Measurement of 13C chemical shifts in solids

Earl, William L.; VanderHart, David L.

doi:10.1016/0022-2364(82)90236-0

Cited by 194 publications

(223 citation statements)

References 30 publications

Supporting

Mentioning

219

Contrasting

Order By: Relevance

“…Several samples required the use of the flipback (21) or TOSS (22) pulse sequences. Chemical shifts were referenced to external solid adamantane, which has shifts of 38.56 pprn (CH2) and 29.50 pprn (CH) with respect to TMS (23). All spectra were recorded at ambient temperatures (20 2 2°C).…”

Section: Methodsmentioning

confidence: 99%

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

Penner¹,

Wasylishen²

1989

Can. J. Chem.

View full text Add to dashboard Cite

The carbon-13 chemical shifts of several 1,4-disubstituted benzenes in the solid state are reported. At least one of the substituents is unsymmetrical and in most cases this leads to different 13C chemical shifts of C-2 and C-6 and in some cases to different shifts for C-3 and C-5. The 13c chemical shifts observed in the solid state are compared with those measured in solution and, where possible, with those obtained in low temperature solution studies where internal rotation of the unsymmetrical substituent is slow on the I3C chemical shift time scale. Agreement between the chemical shifts observed in the solid state and solution is excellent. The potential application of CP/MAS nuclear magnetic resonance in deducing the conformation of benzene derivatives with two unsymmetrical substituents is discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

Penner¹,

Wasylishen²

1989

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…The quaternary carbon resonances were assigned using the pulse sequence of Opella and Frey (1 7). Chemical shifts were referenced to external adamantane (18 assignment of the C, , and Cp, signals in the carbon-13 spectrum and their respective pairs of attached protons in the 'H spectrum. To determine whether any carbon-13 resonance signals cross over the entire pH range, a I3C nmr titration of carnosine was carried out in which the resonance signals were recorded at increments of 0.5 pH units.…”

Section: Methodsmentioning

confidence: 99%

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

Friedrich¹,

Wasylishen²

1986

Can. J. Chem.

View full text Add to dashboard Cite

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.

show abstract

“…The use of an external standard for referencing solid-state 13 C MAS has been studied over the years (28)(29)(30)(31)(32)(33). More recently, Morcombe and Zilm (18) have shown that adamantane can easily be used to reference 13 C MAS spectra externally with a precision of +/-0.03 ppm.…”

Section: Masmentioning

confidence: 99%

Setting up ¹³C CP/MAS experiments

Taylor

2004

Concepts Magnetic Resonance

View full text Add to dashboard Cite

The 13C cross‐polarization (CP) technique combined with magic angle spinning (MAS) has become one of the more commonly performed solid‐state nuclear magnetic resonance (NMR) experiments. The basics of initially setting up the experiment are given and used to illustrate such NMR phenomena as rotational echoes, homogeneous and inhomogeneous interactions, continuous wave 1H decoupling, and coupling of quadrupolar 14N nuclei to 13C nuclei. The polarization transfer from the protons to the carbons is described briefly with the usual thermodynamic and quantum mechanical models. The setup and use of the experiment for routine analyses are discussed. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson 22A: 37–49, 2004.

show abstract

Measurement of 13C chemical shifts in solids

Cited by 194 publications

References 30 publications

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

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

Setting up ¹³C CP/MAS experiments

Contact Info

Product

Resources

About

Measurement of 13C chemical shifts in solids

Cited by 194 publications

References 30 publications

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

A carbon-13 CP/MAS nuclear magnetic resonance study of several 1,4-disubstituted benzenes in the solid state

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

Setting up 13C CP/MAS experiments

Contact Info

Product

Resources

About

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

Setting up ¹³C CP/MAS experiments