The data analysis capabilities of the MestReNova NMR software makes
processing and analyzing complex reaction mixture data a snap! Stacked
plots are quick and easy and the integration routines rapidly process
the peak areas into reaction profiles. Further steps allow the
exponential fitting of the reaction profiles to yield kinetic
information. Here are a few examples of the data visualization and rapid
reaction profiling on a 60 MHz 1H NMR series obtained every 10 seconds
(1 pulse) over the course of 25 minutes – the reaction is the
esterification of tert-butanol with acetic anhydride in the presence of
acid.
Figure 1: Stacked Plot of the Aliphatic Region of the Spectrum with Reaction Chemistry Protons Identified
Figure 2: Stacked Plot – Full Spectrum – Reaction Monitoring – 146 Spectra – 10 Seconds Apart
Figure 3: Angled Stack Plot – Acetic Anhydride and tert-Butanol – Real Time Reaction Monitoring by 1H NMR at 60 MHz
Figure 4: Stacked and Whitewashed Plot of 1H NMR data at 60 MHz – Real
Time Reaction Monitoring of Acetic Anhydride with tert-Butanol
Figure 5: Data Analysis Tool and production of reaction profiles.
The MNova data analysis tools allow the user to integrate NMR
reaction peaks and automatically plots and fits them to exponential time
constants allowing detailed kinetics to be extracted rapidly and easily
from the data. What used to take hours of lining up ascii spectra in
excel or other software now literally takes seconds. The integration is
segmented in such a manner that integrals can be made to track with
shifting resonances, for example labile protons effected by pH.
The AspectItalia 60 MHz NMR system allows real time analysis of
reactions with high S/N on single pulses. half height linewidths of 1-2
Hz (15-30 ppb) are possible on static reaction setups and 2-5 Hz (30 –
80 ppb) are possible with flowing reactions at rates of 1-20 ml/min.