Cross-polarization with radio-frequency field phase and amplitude modulation under magic-angle spinning conditions
2006 (English)In: Journal of Experimental and Theoretical Physics, ISSN 1063-7761, E-ISSN 1090-6509, Vol. 102, no 1, 91-101 p.Article in journal (Refereed) Published
Nucleus cross-polarization technique in a rotating frame of reference is analyzed as applied to NMR experiments with sample magic-angle spinning. The concept of simultaneous phase and amplitude modulation is suggested. According to this suggestion, the form of the Hamiltonian of recoupled dipolar interaction remains unchanged if phase inversion is accompanied by inversion of the difference of radio-frequency (RF) field amplitudes. A theoretical treatment is given in terms of the average Hamiltonian theory. The concept is demonstrated experimentally and by numerical analysis for several particular cases. Periodic phase inversion in cross-polarization experiments was shown to have the practically important advantage of suppressing chemical shift interactions and the effect of inaccurate tuning of RF field parameters.
Place, publisher, year, edition, pages
2006. Vol. 102, no 1, 91-101 p.
solid-state nmr, nuclear-magnetic-resonance, heteronuclear dipolar couplings, proton-enhanced nmr, mas nmr, hexaoctyloxy-rufigallol, columnar phases, segmental order, rotating solids, lipid-bilayers
IdentifiersURN: urn:nbn:se:kth:diva-15681DOI: 10.1134/s1063776106010110ISI: 000237594200011OAI: oai:DiVA.org:kth-15681DiVA: diva2:333723
QC 201005252010-08-052010-08-05Bibliographically approved