Dipolar-coupling-mediated total correlation spectroscopy in solid-state 13C NMR: selection of individual 13C-13C dipolar interactions.
Herein is described a useful approach in solid-state NMR, for selecting homonuclear (13)C-(13)C spin pairs in a multiple-(13)C homonuclear dipolar coupled spin system. This method builds upon the zero-quantum (ZQ) dipolar recoupling method introduced by Levitt and coworkers (Marin-Montesinos et al., 2006) by extending the originally introduced one-dimensional (1D) experiment into a two-dimensional (2D) method with selective irradiation scheme, while moving the (13)C-(13)C mixing scheme from the transverse to the longitudinal mode, together with a dramatic improvement in the proton decoupling efficiency. Selective spin-pair recoupling experiments incorporating Gaussian and cosine-modulated Gaussian pulses for inverting specific spins were performed, demonstrating the ability to detect informative, simplified/individualized, long-range (13)C-(13)C homonuclear dipolar coupling interactions more accurately by removing less informative, stronger, short-range (13)C-(13)C interactions from 2D correlation spectra. The capability of this new approach was demonstrated experimentally on uniformly (13)C-labeled Glutamine and a tripeptide sample, GAL.
Spano
Justin
J
Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, USA.
Wi
Sungsool
S
D000465:Algorithms; D002247:Carbon Isotopes / Q000737:chemistry*; D005973:Glutamine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
D002247:Carbon Isotopes; D005973:Glutamine