3 MAY 2013 | DOI: 10.1002/mrc.3961

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      Replacing one-pulse sequence by RIDE (ring down elimination) pulse sequence dramatically improves the baseline of 29Si NMR spectra and eliminates the signal from the probe.

    5. Characterization by NMR of reactants and products of hydrofluoroether isomers, CF3(CF2)3OCH3 and (CF3)2C(F)CF2OCH3, reacting with isopropyl alcohol (pages 407–413)

      Howard C. Knachel, Vladimir Benin, William E. Moddeman, Janine C. Birkbeck, Thomas A. Kestner and Tanya L. Young

      Version of Record online: 23 MAY 2013 | DOI: 10.1002/mrc.3964

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      The titled hydrofluoroether isomers react slowly with isopropyl alcohol in a two-step process yielding isopropylmethyl ether, the corresponding isopropyl ester isomers, and HF. 19F and 1H NMR chemical shifts, multiplicities, and coupling constants are assigned to the reactants and major products in this paper.

    6. Experimental and theoretical study of the intramolecular C–H···N and C–H···S hydrogen bonding effects in the 1H and 13C NMR spectra of the 2-(alkylsulfanyl)-5-amino-1-vinylpyrroles: a particular state of amine nitrogen (pages 414–423)

      Andrei V. Afonin, Dmitry V. Pavlov, Alexander I. Albanov, Ol'ga A. Tarasova and Nina A. Nedolya

      Version of Record online: 22 MAY 2013 | DOI: 10.1002/mrc.3967

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      There is an extraordinarily large chemical shift of HB proton in the 2-(alkylsulfanyl)-5-amino-1-vinylpyrroles. The 1J(Cβ,HB) coupling constant is surprisingly greater than the 1J(Cβ,HA) coupling constant. According to MP2 calculations, the amine nitrogen lone pair is removed from the conjugation with the π-system of the pyrrole ring and directed toward the HB hydrogen in the s-cis(N) conformation. The sulfur and HB hydrogen are spatially close in the s-cis(S) conformation. Quantum theory of atoms in molecules (QTAIM) analysis suggests the formation of the weak intramolecular C–H•••N and C–H•••S hydrogen bonds, which cause discovered spectral anomalies.

    7. Micelle structure and molecular self-diffusion in isononylphenol ethoxylate–water systems (pages 424–430)

      Victor P. Arkhipov, Elisaveta F. Potapova, Oleg N. Antzutkin and Andrei V. Filippov

      Version of Record online: 23 MAY 2013 | DOI: 10.1002/mrc.3968

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      Sizes of micelles of surfactants C9H19C6H4O(C2H4O)nH (where n = 6,8,9,10 and 12) were determined for different surfactant aqueous concentrations by NMR-diffusometry, dynamic light scattering and viscosimetry. Numbers of water molecules bound by a micelle and by one oxyethylene group of the surfactant were estimated.

  2. MRC Letters

    1. Top of page
    2. Research Articles
    3. MRC Letters
    4. Erratum
    1. One-step synthesis of 6-acetamido-3-(N-(2-(dimethylamino) ethyl) sulfamoyl) naphthalene-1-yl 7-acetamido-4-hydroxynaphthalene-2-sulfonate and its characterization with 1D and 2D NMR techniques (pages 431–434)

      Wei Zhang

      Version of Record online: 29 APR 2013 | DOI: 10.1002/mrc.3955

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      6-Acetamido-3-(N-(2-(dimethylamino) ethyl) sulfamoyl) naphthalene-1-yl 7-acetamido-4-hydroxynaphthalene-2-sulfonate was prepared by a one-step method. The structure of the compound was elucidated by 1D and 2D NMR. The chemical shift differences of 1H and 13C being δ 0.04 and 0.2, respectively, were unambiguously differentiated.

    2. Complete NMR assignment of retinal and its related compounds (pages 435–438)

      Kui-Wu Wang, Shi-Wei Wang and Qi-Zhen Du

      Version of Record online: 30 APR 2013 | DOI: 10.1002/mrc.3956

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      Complete and unambiguous 1H and 13C NMR chemical shift assignments for all-trans-retinal, 13-cis-retinal, 11-cis-retinal and 9-cis-retinal (1–4) have been established by means of 1-D and 2-D NMR spectroscopic experiments.

    3. Structural studies of the chemical constituents of Tithonia tagetiflora Desv. (Asteraceae) (pages 439–443)

      Ngoc Vinh Huynh, Thi Hoai Thu Nguyen, Kim Phi Phung Nguyen and Poul Erik Hansen

      Version of Record online: 16 MAY 2013 | DOI: 10.1002/mrc.3963

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      The structure of two new sesquiterpene lactones, 8-angeloyloxy-2,14-epoxygermacra-4,10(1),11(13)-trien-6,12-olide (1) and 6-angeloyloxy-1-hydroxy-3,4-epoxygermacra-9,11(13)-dien-8,12-olide (2), are elucidated by using NMR spectra.

  3. Erratum

    1. Top of page
    2. Research Articles
    3. MRC Letters
    4. Erratum
    1. You have free access to this content
      Analytical contribution of NAD 2D-NMR spectroscopy in polypeptide mesophases to the investigation of triglycerides (pages 444–445)

      Philippe Lesot, Zeinab Serhan, Christie Aroulanda and Isabelle Billault

      Version of Record online: 14 JUN 2013 | DOI: 10.1002/mrc.3970

      This article corrects:

      Analytical contribution of NAD 2D-NMR spectroscopy in polypeptide mesophases to the investigation of triglycerides

      Vol. 50, Issue Supplement S1, S2–S11, Version of Record online: 21 DEC 2012