Article ID Journal Published Year Pages File Type
5407497 Journal of Magnetic Resonance 2007 8 Pages PDF
Abstract
When adiabatic fast passage is used to flip nuclear spins, sites with different chemical shifts are inverted at different times, causing refocusing errors. By mapping the phase evolution diagrams, we show that these effects can be accurately compensated with matched pairs of adiabatic pulses, either opposed or in the same sense, depending on the application. Applied to well-known heteronuclear polarization transfer experiments such as INEPT and HSQC, the requisite evolution of J-vectors is achieved irrespective of chemical shift or the duration of the adiabatic sweeps. By replacing conventional 180° pulses, these new adiabatic sequences offer an order of magnitude improvement in effective bandwidth for the X-spins. Alternatively the experiments can be carried out with significantly reduced radiofrequency power. One- and two-dimensional spectra of 13C in 13-cis-retinal at 600 MHz have been used to demonstrate these advantages.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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