COMPOZER-based longitudinal cross-polarization via dipolar coupling under MAS

Takayuki Kamihara; Miwa Murakami; Yasuto Noda; Kazuyuki Takeda; K Takegoshi

doi:10.1016/j.jmr.2014.06.003

COMPOZER-based longitudinal cross-polarization via dipolar coupling under MAS

J Magn Reson. 2014 Aug:245:94-7. doi: 10.1016/j.jmr.2014.06.003. Epub 2014 Jun 24.

Authors

Takayuki Kamihara¹, Miwa Murakami², Yasuto Noda¹, Kazuyuki Takeda¹, K Takegoshi³

Affiliations

¹ Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
² National Institute for Materials Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan.
³ Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan. Electronic address: takeyan@kuchem.kyoto-u.ac.jp.

PMID: 25023565
DOI: 10.1016/j.jmr.2014.06.003

Abstract

We propose a cross polarization (CP) sequence effective under magic-angle spinning (MAS) which is tolerant to RF field inhomogeneity and Hartmann-Hahn mismatch. Its key feature is that spin locking is not used, as CP occurs among the longitudinal (Z) magnetizations modulated by the combination of two pulses with the opposite phases. We show that, by changing the phases of the pulse pairs synchronized with MAS, the flip-flop term of the dipolar interaction is restored under MAS.

Keywords: Cross polarization; Flip–flop exchange; Magic-angle spinning.