An Examination of Factors Influencing Small Proton Chemical Shift Differences in Nitrogen-Substituted Monodeuterated Methyl Groups

Monodeuterated methyl groups have previously been demonstrated to provide access to long-lived nuclear spin states. This is possible when the CH2D rotamers have sufficiently different populations and the local environment is chiral, which foments a non-negligible isotropic chemical shift difference between the two CH2D protons. In this article, the focus is on the N-CH2D group of N-CH2D-2-methylpiperidine and other suitable CH2D-piperidine derivatives. We used a combined experimental and computational approach to investigate how rotameric symmetry breaking leads to a 1H CH2D chemical shift difference that can subsequently be tuned by a variety of factors such as temperature, acidity and 2-substituted molecular groups.

A concise approach for determining the relative configuration of H-7 and H-8 in 8,4′-oxyneolignans by 1H NMR spectroscopy

The chemical shift difference between H-9a and H-9b can be used to accurately and rapidly determine the relative configuration of H-7 and H-8 in three types of 8,4′-oxyneolignan glucosides.

The Role of the Chemical Shift Difference in a Two-Site Exchange Model Under an On-Resonance Spin-Lock RF Field

The manuscript investigates the role of the chemical shift difference between two exchanging pools under a spin-lock RF field. The results demonstrate that the width of the dispersion of R1rho is determined mainly by the chemical shift difference when the exchange is slow. This work may give a new insight into the spin dynamics under a spin-lock condition and the results may be relevant to the fields using the spin-lock technique, such as protein NMR and MRI contrast.<br>

The Role of the Chemical Shift Difference in a Two-Site Exchange Model Under an On-Resonance Spin-Lock RF Field

The manuscript investigates the role of the chemical shift difference between two exchanging pools under a spin-lock RF field. The results demonstrate that the width of the dispersion of R1rho is determined mainly by the chemical shift difference when the exchange is slow. This work may give a new insight into the spin dynamics under a spin-lock condition and the results may be relevant to the fields using the spin-lock technique, such as protein NMR and MRI contrast.<br>

Direct detection of lysine side chain NH3+ in protein–heparin complexes using NMR spectroscopy

Identification of the lysine side chain NζH3+ peak in the HISQC spectrum and Nζ chemical shift difference between the free and heparin-bound forms are useful methods for identifying binding-interface lysines in protein–heparin complexes.

Temperature Dependent Magnetic Susceptibility and Equilibrium Studies in Solution: Evans’s Method

The chemical shift in a solvent caused by the presence of a paramagnetic species and the temperature dependence of the chemical shift difference to determine the temperature dependent magnetic susceptibility can be studied using Evans method. The method is very useful because a common NMR instrument, easily accessible in a department of chemistry, allows the accurate measurement of paramagnetic susceptibilities. The present review highlights planar (S = 0) and octahedral (S = 1) forms of Ni(II) complexes are in equilibrium and has been followed in the temperature range 298 − 338 K by 1H NMR technique using the protocol of Evans’s method.

Long-lived nuclear spin states in monodeuterated methyl groups

It is possible to access long-lived nuclear singlet order in monodeuterated methyl groups, in the case that a significant chemical shift difference exists between the CH2D protons.