Temperature dependence and resonance assignment of13C NMR spectra of selectively and uniformly labeled fusion peptides associated with membranes

2004 ◽  
Vol 42 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Michele L. Bodner ◽  
Charles M. Gabrys ◽  
Paul D. Parkanzky ◽  
Jun Yang ◽  
Craig A. Duskin ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Resonance Assignment ◽  
Nmr Spectra ◽  
Fusion Peptides

13C NMR-spektroskopische Untersuchungen an Äthylaluminiumverbindungen / 13C NMR Spectroscopic Investigations of Ethylaluminium Compounds

1976 ◽  
Vol 31 (6) ◽  
pp. 730-736 ◽  
Author(s):  
R. Rottler ◽  
C. G. Kreiter ◽  
G. Fink
Keyword(s):  
Temperature Dependence ◽  
Exchange Reaction ◽  
13C Nmr ◽  
Line Shape ◽  
Nmr Spectra ◽  
Exchange Process ◽  
Kcal Mole ◽  
Line Shapes ◽  
Calculated Line ◽  
C Nmr

The 13C NMR spectra of the ethylaluminium compounds [Al(C2H5)xCl3_x]2 x = 1, 1,5, 2 and 3 are presented and factors governing the temperature dependence of the line shape are discussed. The exchange reaction of terminal ethyl groups for chlorine ligands and ethyl ligands, resp., in ethylaluminium-sesquichloride was investigated by fitting the calculated line shapes to the observed spectra.The energy of activation of this exchange process was determined as to be 12,3 ‡ 1,5 kcal/mole. The synthesis of 13C2-[Al(C2H5)Cl2]2 is described.

11B-NMR-Spektren von Alkyl-, Halogeno- und Rhodanohydrohexaboraten / 11B NMR Spectra of Alkyl-, Halogeno- and Rhodanohydrohexaborates

1988 ◽  
Vol 43 (12) ◽  
pp. 1647-1652 ◽  
Author(s):  
A. Heinrich ◽  
W. Preetz ◽  
H. C. Marsmann
Keyword(s):  
Temperature Dependence ◽  
Nmr Spectra ◽  
Spin Coupling ◽  
Bronsted Acids ◽  
11B Nmr ◽  
Spin Spin Coupling

Abstract The temperature dependence of the 11B NMR spectra of the monosubstituted and protonated c/oso-hexaborates RB6H6-, R=CH3, C2H5, C3H7, C4H9 C8H17, (SCN)B6H6- and XB6H6 X = Cl. Br. I, has been determined in the range 180-300 K. The extra proton migrates at higher temperatures intramolecularly, probably across the edges of the B6 core. The extra proton is fixed to a facet of the octahedron below the coalescence temperatures 240 K (RB6H6-) and 210 K (XB6H6-) as recognized by the splitting of the signal of the equatorial B atoms due to the lowering of the symmetry from C4v to Cs . From the spin-spin coupling it can be deduced that the proton prefers with the softer Brönsted acids RB6H6- facets adjacent to the substituent, while with the stronger Brönsted acids XB6H6- facets including the antipodal B atom are occupied.

Notiz: Temperature Dependence of the Proton NMR Spectra of Bitumen

1997 ◽  
Vol 52 (4) ◽  
pp. 373-376 ◽  
Author(s):  
J. Dolinšek ◽  
G. Lahajnar ◽  
B. Marin ◽  
J. Pirš ◽  
A. Sepe ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Transition Region ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Proton Nmr ◽  
Significant Difference ◽  
Different Origin

Abstract The temperature dependence of the proton NMR spectra of bitumen samples of different origin and quality has been measured between 400 K and 80 K. Whereas the linewidths of different samples are essentially identical above 340 K and below 240 K, there is a significant difference in the linewidth transition region around room temperature.The results show that it is possible to discriminate between bitumen samples of different composition and quality by simply measuring the proton NMR linewidth at room temperature.

Non-Markovian Dynamic And Nmr Spectra In Solids

2004 ◽  
Vol 59 (7-8) ◽  
pp. 501-504 ◽  
Author(s):  
M. Olszewski ◽  
N. A. Sergeev ◽  
A.V. Sapiga
Keyword(s):  
Markov Model ◽  
Temperature Dependence ◽  
Absorption Spectra ◽  
Nmr Spectra ◽  
Molecular Motion ◽  
Molecular Motions ◽  
Dichotomic Noise

The influence of non-Markov molecular motions on NMR absorption spectra has been investigated. It has been shown that the simple non-Markov model of water molecular motion with fluctuations driven by dichotomic noise very well explains the observed temperature dependence of NMR spectra in the mineral natrolite. - PACS number: 05.40.+j, 33.25.+k, 76.20.+q

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