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. 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.įigure 1: Stacked Plot of the Aliphatic Region of the Spectrum with Reaction Chemistry Protons Identifiedįigure 2: Stacked Plot – Full Spectrum – Reaction Monitoring – 146 Spectra – 10 Seconds Apartįigure 3: Angled Stack Plot – Acetic Anhydride and tert-Butanol – Real Time Reaction Monitoring by 1H NMR at 60 MHzįigure 4: Stacked and Whitewashed Plot of 1H NMR data at 60 MHz – Real Time Reaction Monitoring of Acetic Anhydride with tert-Butanolįigure 5: Data Analysis Tool and production of reaction profiles. Further steps allow the exponential fitting of the reaction profiles to yield kinetic information. The methods used for processing T1 relaxation data in MNova can be applied to other stacked pseudo-2d experiments, like kinetics, diffusion, T2, T1rho, etc.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. Also, we use MestreNova for data processing. This video goes through the concept of T1 relaxation, and how to measure T1 for each particular 1H environment.

For organic chemists, often the most useful reason for knowing your T1 (longitudinal) relaxation times is so that you can obtain clean integrations - If you have different types of 1H environments, and they have different relaxation properties, it is possible that your 1H integrals may not come out to clean numbers (For example, 2:3 ratio between a CH2 and CH3 group). Typically if one wants quantitative integrations, one must wait at least 5 times the T1 of your slowest relaxing protons.

Have you ever wondered why your 1H integrals sometimes don’t come out to clean numbers? T1 (Longitudinal) relaxation is the constant required for your nuclear spins to relax back to equilibrium by a factor of e.

4) T1 Relaxation Measurement – Concept, Data collection, Data Analysis

Mestrenova stacked spectra