Studies of minute quantities of natural abundance molecules using 2D Heteronuclear correlation spectroscopy under 100 kHz MAS: HMQC approach

Cross-polarization (CP) is widely used for ¹H/¹³C magnetization transfer in solid-state NMR. However, J-based transfer can only be used when ¹H T₂ relaxation time is much longer than 1/4J. This can be achieved for some molecules at very fast MAS > 100 kHz. Because of the very high magnetization transfer efficiency (100% if relaxation is neglected), ¹H/¹³C HMQC can be quickly recorded even in ¹³C natural abundance.

¹H/¹³C HMQC pulse sequence

¹H/¹³C HMQC spectra of organically functionalized mesoporous
silica nanoparticles in natural abundance

Reference

Y. Nishiyama, T. Kobayashi, M. Malon, D. Singappuli-Arachchige, I.I. Slowing, M. Pruski, Solid State Nucl. Magn. Reson. 66-67 (2015) 56-61.