@article {431,
	title = {Second-order recoupling of chemical-shielding and dipolar-coupling tensors under spin decoupling in solid-state NMR},
	journal = {Journal of Chemical Physics},
	volume = {105},
	year = {1996},
	note = {J Chem PhysVd768Times Cited:55Cited References Count:53},
	month = {Sep 1},
	pages = {3387-3397},
	abstract = {<p>The source of the residual line broadening in continuous-wave (cw) decoupled spectra under magic-angle sample spinning conditions is reexamined. It is shown that an important contribution to the line broadening comes from a second-order recoupling of the heteronuclear dipolar-coupling tensor and the chemical-shielding tensor of the irradiated spin. Such an interference between the two tensors leads to a sum of a zeroth-rank, a second-rank, and a fourth-rank tensor component in the Hamiltonian. The zeroth-rank and the fourth-rank tensor components are not averaged out under magic-angle sample spinning (MAS) conditions, requiring the use of higher-order averaging such as double rotation (DOR) for obtaining narrow lines. This broadening is distinctly different from off-resonance decoupling effects which transform as a second-rank tensor and can be averaged out by MAS. The properties of this second-order recoupling as a source of structural information are explored, and the conditions for removing the broadening in systems with weak homonuclear dipolar-coupling networks are discussed. (C) 1996 American Institute of Physics.</p>
},
	keywords = {waltz-16},
	isbn = {0021-9606},
	doi = {Doi 10.1063/1.472224},
	url = {<Go to ISI>://WOS:A1996VD76800005},
	author = {Ernst, M. and Bush, S. and Kolbert, A. C. and Pines, A.}
}
