Spin decoupling schemes

Note, the term Z(q, a>) in the dynamical spin susceptibility occurs in the higher order decoupling scheme for the Green s function. It originates from the spin fluctuations in the singlet pd-band and lower Hubbard (copper) band, which is in hole-doped cuprates is completely filled. 

FIG. 28. Pulsing schemes for controlling the NOE. (a) With retention of the NOE and no spin decoupling, (b) Decoupled with NOE suppressed. From ref. 248. 

The third new compound candidissiol (41) may arised by the possible rearrangement of aethiopinone (42) as shown in Scheme 1. The structure of 41 was determined from ID and 2D NMR techniques including H- H and H- C COSY as well as NOE and spin decoupling experiments. The H NMR... 

Shaka AT, Lee CJ, Pines A (1988) Iterative schemes for bilinear operators — application to spin decoupling. J Magn Reson 77 274—293... 

It has been shown that a direct spectral optimisation scheme can be implemented to obtain improved heteronuclear dipolar decoupling schemes for solid state MAS NMR experiments. The resulting schemes, which turn out to have a particularly simple form, are shown to be applicable over the whole range of commercially available spinning speeds (from 5 to 35 kHz), and are shown to improve on the performance of the best existing sequences. 

HMQC). The initial part of the sequence, labeled BIRD, is a pulse scheme for removing from the spectrum the H resonances of protons attached to nuclei. The filled symbols denote 90° pulses and the open symbols denote 180° pulses, x, y, and 0 refer to RF pulse phases. The delay A is set to 1/(2 x u/ch)- GARP denotes a pulse method of spin decoupling all nuclei. 

Z.H. Gan, P.K. Madhu, J.-P. Amoureux, J. Trebosc, O. Lafon, A tunable homonuclear dipolar decoupling scheme for high-resolution proton NMR of sohds from slow to fast magic-angle spinning, Chem. Phys. Lett. 503 (2011) 167—170. 

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