Through-space 11 B- 27 Al correlation: Influence of the recoupling channel

• Published in: Magnetic resonance in chemistry Vol. 59; no. 9-10; pp. 1062 - 1076
• Main Authors: Zheng, Mingji, Xin, Shaohui, Wang, Qiang, Trébosc, Julien, Xu, Jun, Qi, Guodong, Feng, Ningdong, Lafon, Olivier, Deng, Feng
• Format: Journal Article
• Language: English
• Published: England Wiley 01.09.2021
• Subjects: Chemical Sciences; or physical chemistry; Theoretical and; heteronuclear correlation; spatial proximity; dipolar recoupling; half-integer quadrupolar nuclei; solid-state NMR; dipolar recoupling, half-integer quadrupolar nucle, iheteronuclear correlation, solid-state NMR, spatial proximity
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.5163

Through-space heteronuclear correlation (D-HETCOR) experiments based on heteronuclear multiple-quantum correlation (D-HMQC) and refocused insensitive nuclei enhanced by polarization transfer (D-RINEPT) sequences have been proven to be useful approaches for the detection of the spatial proximity between half-integer quadrupolar nuclei in solids under magic-angle spinning (MAS) conditions. The corresponding pulse sequences employ coherence transfers mediated by heteronuclear dipolar interactions, which are reintroduced under MAS by radiofrequency irradiation of only one of the two correlated nuclei. We investigate herein using numerical simulations of spin dynamics and solid-state NMR experiments on magnesium aluminoborate glass how the choice of the channel to which the heteronuclear dipolar recoupling is applied affects the transfer efficiency of D-HMQC and D-RINEPT sequences between B and Al nuclei. Experimental results show that maximum transfer efficiency is achieved when the recoupling scheme is applied to the channel, for which the spin magnetization is parallel to the B axis in average.