Magnetic Resonance in Chemistry

Cover image for Vol. 53 Issue 1

Early View (Online Version of Record published before inclusion in an issue)

Edited By: Dr James Keeler

Impact Factor: 1.559

ISI Journal Citation Reports © Ranking: 2013: 23/44 (Spectroscopy); 68/148 (Chemistry Multidisciplinary); 90/136 (Chemistry Physical)

Online ISSN: 1097-458X

VIEW

  1. 1 - 37
  1. Letter - spectral assignments

    1. A new alkaloid from Helianthemum ordosicum

      Qinghu Wang, Rongjun Wu, Jiesi Wu, Nayintai Dai and Narenchaoketu Han

      Article first published online: 12 DEC 2014 | DOI: 10.1002/mrc.4194

  2. Research articles

    1. Electron spin relaxation times and rapid scan EPR imaging of pH-sensitive amino-substituted trityl radicals

      Hanan B. Elajaili, Joshua R. Biller, Mark Tseitlin, Ilirian Dhimitruka, Valery V. Khramtsov, Sandra S. Eaton and Gareth R. Eaton

      Article first published online: 12 DEC 2014 | DOI: 10.1002/mrc.4193

      Thumbnail image of graphical abstract

      For amino-substituted triarylmethyl radicals, T1 is independent of pH, but dynamic processes make T2 pH dependent. The feasibility of rapid-scan electron paramagnetic resonance imaging of the pH dependence was demonstrated at 250 MHz.

    2. EPR study of the relationship between ultra high molecular weight polyethylene structure and radicals formed during irradiation with high energy sources

      Valentina Brunella and Maria Cristina Paganini

      Article first published online: 5 NOV 2014 | DOI: 10.1002/mrc.4175

      Thumbnail image of graphical abstract

      Three different samples of ultra high molecular weight polyethylene have been irradiated with high energy source (electron beam), and radicals have been generated. Electron paramagnetic resonance data have been used to evaluate the amount of each kind of radicals that have been generated on different starting materials.

    3. New synthesis on the basis 2-allyloxy chalcone and NMR studies its some derivatives

      I. G. Mamedov, M. R. Bayramov, Y. V. Mamedova and A. M. Maharramov

      Article first published online: 5 NOV 2014 | DOI: 10.1002/mrc.4172

      Thumbnail image of graphical abstract

      The conformational and keto-enol tautomerism in the investigated compounds have been confirmed by NMR and chemical methods.

  3. Special issue research articles

    1. Effects of ions on water structure: a low-field 1H T1 NMR relaxometry approach

      Pellegrino Conte

      Article first published online: 30 OCT 2014 | DOI: 10.1002/mrc.4174

      Thumbnail image of graphical abstract

      Salts were dissolved in water at different concentrations and analyzed by 1H T1 NMR relaxometry with a fast field cycling setup at a fixed magnetic field. Results confirmed literature data concerning kosmotropic and chaotropic nature of ions. However, new mathematical model was suggested to account for the inter-ion interactions at high salt concentration.

  4. Research articles

    1. HOBS methods for enhancing resolution and sensitivity in small DNA oligonucleotide NMR studies

      Josiah M. McKenna and John A. Parkinson

      Article first published online: 29 OCT 2014 | DOI: 10.1002/mrc.4182

      Thumbnail image of graphical abstract

      Band-selective homonuclear broadband decoupling of DNA 1H NMR spectra can effectively improve signal resolution without loss of intensity or an increase in magnetic field strength, opening up the study of more complex DNA samples in solution by 1H NMR.

    2. DFT 1H–1H coupling constants in the conformational analysis and stereoisomeric differentiation of 6-heptenyl-2H-pyran-2-ones: configurational reassignment of synargentolide A

      Francisco Juárez-González, Gloria Alejandra Suárez-Ortiz, Mabel Fragoso-Serrano, Carlos M. Cerda-García-Rojas and Rogelio Pereda-Miranda

      Article first published online: 29 OCT 2014 | DOI: 10.1002/mrc.4178

      Thumbnail image of graphical abstract

      DFT 1H–1H NMR coupling constant calculations, including solvation parameters with the polarizable continuum model, together with the experimental values measured by spectral simulation, were used to predict the stereochemistry of flexible and highly polyoxygenated 6-heptenyl-5,6-dihydro-2H-pyran-2-ones with multiple chiral centers allowing epimer differentiation. Using this DFT NMR integrated approach, the configurational reassignment of synargentolide A was accomplished.

    3. High-resolution slice selection NMR for the measurement of CO2 diffusion under non-equilibrium conditions

      Jesse Allen and Krishnan Damodaran

      Article first published online: 29 OCT 2014 | DOI: 10.1002/mrc.4176

      Thumbnail image of graphical abstract

      We present a simple and an efficient approach using spatially selective NMR to investigate solvation and diffusion of CO2 in ionic liquids. The techniques demonstrated here are shown as novel and effective means of studying solvated gas dynamics under non-equilibrium conditions without the need for conventional high power gradients.

  5. Special issue research articles

    1. Non-targeted analyses of organic compounds in urban wastewater

      Elenilson G. Alves Filho, Luci Sartori, Lorena M. A. Silva, Bianca F. Silva, Pedro S. Fadini, Ronald Soong, Andre Simpson and Antonio G. Ferreira

      Article first published online: 29 OCT 2014 | DOI: 10.1002/mrc.4169

      Thumbnail image of graphical abstract

      Two methods to study wastewater samples are employed: non-targeted NMR spectroscopic analysis to characterize the largest possible number of compounds from urban wastewater and analysis by HPLC-(UV/MS)-SPE-ASS-NMR to detect non-specific recalcitrant organic compounds without the use of common standards. The results indicated that the procedure can be useful in the identification of the pollution source and to enhance the effectiveness of WWTPs in designing preventive action to protect the equipment and preserve the environment.

  6. Letter - spectral assigments

    1. A QSPR correlation on the 13C NMR chemical shifts of bridge carbons for different series of aromatic Schiff bases

      Guanfan Chen, Xiangsi Wu, Chenzhong Cao, Fengping Liu, Rongjin Zeng and Wanqiang Liu

      Article first published online: 23 OCT 2014 | DOI: 10.1002/mrc.4148

  7. Letter - correspondence

  8. Research articles

    1. Chiral discrimination of secondary alcohols and carboxylic acids by NMR spectroscopy

      Indrani Pal, Sachin R. Chaudhari and Nagaraja Rao Suryaprakash

      Article first published online: 21 OCT 2014 | DOI: 10.1002/mrc.4167

      Thumbnail image of graphical abstract

      The strategy adopted in this article for enantiodiscrimination of secondary alcohols and carboxylic acids by using a three-component mixture chiral solvating agent by NMR spectroscopy is simple, cost effective, and efficient. In the presence of 4-dimethylaminopyridine (DMAP), the enantiopure mandelic acid is able to discriminate racemic secondary alcohols, and another way, in the presence of DMAP, enantiopure 1-phenyl ethanol can discriminate racemic carboxylic acid as well. The designed protocol also allows accurate measurement of enantiomeric excess.

    2. Characterization and quantification of microstructures of a fluorinated terpolymer by both homonuclear and heteronuclear two-dimensional NMR spectroscopy

      Salim Ok

      Article first published online: 17 OCT 2014 | DOI: 10.1002/mrc.4156

      Thumbnail image of graphical abstract

      Microstructures of terpolymer of tetrafluorethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (VDF), named THV are analyzed by gCOSY and gHSQC NMR measurements. Nearly 50% of the TFE units are neighbor, whereas more than 90% of the HFP units are closer to VDF units. The chemical environments of the monomers are clarified. VDF unit was polymerized by either (−CF2−CH2−) or (−CH2−CF2−) propagation. THV is a random polymer with a limited fraction of TFE-TFE and TFE-HFP sequence orders.

  9. Letter - spectral assignments

    1. Two new sesquiterpenoids from Artemisia annua

      Hai-bo Li, Yang Yu, Zhen-zhong Wang, Jun Yang, Wei Xiao and Xin-sheng Yao

      Article first published online: 16 OCT 2014 | DOI: 10.1002/mrc.4168

    2. Polysulfonylated cyclodextrins. Part 14. Structural validation of tris-and pentakis(6-O-mesitylsulfony)cyclomaltooctaose isomers by 1H-NMR spectrometry

      Hatsuo Yamamura, Mutsumi Watanabe, Sho Kawahara, Atsushi Miyagawa and Masao Kawai

      Article first published online: 16 OCT 2014 | DOI: 10.1002/mrc.4165

      Thumbnail image of graphical abstract

      Regioisomers of tri- and penta-6-O-mesitylenesulfonates of cyclomaltoctaose (γ-cyclodextrin) were discriminated and assigned by high-resolution 1H NMR techniques.

  10. Special issue research articles

    1. Characterization of wet aggregate stability of soils by 1H-NMR relaxometry

      C. Buchmann, M. Meyer and G. E. Schaumann

      Article first published online: 10 OCT 2014 | DOI: 10.1002/mrc.4147

      Thumbnail image of graphical abstract

      1H nuclear magnetic resonance relaxometry is introduced as a tool to assess the stability of soil aggregates against hydraulic stress and occurring mechanisms at the same time. The application of 1H nuclear magnetic resonance relaxometry revealed the possibility to quantify the percentage of water-stable aggregates and additional effects of clay swelling on the water percolation through packed soil aggregate columns.

  11. Research articles

    1. Nuclear magnetic resonance using electronic referencing: method validation and evaluation of the measurement uncertainties for the quantification of benzoic acid in orange juice

      Bruno C. Garrido and Lucas J. de Carvalho

      Article first published online: 10 OCT 2014 | DOI: 10.1002/mrc.4166

      Thumbnail image of graphical abstract

      Electronic referencing in NMR for orange juice analysis has been evaluated. Method was validated, and its measurement uncertainty was estimated. Method performance was extremely good, and uncertainties are discussed.

  12. Letter - spectral assignments

    1. 1H and 13C NMR assignments of three new tricycloalternarenes from endophytic fungus Alternaria tenuissima HS03-07

      Haifeng Wang, Jiao Bai, Gang Chen, Zi-qi Liu, Xuan Lu and Yue-Hu Pei

      Article first published online: 8 OCT 2014 | DOI: 10.1002/mrc.4159

  13. Special issue letter - case reports

    1. In vivo NMR spectroscopy: toward real time monitoring of environmental stress

      Ronald Soong, Edward Nagato, Andre Sutrisno, Blythe Fortier-McGill, Mohammad Akhter, Sebastian Schmidt, Hermann Heumann and André J. Simpson

      Article first published online: 8 OCT 2014 | DOI: 10.1002/mrc.4154

  14. Special issue mini-reviews

    1. NMR spectroscopy to follow reaction progress in ionic liquids

      Bradley J. Butler, Donald S. Thomas, James M. Hook and Jason B. Harper

      Article first published online: 7 OCT 2014 | DOI: 10.1002/mrc.4161

      Thumbnail image of graphical abstract

      This review highlights the advantages of NMR spectroscopy over other analytical techniques in following reaction progress in ionic liquids, particularly addressing the practical aspects of the methodology and highlighting the range of processes that can be readily followed.

  15. Letter - spectral assignments

    1. 1H and 13C NMR assignments of tricanguinas A–B, coumarin monoterpenes from Trichosanthes anguina L

      Nguyen Xuan Nhiem, Hoang Thi Yen, Phan Van Kiem, Chau Van Minh, Bui Huu Tai, Hoang Le Tuan Anh, SeonJu Park, Nanyoung Kim and Seung Hyun Kim

      Article first published online: 6 OCT 2014 | DOI: 10.1002/mrc.4150

  16. Special issue reviews

    1. Advancements in waste water characterization through NMR spectroscopy: review

      Elenilson G. Alves Filho, Lorena M. Alexandre e Silva and Antonio G. Ferreira

      Article first published online: 3 OCT 2014 | DOI: 10.1002/mrc.4158

      Thumbnail image of graphical abstract

      NMR has proven to be a valuable analytical tool in characterizing of compounds in a wide range of mixtures and providing physical information (rigidity and dynamics). Hyphenation with other techniques creates unprecedented capabilities for the identification of novel and unknown chemical species. This article summarizes the NMR methods applied in studies of organic pollutants from wastewater to provide an exhaustive review of the literature and a guide for readers interested in this topic.

  17. Research articles

    1. Suppression of phase and amplitude J(HH) modulations in HSQC experiments

      Laura Castañar, Eduard Sistaré, Albert Virgili, R. Thomas Williamson and Teodor Parella

      Article first published online: 3 OCT 2014 | DOI: 10.1002/mrc.4149

      Thumbnail image of graphical abstract

      The amplitude and the phase of cross-peaks in conventional 2D HSQC experiments are modulated by both proton–proton, J(HH), and proton–carbon, 1J(CH), coupling constants. It is shown by spectral simulation and experimentally that J(HH) interferences are suppressed in a novel perfect-HSQC pulse scheme that incorporates perfect-echo INEPT periods. The improved spectra afford pure in-phase cross-peaks with respect to 1J(CH) and J(HH), irrespective of the experiment delay optimization, providing better analysis in terms of J measurement or signal integration.

  18. Letter - spectral assignments

    1. Proton NMR investigations on 6-alkylamino-2-alkylthioadenosine derivatives

      Hongguang Du, Qiwen He, Ning Chen, Jiaxi Xu, Fei Chen and Guocheng Liu

      Article first published online: 3 OCT 2014 | DOI: 10.1002/mrc.4151

    2. Structure determination of two unusual C25 steroids with bicyclo[4.4.1]A/B rings from Penicillium decumbens by NMR spectroscopy

      Sheng Lin, Ke-Yv Chen, Peng Fu, Ji Ye, Yong-Qing Su, Xian-Wen Yang, Zhong-Xiao Zhang, Lei Shan, Hui-Liang Li, Yun-Heng Shen, Run-Hui Liu, Xi-Ke Xu and Wei-Dong Zhang

      Article first published online: 30 SEP 2014 | DOI: 10.1002/mrc.4155

  19. Research articles

    1. Investigation of the resonance-assisted hydrogen bond in model β-diketones through localized molecular orbital analysis of the spin–spin coupling constants related to the O–H · · · O hydrogen bond

      M. Natalia C. Zarycz and Patricio F. Provasi

      Article first published online: 30 SEP 2014 | DOI: 10.1002/mrc.4152

      Thumbnail image of graphical abstract

      The resonance-assisted hydrogen bond phenomenon has been studied theoretically by a localized molecular orbital (LMO) decomposition of the spin–spin coupling constants between atoms either involved or close to the O–H · · · O system of some β-diketones and their saturated counterparts. The contributions in terms of LMO to the paramagnetic spin orbital and the spin dipolar Ramsey terms prove the importance of the delocalized π-electron structure supporting the idea of the existence of the resonance-assisted hydrogen bond phenomenon.

    2. Structure of pravastatin and its complex with sodium dodecyl sulfate micelles studied by NMR spectroscopy

      L. F. Galiullina, I. Z. Rakhmatullin, E. A. Klochkova, A. V. Aganov and V. V. Klochkov

      Article first published online: 26 SEP 2014 | DOI: 10.1002/mrc.4146

      Thumbnail image of graphical abstract

      The aim of this work was to study the mechanisms of interaction between pravastatin and cell membranes using model membranes (sodium dodecyl sulfate micelles) by NMR spectroscopy methods. The results of 2D NOESY NMR experiments showed that pravastatin can form intermolecular complex with SDS micelles by the interaction of its hydrophilic groups with polar surface of the micelle. Conformational features of pravastatin molecule were also studied.

    3. ESR and calculations on electronic structure of phenalenyl and phenalenyl derivative radicals

      Marilene Turini Piccinato, Marcello Ferreira da Costa, André Tsutomu Ota, Carmen Luísa Barbosa Guedes and Eduardo Di Mauro

      Article first published online: 26 SEP 2014 | DOI: 10.1002/mrc.4140

      Thumbnail image of graphical abstract

      Calculations on electronic structure of the perinaphthenyl radical and phenalenyl derivative radicals were performed to obtain support for the experimental ESR results. The energy-minimized structures were obtained using the density functional theory method. The differences between experimental and theoretical values were below 7% in the first-order (A) and 20% in the second-order (A′) hyperfine coupling constants, for all structures analyzed.

  20. Letter - spectral assignments

    1. The 1H, 13C, 15N, and 19F NMR chemical shifts assignments in 5,10,15-tris (pentafluorophenyl)tetra–15N corrole at 191 K

      Wojciech Bocian, Piotr Paluch, Agnieszka Nowak-Król, Daniel T. Gryko, Marek Potrzebowski, Justyna Śniechowska, Jerzy Sitkowski, Elżbieta Bednarek and Lech Kozerski

      Article first published online: 19 SEP 2014 | DOI: 10.1002/mrc.4145

  21. Research articles

    1. 3He NMR studies on helium–pyrrole, helium–indole, and helium–carbazole systems: a new tool for following chemistry of heterocyclic compounds

      Klaudia Radula-Janik and Teobald Kupka

      Article first published online: 16 SEP 2014 | DOI: 10.1002/mrc.4141

      Thumbnail image of graphical abstract

      The 3He nuclear magnetic shieldings were calculated for free helium atom and He–pyrrole, He–indole, and He–carbazole complexes. Our results, obtained with BHandHLYP method, predicted fairly accurately the He–pyrrole plane separation of 3.15 Å (close to 3.24 Å, calculated by MP2) and yielded a sizable 3He NMR chemical shift (about −1.5 ppm).

    2. Dynamic nuclear polarization enhancement of protons and vanadium-51 in the presence of pH-dependent vanadyl radicals

      Angel J. Perez Linde, Diego Carnevale, Pascal Miéville, Andrzej Sienkiewicz and Geoffrey Bodenhausen

      Article first published online: 16 SEP 2014 | DOI: 10.1002/mrc.4138

      Thumbnail image of graphical abstract

      The electron paramagnetic resonance response of samples containing vanadyl sulfate may be silenced by regulating the pH, so that paramagnetic agents like TOTAPOL can dominate the hyperpolarization of protons and cross-polarization from protons to nuclear 51V spins is possible.

  22. Special issue perspectives

    1. Perspective: in vivo NMR – a potentially powerful tool for environmental research

      André J. Simpson, Yalda Liaghati, Blythe Fortier-McGill, Ronald Soong and Mohammad Akhter

      Article first published online: 16 SEP 2014 | DOI: 10.1002/mrc.4142

  23. Letter - spectral assignments

    1. Structural confirmation of a new hydroxylated tung oil compound by NMR

      Wei Zhao, Huafen Wang, Zhiyong Ren, Lei Jiang, Yang Fu and Xiuli Wang

      Article first published online: 5 SEP 2014 | DOI: 10.1002/mrc.4133

  24. Research articles

    1. Reduced dimensionality (3,2)D NMR experiments and their automated analysis: implications to high-throughput structural studies on proteins

      Jithender G. Reddy, Dinesh Kumar and Ramakrishna V. Hosur

      Article first published online: 1 SEP 2014 | DOI: 10.1002/mrc.4135

      Thumbnail image of graphical abstract

      Two reduced dimensionality-based (3,2)D NMR experiments are presented to improve the backbone assignment process both in terms of its accuracy and speed. The linear combination of backbone 15N and sequential 13CO/13Cα chemical shifts provides better dispersions in spectra. The distinctive peak patterns of self and sequential peaks in four (3,2)D spectra enable unambiguous sequence specific assignment. The spectral features allow ready automation of the backbone resonance assignment using AUTOBA algorithm. Implication to high-throughput structural studies on proteins has been demonstrated.

    2. Stereochemical behavior of geminal and vicinal 77Se–13C spin–spin coupling constants studied at the SOPPA(CC2) level taking into account relativistic corrections

      Yury Yu. Rusakov and Leonid B. Krivdin

      Article first published online: 1 SEP 2014 | DOI: 10.1002/mrc.4139

      Thumbnail image of graphical abstract

      A systematic theoretical study of geminal and vicinal 77Se–13C spin–spin coupling constants in the series of the open-chain selenides and selenium-containing heterocycles revealed that relativistic effects play an essential role in the selenium–carbon coupling constants, especially when the coupling pathway includes a triple bond, contributing to about 10–15% of their total values and noticeably improving the agreement of the calculated couplings with experiment. Both geminal and vicinal 77Se–13C spin–spin coupling constants show marked stereochemical behavior as documented by their calculated dihedral angle dependences that could be used as a practical guide in stereochemical studies of organoselenium compounds.

  25. Letter - spectral assignment

    1. A new secoiridoid glycosidic lignan ester from the leaves of Olea ferruginea

      Muhammad Ali Hashmi, Afsar Khan, Umar Farooq, Mubeen Rani, Viqar Uddin Ahmad and Abdur Rahman Khan

      Article first published online: 28 AUG 2014 | DOI: 10.1002/mrc.4134

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