Bestimmung kernresonanzspektroskopischer Parameter durch Lorentz-Kurven-Form-Analyse: I [C6F5Si(CH3)2]2 / Determination of NMR Parameters by Lorentzian-Line-Shape-Analysis I: [C6F5Si(CH3)2]2

1975 ◽  
Vol 30 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Gerhard Hägele ◽  
Volker Lueg

Abstract The set-up of digital-out-put for HR-CW-NMR-spectrometers and computer-programs suitable for Lorentzian-line-shape-analysis is reported. The values for 5JHF AND 6JHF IN [C6F5Si(CH3)2]2 are determined.

1998 ◽  
Vol 63 (7) ◽  
pp. 955-966
Author(s):  
Eva Přibylová ◽  
Miroslav Holík

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.


1997 ◽  
Vol 07 (C1) ◽  
pp. C1-443-C1-444
Author(s):  
A. K. Srivastava ◽  
M. J. Patni ◽  
B. K. Chaturvedi

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