title: COMPOZER-based longitudinal cross-polarization via dipolar coupling under MAS.
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.
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kamihara
authors.affiliation: National Institute for Materials Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Noda
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Takeda
authors.affiliation: 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.
authors.forename: K
authors.initials: K
authors.lastname: Takegoshi
keywords: Cross polarization; Flip–flop exchange; Magic-angle spinning