CARBON 13 SPIN-LATTICE RELAXATION TIMES OF THE INCLUSION COMPLEX OF β-CYCLODEXTRIN WITH SULFATHIAZOLE IN AQUEOUS SOLUTION

14 N n.m.r. spin-lattice relaxation times of four metal nitrate salts were measured as a function of concentration in aqueous solution. The concentration dependence of T1 was attributed to the formation of ion pairs with increasing concentration in these solutions. The T1 data, allowing for viscosity corrections, were treated by a two-state model of 'free' and 'bound' nitrate ions and to both possibilities of slow and fast exchange between the two states. In the equilibrium expressions estimates of the relevant activity coefficients were included. The slow nitrate exchange mechanism was favoured and the values obtained for this particular mechanism compared well with those derived from alternative measurements.

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N.M.R. studies on myelin basic protein. IV. 13C N.M.R. of the peptide encephalitogenic in the guinea pig

Australian Journal of Chemistry ◽

10.1071/ch9802411 ◽

1980 ◽

Vol 33 (11) ◽

pp. 2411 ◽

Cited By ~ 3

Author(s):

SA Margetson ◽

WJ Moore

Keyword(s):

Aqueous Solution ◽

Guinea Pig ◽

Basic Protein ◽

Relaxation Times ◽

Lattice Relaxation ◽

Spin Lattice Relaxation ◽

Side Chain ◽

Aromatic Rings ◽

Ph Titration ◽

Spin Lattice

The encephalitogenic nonapeptide Phe1-Ser2-Trp3-Gly4-Ala5-Glu6-Gly7-Gln8- Lys9 and its [D-Ala5] analogue have been studied in aqueous solution by 13C n.m.r. spectroscopy. The resonances of all the carbons have been assigned and their pH profiles measured. The expected conformational differences are indicated by only subtle differences in long-range pH titration shifts. The spin-lattice relaxation times T1 of all the protonated carbons of the [L-Ala5] nonapeptide have been measured at 25°C. Analysis of these data in terms of effective correlation times for side-chain mobilities suggests restricted motions for the side chains of Glu6 and Gln8 and the aromatic rings of Phe1 and Trp3.

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A Carbon-13 Spin-Lattice Relaxation Studies of Simple Alkylsulfates and Alkylsulfonates in Aqueous Solution

Zeitschrift für Naturforschung A ◽

10.1515/zna-1983-1018 ◽

1983 ◽

Vol 38 (10) ◽

pp. 1149-1151

Author(s):

Kazuhiro Matsushita ◽

Yukimasa Terada ◽

Tadayoshi Yoshida ◽

Hirofumi Okabayashi

Keyword(s):

Aqueous Solution ◽

Relaxation Times ◽

Lattice Relaxation ◽

Spin Lattice Relaxation ◽

Polar Group ◽

Progressive Decrease ◽

Methyl Group ◽

Critical Micelle Concentrations ◽

Spin Lattice ◽

Relaxation Studies

Abstract The C-13 spin-lattice relaxation times (T1) of a series of short-chain n-alkylsulfates and sulfonates in D2O solutions were measured at various concentrations. Even for ethylsulfate and n-propylsulfonate ions, inflections, due to association, in the reciprocal of the T1 vs. the inverse concentration plots were observed. The critical micelle concentrations (CMC's) of ethyl and butylsulfates are 3.0 and 2.5 mol/l, respectively, and those of propyl and butylsulfonate 2.3 and 1.9 mol/l, respectively. For the simple alkylsulfates, below the CMC a progressive decrease in T1 from the terminal methyl group towards the polar group was observed.

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Molecular Mobility of Sucrose in Aqueous Solution Studied by 13C NMR Relaxation

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-5-601 ◽

1993 ◽

Vol 48 (5-6) ◽

pp. 407-413 ◽

Cited By ~ 10

Author(s):

D. Girlich ◽

H.-D Lüdemann

Keyword(s):

Aqueous Solution ◽

Concentration Dependence ◽

Relaxation Times ◽

Nmr Relaxation ◽

Lattice Relaxation ◽

Rotational Dynamics ◽

Spin Lattice Relaxation ◽

Rotational Mobility ◽

Spin Lattice ◽

The Ideal

Abstract From the temperature and concentration dependence of the 13C spin lattice relaxation times of the 12 carbon atoms of the sucrose molecule the rotational dynamics of the sugar molecules are determined. No indication for conformational mobility of the rings is found. The exocyclic hydroxymethyl groups possess extra mobility. The models used for the description are critically discussed. The temperature dependence of the rotational mobility is described by a VTF equation. The concentration dependence of the ideal glass transition temperature To for this mobility is derived.

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