Obtaining high-fidelity powder spectra in anisotropic media: Phase-cycled Hahn echo spectroscopy

摘要: Abstract In the spectroscopy of isolated spin-1 nuclei in anisotropic media, spectral distortion resulting from inability to record initial part free-induction decay was eliminated by using quadrupolar echo technique. Wideline spin - 1 2 is subject same problems associated with finite receiver recovery time as spectroscopy; however, these have been generally ignored past. Through use a very simple and well-known pulse sequence (90°-τ-180°) chemical shift interaction, among others, can be refocused generate so-called Hahn echo. If magnetic dipolar interactions like fluctuating other may neglected, then refocusing magnetization will complete an undistorted powder spectrum obtained Fourier transforming signal starting at peak The practical aspects implementing technique are discussed. A phase-cycling scheme proposed prevent due misset lengths. effects lengths investigated, theoretical single factors demonstrated differ those which were determined for spectroscopy. Experimental verification some predictions provided.