Distance Measurements by Dipolar Recoupling Two-Dimensional Solid-State NMR
| Autor: | Suzanne Kiihne, D. M. Gregory, J. C. Shiels, J. A. Stringer, Gary P. Drobny, M. A. Mehta |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 102:2274-2282 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp9721412 |
| Popis: | We present a two-dimensional NMR technique for the measurement of dipolar couplings in polycrystalline solids. This experiment is fully transverse and uses a windowless dipolar recoupling pulse sequence (DRAWS, described in Gregory, D. M.; et al. Chem. Phys. Lett. 1995, 246, 654−663) to effect coherence transfer. Direct, internuclear coherence transfer produces negative cross-peaks in the 2D spectrum. Cross-peak development and experimental requirements for obtaining distances from the two-dimensional solid-state NMR spectra of two- and three-spin systems are discussed, and demonstrations are shown for thymidine-2,4-13C2 and l-alanine-13C3. Internuclear distances are derived by comparison of experimental cross-peak buildup curves with numerical simulations. In the three-spin system, indirect coherence-transfer mechanisms prohibit the interpretation of buildup curves as due to isolated spin pair interactions and limit the accuracy of some distance measurements. This 2D technique can also be used for spectr... |
| Databáze: | OpenAIRE |
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