TY - JOUR

T1 - Frequency offset refocused PISEMA-type sequences

AU - Dvinskikh, Sergey V.

AU - Sandström, Dick

PY - 2005/7/1

Y1 - 2005/7/1

N2 - The popular PISEMA experiment is highly sensitive to the 1H chemical shift dispersion and the choice of the 1H carrier frequency. This is due to the off-resonance 1H irradiation in the FSLG-CP sequence employed during the dipolar evolution period. In the modified approach described in this work, the interfering frequency offset terms are suppressed. In the new pulse schemes, conventional FSLG-CP is intercalated with 180° pulses applied simultaneously to both frequency channels, and with phases set orthogonal to those of the spin-lock fields. The technique is demonstrated on a nematic liquid-crystalline sample. Extensions to amplitude-modulated FSLG-CP recoupling under MAS are also presented.

AB - The popular PISEMA experiment is highly sensitive to the 1H chemical shift dispersion and the choice of the 1H carrier frequency. This is due to the off-resonance 1H irradiation in the FSLG-CP sequence employed during the dipolar evolution period. In the modified approach described in this work, the interfering frequency offset terms are suppressed. In the new pulse schemes, conventional FSLG-CP is intercalated with 180° pulses applied simultaneously to both frequency channels, and with phases set orthogonal to those of the spin-lock fields. The technique is demonstrated on a nematic liquid-crystalline sample. Extensions to amplitude-modulated FSLG-CP recoupling under MAS are also presented.

KW - Cross-polarization

KW - Dipolar couplings

KW - MAS

KW - PISEMA

KW - Separated local field spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=19944387677&partnerID=8YFLogxK

U2 - 10.1016/j.jmr.2005.03.016

DO - 10.1016/j.jmr.2005.03.016

M3 - Article

C2 - 15949754

AN - SCOPUS:19944387677

VL - 175

SP - 163

EP - 169

JO - Journal of Magnetic Resonance - Series A

JF - Journal of Magnetic Resonance - Series A

SN - 1090-7807

IS - 1

ER -