An Inversion Recovery NMR Kinetics Experiment

Abstract

A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this article will enable instructors to use inversion recovery as a laboratory activity in applied NMR classes and provide research students with a convenient template with which to acquire inversion recovery data on research samples.

Complexation and Catenation in Aqueous Media Using a Self‐Assembled PdII Metallacyclic Receptor

“…Relaxation times ( T 1 ) for the resonances of interest were measured before the magnetization transfer experiment by using the inversion recovery method. The magnetization transfer data were fitted by using the program CIFIT22 to obtain the reported rate constants 23…”

“…The magnetization transfer data were fitted by using the program CIFIT [22] to obtain the reported rate constants. [23]…”

Teaching indicators to unravel the kinetic features of host–guest inclusion complexes

“…10,11 The design of out-of-equilibrium systems also requires knowledge of both K a values and rate constants. [12][13][14][15] However, except for CEST-active 3 or slowly equilibrating systems that can be monitored by NMR (e.g., DOSY, EXSY, inversion recovery), 1,[16][17][18][19][20] kinetic rate constants of supramolecular systems are experimentally mostly only available for chromophoric or emissive systems. 2,4,[21][22][23] These experiments are typically conducted as time-resolved direct host-guest binding titration assays, herein abbreviated as kinDBA (Fig.…”

Anion-Abstraction Catalysis: The Cooperative Mechanism of α-Chloroether Activation by Dual Hydrogen-Bond Donors

“…In order to monitor chemical exchange on the slower spin–lattice relaxation ( T 1 ) timescale, we applied a selective inversion–recovery (SIR) experiment. 10,11 Competitive magnetization transfer by nuclear Overhauser effect (nOe) pathways could be minimized by studying the epimerization of α-chloroisochroman- d 3 (as a mixture of diastereomers 5a and 5b , Figure 1A) as a proxy for racemization. With these considerations, chemical exchange could be readily detected in the presence of catalyst.…”