2H NMR Relaxation and Line Shape Analysis of Water in a Lamellar Liquid Crystalline Phase Formed by Dodecyldimethylamineoxide (DDAO) and2H2O

2001 ◽  
Vol 105 (50) ◽  
pp. 12524-12528 ◽  
Author(s):  
Tobias Sparrman ◽  
Per-Olof Westlund
Keyword(s):  
Shape Analysis ◽  
Crystalline Phase ◽  
Line Shape ◽  
Liquid Crystalline ◽  
Nmr Relaxation ◽  
Liquid Crystalline Phase ◽  
2H Nmr ◽  
Line Shape Analysis

scholarly journals Protein Dynamics in the Solid State from 2H NMR Line Shape Analysis: A Consistent Perspective

2015 ◽  
Vol 119 (7) ◽  
pp. 2857-2868 ◽  
Author(s):  
Eva Meirovitch ◽  
Zhichun Liang ◽  
Jack H. Freed
Keyword(s):  
Solid State ◽  
Protein Dynamics ◽  
Shape Analysis ◽  
Line Shape ◽  
2H Nmr ◽  
Line Shape Analysis

Backbone motions in a crystalline protein from field-dependent2H-NMR relaxation and line-shape analysis

Biopolymers ◽  
2000 ◽  
Vol 53 (1) ◽  
pp. 9-18 ◽  
Author(s):  
James W. Mack ◽  
M. G. Usha ◽  
Joanna Long ◽  
Robert G. Griffin ◽  
R. J. Wittebort
Keyword(s):  
Shape Analysis ◽  
Line Shape ◽  
Nmr Relaxation ◽  
Line Shape Analysis

Determination of the Accurate Values of the Rate Constant and Thermodynamic Parameters for the Rotation About the C(sp2)-C(aryl) Bond; Adamantan-1-yl 3-Bromo-2,4,6-trimethylphenyl Ketone

1998 ◽  
Vol 63 (7) ◽  
pp. 955-966
Author(s):  
Eva Přibylová ◽  
Miroslav Holík
Keyword(s):  
Thermodynamic Parameters ◽  
Shape Analysis ◽  
Rate Constants ◽  
Line Shape ◽  
Microsoft Excel ◽  
Hindered Rotation ◽  
H Nmr ◽  
Line Shape Analysis ◽  
Coalescence Temperature

Four programs for the 1H NMR line shape analysis: two commercial - Winkubo (Bruker) and DNMR5 (QCPE 165) and two written in our laboratory - Newton (in Microsoft Excel) and Simtex (in Matlab) have been tested in order to get highly accurate rate constants of the hindered rotation about a single bond. For this purpose four testing criteria were used, two of them were also developed by us. As supplementary determinations the rate constants obtained for the coalescence temperature and for the thermal racemization of chromatographically separated enantiomers were used which fitted well the temperature dependence of the rate constants determined by the line shape analysis. As a test compound adamantan-1-yl 3-bromo-2,4,6-trimethylphenyl ketone was prepared and studied. It was shown that supermodified simplex method used in our algorithm (Simtex), though time consuming, gives the most accurate values of the rate constants and consequently the calculated thermodynamic parameters Ea, ∆H≠, and ∆S≠ lay in relatively narrow confidence intervals.

scholarly journals Electron transfer studies of a conventional redox probe in human sweat and saliva bio-mimicking conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Krishnaveni ◽  
V. Ganesh
Keyword(s):  
Electron Transfer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Redox Couple ◽  
Liquid Crystalline Phase ◽  
Transfer Reactions ◽  
Redox Probe ◽  
Human Sweat

AbstractModern day hospital treatments aim at developing electrochemical biosensors for early diagnosis of diseases using unconventional human bio-fluids like sweat and saliva by monitoring the electron transfer reactions of target analytes. Such kinds of health care diagnostics primarily avoid the usage of human blood and urine samples. In this context, here we have investigated the electron transfer reaction of a well-known and commonly used redox probe namely, potassium ferro/ferri cyanide by employing artificially simulated bio-mimics of human sweat and saliva as unconventional electrolytes. Typically, electron transfer characteristics of the redox couple, [Fe(CN)6]3−/4− are investigated using electrochemical techniques like cyclic voltammetry and electrochemical impedance spectroscopy. Many different kinetic parameters are determined and compared with the conventional system. In addition, such electron transfer reactions have also been studied using a lyotropic liquid crystalline phase comprising of Triton X-100 and water in which the aqueous phase is replaced with either human sweat or saliva bio-mimics. From these studies, we find out the electron transfer reaction of [Fe(CN)6]3−/4− redox couple is completely diffusion controlled on both Au and Pt disc shaped electrodes in presence of sweat and saliva bio-mimic solutions. Moreover, the reaction is partially blocked by the presence of lyotropic liquid crystalline phase consisting of sweat and saliva bio-mimics indicating the predominant charge transfer controlled process for the redox probe. However, the rate constant values associated with the electron transfer reaction are drastically reduced in presence of liquid crystalline phase. These studies are essentially carried out to assess the effect of sweat and saliva on the electrochemistry of Fe2+/3+ redox couple.

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