© John Wiley & Sons Ltd
Volume 51, Issue 7
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
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.
Inguna Goba and Edvards Liepinsh
Version of Record online: 22 MAY 2013 | DOI: 10.1002/mrc.3959
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.
Josep Saurí and Teodor Parella
Version of Record online: 6 MAY 2013 | DOI: 10.1002/mrc.3960
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.
Jan Schraml, Peter Sandor, Stefan Korec, Martin Krump and Bronislav Foller
Version of Record online: 3 MAY 2013 | DOI: 10.1002/mrc.3961
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.
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
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.
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
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.
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
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.
Version of Record online: 29 APR 2013 | DOI: 10.1002/mrc.3955
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.
Kui-Wu Wang, Shi-Wei Wang and Qi-Zhen Du
Version of Record online: 30 APR 2013 | DOI: 10.1002/mrc.3956
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.
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
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.
Philippe Lesot, Zeinab Serhan, Christie Aroulanda and Isabelle Billault
Version of Record online: 14 JUN 2013 | DOI: 10.1002/mrc.3970
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