1H–17O Nuclear-Quadrupole Double-Resonance Study of Hydrogen Disorder in 2-Nitrobenzoic Acid

Torkar, M; Žagar, V.; Seliger, J.

doi:10.1006/jmre.2000.2051

Cited by 16 publications

(17 citation statements)

References 13 publications

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“…It has been found that practically in all cases of carboxylic oxygen (i. e. 17 O nuclei, I = 5/2) in various H-bonded systems the values of χ eff are between 7.5 and 9.2 MHz [12]. They also match rather well with the corresponding data of benzoic acid in solutions [15,16], solid carboxylic acids [19,20], as well as with the results of theoretical calculations [21,22]. All these 'well matching' χ eff values have been obtained from (2) using experimentally measured ∆ν 1/2 (Fig.…”

Section: Resultssupporting

confidence: 69%

CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

Balevičius¹,

Fueß²

2005

Lith. J. Phys.

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The hydrogen bond (H-bond) in the complex of cyanopyridine (4-pyridincarbonitrile, C6H4N2, further CyPy) with trichloroacetic acid (TCA) was investigated in the solid state and in the solution (1 M in CH3CN). The 13 C CP / MAS results as well as X-ray and neutron diffraction reveal a complete proton transfer (CPT) for the CyPy•TCA complex. An experimental criterion of the threshold of CPT is proposed. Reorientational dynamics of 'free' and 'bonded' CyPy molecules in solution were investigated by 17 O and 13 C NMR relaxation time and nuclear Overhauser effect (NOE) factor measurements. The rotational diffusion even of 'free' CyPy molecules is anisotropic, with a corresponding correlation time of 3 ps for rotation and that of 6 ps for tumbling at 293 K. The formation of the CyPy•TCA H-bond complex causes a general slowdown of the overall rotational motion with a very slight increase in its anisotropy (7 ps for rotation and 17 ps for tumbling, respectively). The results are compared with similar data on H-bonding in pyridine N-oxide/acid systems.

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Section: Resultssupporting

confidence: 69%

CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

Balevičius¹,

Fueß²

2005

Lith. J. Phys.

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“…Simulations of the spectrum taking all possible proton-proton dipolar contacts into account support the concerted double proton transfer mechanism. Further evidence for a concerted motion of two hydrogen atoms is also provided by 17 O nuclear quadrupole resonance (NQR) studies of carboxylic acids [26][27][28][29]. The NQR spectrum reveals only two oxygen sites confirming the equivalence of the two hydrogen bonds and the evolution with temperature provides an estimate of the energy asymmetry.…”

Section: Nmr Spectroscopymentioning

confidence: 89%

Quantum tunnelling in the hydrogen bond

Horsewill

2008

Progress in Nuclear Magnetic Resonance Spectroscopy

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“…5. The NQR and structural data are taken from the following references: quinolinic acid [9,17], maleic acid [8,18], squaric acid [6,4], acetic acid [8,19], formic acid [8,20], 2-nitrobenzoic acid [10,21], acrylic acid [8,22], a-and b-oxalic acid [8,23,24], fumaric acid [8,25] and chloranilic acid [7,26].…”

mentioning

confidence: 99%

¹⁷O NQR and ¹³C NMR study of hydrogen‐bonded organic ferroelectric croconic acid

Seliger

Plavec

Šket

et al. 2011

Physica Status Solidi (b)

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The 1H17O nuclear quadrupole double resonance spectrum and the 13C CP/MAS NMR spectrum of polycrystalline croconic acid, H2C5O5, have been studied at room temperature. Croconic acid has been recently shown to have the highest switchable spontaneous polarization of all organic ferroelectrics and stays polarized up to the decomposition point at around 450 K. Both the 13C NMR and the 17O nuclear quadrupole resonance (NQR) spectra show that there are five crystallorgaphically non‐equivalent carbon and oxygen positions for a given molecule and that therefore the two OH…O bonds are non‐equivalent. From the dipolar structure of the 17O quadrupole resonance spectra the OH distance is determined as being 0.099 ± 0.001 nm in both hydrogen bonds. The large 17O quadrupole coupling constant at the COH as well as at the CO…H oxygen position and the short OH distance demonstrate that the OH…O hydrogen bonds are strongly asymmetric. A correlation of the 17OH…O and OH…17O quadrupole coupling constants versus the O…O distance has been observed in several organic acids. The data for croconic acid significantly deviate from this correlation, what may be the result of the strong long range ferroelectric ordering which influences the electron distribution in the hydrogen bonds.

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1H–17O Nuclear-Quadrupole Double-Resonance Study of Hydrogen Disorder in 2-Nitrobenzoic Acid

Cited by 16 publications

References 13 publications

CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

Quantum tunnelling in the hydrogen bond

¹⁷O NQR and ¹³C NMR study of hydrogen‐bonded organic ferroelectric croconic acid

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1H–17O Nuclear-Quadrupole Double-Resonance Study of Hydrogen Disorder in 2-Nitrobenzoic Acid

Cited by 16 publications

References 13 publications

CP/MAS,13C and17O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

CP/MAS,13C and17O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

Quantum tunnelling in the hydrogen bond

17O NQR and 13C NMR study of hydrogen‐bonded organic ferroelectric croconic acid

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CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

CP/MAS,¹³C and¹⁷O NMR studies of proton transfer and dynamics of cyanopyridine hydrogen-bond complex with trichloroacetic acid in crystal and in solution

¹⁷O NQR and ¹³C NMR study of hydrogen‐bonded organic ferroelectric croconic acid