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Data for Measuring multiple 17O-13C J-couplings in naphthalaldehydic acid : a combined solid state NMR and density functional theory approach
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Rees, Gregory J., Day, Stephen Paul, Barnsley, Kristian E., Iuga, Dinu, Yates, Jonathan R., Wallis, John D. and Hanna, John V. (2020) Data for Measuring multiple 17O-13C J-couplings in naphthalaldehydic acid : a combined solid state NMR and density functional theory approach. [Dataset]
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C9CP03977E_NAP_Raw_Data.zip - Published Version Available under License Creative Commons Attribution 4.0. Download (16Mb) |
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Plain Text (README file)
README.txt - Published Version Available under License Creative Commons Attribution 4.0. Download (524b) |
Abstract
A combined multinuclear solid state NMR and gauge included projected augmented wave, density functional theory (GIPAW DFT) computational approach is evaluated to determine the four heteronuclear 1J(13C,17O) couplings in solid 17O enriched naphthalaldehydic acid. Direct multi-field 17O magic angle spinning (MAS), triple quantum MAS (3QMAS) and double rotation (DOR) experiments are initially utilised to evaluate the accuracy of the DFT approximations used in the calculation of the isotropic chemical shifts (δiso), quadrupole coupling constants (CQ) and asymmetry (ηQ) parameters. These combined approaches give δiso values of 313, 200 and 66 ppm for the carbonyl (C=O), ether (–O–) and hydroxyl (–OH) environments, respectively, with the corresponding measured quadrupole products (PQ) being 8.2, 9.0 and 10.6 MHz. The geometry optimised DFT structure derived using the CASTEP code gives firm agreement with the shifts observed for the ether (δiso = 223, PQ = 9.4 MHz) and hydroxyl (δiso = 62, PQ = 10.5 MHz) environments but the unoptimised experimental XRD structure has better agreement for the carbonyl group (δiso = 320, PQ = 8.3 MHz). The determined δiso and ηQ values are shown to be consistent with bond lengths closer to 1.222 Å (experimetnal length) rather than the geometry optimised length of 1.238 Å. The geometry optimised DFT 1J(13C,17O) coupling to the hydroxyl is calculated as 20 Hz and the couplings to the ether were calculated to be 37 (O–C=O) and 32 (O–C–OH) Hz. The scalar coupling parameters for the unoptimised experimental carbonyl group predict a 1J(13C,17O) value of 28 Hz, whilst optimisation gives a value of 27 Hz. These calculated 1J(13C,17O) couplings, together with estimations of the probability of each O environment being isotopically labelled (determined by electrospray ionisation mass spectrometry) and the measured refocussable transverse dephasing (T2’) behaviour, are combined to simulate the experimental decay behaviour. Good agreement between the measured and calculated decay behaviour is observed.
Item Type: | Dataset | ||||||
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Subjects: | Q Science > QC Physics | ||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | ||||||
Type of Data: | Experimental data | ||||||
Library of Congress Subject Headings (LCSH): | Density functionals, Aldehydes, Nuclear magnetic resonance spectroscopy | ||||||
Publisher: | University of Warwick, Department of Physics | ||||||
Official Date: | 9 January 2020 | ||||||
Dates: |
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Status: | Not Peer Reviewed | ||||||
Publication Status: | Published | ||||||
Media of Output (format): | .txt .magres .pdf | ||||||
Copyright Holders: | University of Warwick | ||||||
Description: | The following datasets are present in the folder: mass_spectrometery = contains all the mass spec data supplied from the national service in Swansea. OxygenDOR = text files of the DOR data at various magnetic fields OxygenNMR_MQMAS = text files for the 1D 17O NMR at various fields and Bruker binary files for the MQMAS at 700 MHz Proton_Carbon_DeuteriumNMR = 1H,13C, 2H text files and HETCOR Bruker binary files. DFT_CASTEP = The CASTEP magres files. J_Coupling = The heteronuclaer spin echo decay data Note that Bruker TOPSPIN software is required to open some of the files. |
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Date of first compliant deposit: | 9 January 2020 | ||||||
Date of first compliant Open Access: | 9 January 2020 | ||||||
Contributors: |
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