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arXiv · 2208.09213

Cross-correlation effects in the solution NMR spectra of near-equivalent spin-1/2 pairs

James W. Whipham·Gamal A. I. Moustafa·Mohamed Sabba·Weidong Gong·Christian Bengs·Malcolm H. Levitt
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Abstract

The NMR spectra of spin-1/2 pairs contains four peaks, with two inner peaks much stronger than the outer peaks in the near-equivalence regime. We have observed that the strong inner peaks have significantly different linewidths, when measurements were performed on a 13C2-labelled triyne derivative. This linewidth difference may be attributed to strong cross-correlation effects. We develop the theory of cross-correlated relaxation in the case of near-equivalent homonuclear spin-1/2 pairs, in the case of a molecule exhibiting strongly anisotropic rotational diffusion. Good agreement is found with the experimental NMR lineshapes.

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James W. Whipham, Gamal A. I. Moustafa, Mohamed Sabba, Weidong Gong, Christian Bengs, Malcolm H. Levitt. 2022-08-19. Cross-correlation effects in the solution NMR spectra of near-equivalent spin-1/2 pairs. https://doi.org/10.1063/5.0107221

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