Two-dimensional NMR measurements of heteronuclear dipolar powder spectra using the chemical-shift-anisotropy recovery technique

A novel and simple method for measuring heteronuclear dipolar spectra under magic-angle sample spinning is described; the present method utilizes a chemical-shift-anisotropy recovery technique exploited by Tycko, Dabbagh and Mirau in a two-dimensional NMR experimental scheme. The 13C–15N dipolar powder spectrum was obtained to give a internuclear distance for a doubly labeled l-alanine. The present method will be extended to observe a heteronuclear dipolar interaction between 13C and quadrupolar nuclei having integer spins such as 2H or 14N.