Influence of nitrogen-14 on carbon-13 NMR spectra of solids

Hexem, J. G.; Frey, M. H.; Opella, Stanley J.

doi:10.1021/ja00391a057

Cited by 167 publications

(70 citation statements)

References 2 publications

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“…Under conditions where the quadrupolar interaction may be treated as a perturbation of the Zeeman interaction, the magnitude of the splitting observed in the MAS spectrum is directly proportional to e Z q e / h and R, but inversely proportional to the square of the strength of the applied field Bo. This phenomenon has been observed by numerous workers and is well understood (14)(15)(16)(17)(18)(19).…”

Section: Methodsmentioning

confidence: 61%

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A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

Dickson¹,

McKinnon²,

Britten³

et al. 1987

Can. J. Chem.

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The static 13C nmr powder pattern for solid ammonium thiocyanate is analyzed to obtain the 13C chemical shielding anisotropy, 321 ± 7 ppm, and the 13C–14N dipolar splitting, 1295 ± 25 Hz. Slow magic angle spinning 15N nmr experiments are analyzed to obtain a nitrogen chemical shielding anisotropy of 415 ± 15 ppm. The 13C–14N dipolar splitting leads to an effective C—N bond length of 1.19 ± 0.01 Å, in good agreement with the value of 1.176 Å reported from accurate X-ray and neutron crystallographic studies. In solid NH4NCS absolute values of the average shielding constants [Formula: see text] and ct[Formula: see text] are 52 and 34 ppm, respectively. Comparison of calculated and observed [Formula: see text] values indicates that intermolecular interactions decrease the 13C and 15N shielding constants by approximately 10 and 30 ppm, respectively.

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Section: Methodsmentioning

confidence: 61%

“…The observed 13C nrnr spectrum was an asymmetric doublet and was analyzed using known procedures (14)(15)(16)(17)(18)(19). The spinning sidebands observed in the I5N nrnr spectra of NH4NCS obtained with slow MAS were analyzed to obtain the I5N CSA using the '~u t h o r to whom all correspondence may be addressed.…”

Section: Introductionmentioning

confidence: 99%

A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

Dickson¹,

McKinnon²,

Britten³

et al. 1987

Can. J. Chem.

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“…The resonance dominating the CP/MAS spectrum at b = 168.2 is that of the intercalating formamide bonded at each end. Broadening of this x3C resonance is likely due to ~4N quadrupolar coupling, as described by Hexem et al (1981).…”

Section: Cp/mas Dd/masmentioning

confidence: 85%

Interpretation of Solid state ¹³C and ²⁹Si Nuclear Magnetic Resonance Spectra of Kaolinite Intercalates

Thompson

1985

Clays and clay miner.

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Abstract--~3C and 295i nuclear magnetic resonance spectroscopy with magic-angle spinning bas been used to study the short-range ordering and bonding in the structures of intercalates of kaolinite with formamide, hydrazine, dimethyl sulfoxide (DMSO), and pyridine-N-oxide (PNO). The 29Si chemical shift indicated decreasing levels of bonding interaction between the silicate layer and the intercalate in the order: kaolinite: formamide (5 = -91.9, ppm relative to tetramethylsilane), kaolinite: hydrazine ( -92.0), kaolinite: DMSO (-93.1). The 29Si signal of the kaolinite: PNO intercalate (-92.1) was unexpectedly deshielded, possibly due to the aromatic nature of PNO. The degree of three-dimensional ordering of the structures was inferred from the 295i signal width, with the kaolinite: DMSO intercalate displaying the greatest ordering and kaolinite : hydrazine the least. ~3C resonances of intercalating organic molecules were shifted downfield by as much as 3 ppm in response to increased hydrogen bonding after intercalation, and in the kaolinite : DMSO intercalate the two methyl-carbon chemical environments were non-equivalent (6 = 43.7 and 42.5).

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“…In two independent X-ray crystallography studies (10, 11) it was determined that carnosine crystallizes in the monoclinic C 2 space group which indicates that all carnosine molecules are equivalent in the solid. W e attribute the doublets to 14~-13c dipolar coupling, which is not averaged to zero because the '% quadrupolar interaction is comparable in magnitude to the "N Zeeman interaction (53)(54)(55)(56). The magnitude of the apparent splitting is proportional to the dipolar interaction, ~~~~h / 4~r~( r~~) 3 , the quadrupolar interaction, e2qQ/ h, its orientation with respect to rm, and the magnitude of the Zeeman interaction, B,.…”

Section: Solid I3c Spectrum Of Carnosinementioning

confidence: 99%

A ¹H and ¹³C nuclear magnetic resonance study of carnosine

Friedrich¹,

Wasylishen²

1986

Can. J. Chem.

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The proton and carbon-13 resonance signals of carnosine (β-alanyl-L-histidine) were unambiguously assigned using a variety of nmr techniques including proton–carbon chemical shift correlations, titrations of nmr chemical shifts, coupling constants, and isotope shifts. From the 13C nmr titration, carnosine's three pKa values were estimated to be 2.7, 7.1, and 10.6, and it was found that the imidazole ring existed predominantly as the 3-H tautomer in basic solution. Conformational information about the Cα—Cβ bond and about the N—Cα bond was deduced from observed 3J(C,H) and 3J(H,H) values. The 13C nmr spectrum of carnosine in solution is also compared with that obtained for a solid sample.

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Influence of nitrogen-14 on carbon-13 NMR spectra of solids

Abstract: Resonances from carbons bonded to nitrogen are often broadened and split into asymmetric doublets in 13C NMR spectra of polycrystalline organic molecules obtained with proton decoupling and magic-angle sample spinning.

Cited by 167 publications

References 2 publications

A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

Interpretation of Solid state ¹³C and ²⁹Si Nuclear Magnetic Resonance Spectra of Kaolinite Intercalates

A ¹H and ¹³C nuclear magnetic resonance study of carnosine

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Influence of nitrogen-14 on carbon-13 NMR spectra of solids

Abstract: Resonances from carbons bonded to nitrogen are often broadened and split into asymmetric doublets in 13C NMR spectra of polycrystalline organic molecules obtained with proton decoupling and magic-angle sample spinning.

Cited by 167 publications

References 2 publications

A 13C and 15N nuclear magnetic resonance study of solid ammonium thiocyanate

A 13C and 15N nuclear magnetic resonance study of solid ammonium thiocyanate

Interpretation of Solid state 13C and 29Si Nuclear Magnetic Resonance Spectra of Kaolinite Intercalates

A 1H and 13C nuclear magnetic resonance study of carnosine

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A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

A ¹³C and ¹⁵N nuclear magnetic resonance study of solid ammonium thiocyanate

Interpretation of Solid state ¹³C and ²⁹Si Nuclear Magnetic Resonance Spectra of Kaolinite Intercalates

A ¹H and ¹³C nuclear magnetic resonance study of carnosine