Evaluation of a new broadband decoupling sequence: WALTZ-16. Shaka, A J, Keeler, J., & Freeman, R. Journal of Magnetic Resonance (1969), 53(2):313–340, June, 1983. ISBN: 0022-2364
Evaluation of a new broadband decoupling sequence: WALTZ-16 [link]Paper  doi  abstract   bibtex   
A new scheme for low-power broadband heteronuclear decoupling is described, based on the use of a composite radiofrequency pulse sequence 90??(+X) 180??(-X) 270??(+X), incorporated into a repeated cycle or supercycle. Its principal attribute is that the residual splittings on the observed resonances (usually carbon-13) are very small (less than 0.1 Hz) for a wide range of decoupler offsets (approximately -B2 \textless??B \textless+B2). Existing theories of broadband decoupling are used to calculate the effects of various possible instrumental imperfections on decoupling performance. It is concluded that spatial inhomogeneity of the B2 field has a perceptible influence near the extremes of the decoupler bandwidth. Only 180?? shifts of the radiofrequency phase are used, and the performance is remarkably insensitive to the exact setting of this phase shift. Any decoupler which employs a systematic modulation scheme runs the risk of introducing "cycling sidebands" into the observed spectrum; it is demonstrated that with the proposed sequence these sidebands are very weak, particularly when the decoupling cycle and the signal acquisition processes are not synchronized. As an illustration, the broadband-decoupled carbon-13 spectrum of an aniline derivative is recorded showing natural-abundance carbon-13 satellite signals but no appreciable cycling sidebands. The circuit for a practical implementation of this decoupling sequence is described. ?? 1983.
@article{The1983,
	title = {Evaluation of a new broadband decoupling sequence: {WALTZ}-16},
	volume = {53},
	issn = {00222364},
	url = {http://linkinghub.elsevier.com/retrieve/pii/0022236483900355},
	doi = {10.1016/0022-2364(83)90035-5},
	abstract = {A new scheme for low-power broadband heteronuclear decoupling is described, based on the use of a composite radiofrequency pulse sequence 90??(+X) 180??(-X) 270??(+X), incorporated into a repeated cycle or supercycle. Its principal attribute is that the residual splittings on the observed resonances (usually carbon-13) are very small (less than 0.1 Hz) for a wide range of decoupler offsets (approximately -B2 {\textless}??B {\textless}+B2). Existing theories of broadband decoupling are used to calculate the effects of various possible instrumental imperfections on decoupling performance. It is concluded that spatial inhomogeneity of the B2 field has a perceptible influence near the extremes of the decoupler bandwidth. Only 180?? shifts of the radiofrequency phase are used, and the performance is remarkably insensitive to the exact setting of this phase shift. Any decoupler which employs a systematic modulation scheme runs the risk of introducing "cycling sidebands" into the observed spectrum; it is demonstrated that with the proposed sequence these sidebands are very weak, particularly when the decoupling cycle and the signal acquisition processes are not synchronized. As an illustration, the broadband-decoupled carbon-13 spectrum of an aniline derivative is recorded showing natural-abundance carbon-13 satellite signals but no appreciable cycling sidebands. The circuit for a practical implementation of this decoupling sequence is described. ?? 1983.},
	number = {2},
	journal = {Journal of Magnetic Resonance (1969)},
	author = {Shaka, A J and Keeler, James and Freeman, Ray},
	month = jun,
	year = {1983},
	note = {ISBN: 0022-2364},
	keywords = {\#nosource},
	pages = {313--340},
}

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