Low rf power high resolution H-1-C-13-N-14 separated local field spectroscopy in lyotropic mesophases

• Published in: Journal of magnetic resonance (1997) Vol. 223; p. 73
• Main Authors: Kharkov, Boris B., Chizhik, V. I., Dvinskikh, Sergey V.
• Format: Journal Article
• Language: English
• Published: 01.10.2012
• Subjects: Heteronuclear dipolar coupling; Liquid crystal; PDLF; Separated local field spectroscopy
• ISSN: 1096-0856; 1090-7807
• DOI: 10.1016/j.jmr.2012.07.012

Efficiency of the proton detected (encoded) H-1-C-13-N-14 local field spectroscopy technique at low radiofrequency power is examined when applied to concentrated ionic lyotropic mesophases exhibiting heteronuclear and homonuclear dipolar couplings in kHz range. We demonstrate that highly resolved heteronuclear dipolar spectra can be obtained with limited radiofrequency power corresponding to decoupling B-1 field of 20 kHz and with superior spectral resolution and sensitivity provided by standard solution state probes. To maintain sufficiently large spectral window in indirect dimension, power level alternation scheme for homonuclear decoupling was introduced. In anisotropic mesophases of an ionic surfactant, pair-wise coupling constants in the three-spin system H-1-C-13-N-14 were accurately determined. Relative signs of heteronuclear dipolar couplings to nitrogen were obtained employing frequency selective decoupling.