C-13-C-13 polarization transfer by resonant interference recoupling under magic-angle spinning in solid-state NMR

A novel mechanism for C-13-C-13 polarization transfer under magic angle spi nning (MAS) is presented. By applying a recently proposed C-13-H-1 recoupli ng sequence under MAS, the spin part of the C-13-H-1 dipolar interaction is modulated with a particular frequency so that non-commutable time-dependen t C-13-H-1 and C-13-C-13 dipolar interactions interfere with each other. Th is novel polarization-transfer approach is theoretically explained and expe rimentally demonstrated using [1,3-C-13] L-alanine. (C) 1999 Elsevier Scien ce B.V. All rights reserved.