Solid-state heteronuclear correlation

In order to confirm this view, we performed the solid-state heteronuclear correlation experiment, which can measure spin diffusion more accurately. With... 

S. Cadars, R. Guegan, M. Garaga, X. Bourrat, L. Le Forectier, F. Fayon, T. Vu Huynh, T. AUier, Z. Nour, D. Massiot, Effects of the orientation of the Na- Si dipolarvector on the dipolar mediated heteronuclear solid state NMR correlation spectrum of crys-taUine sodium sUicates, Chem. Mater. 24 (2012) 4376-4389. 

Fyfe, C.A., Zhang, Y., and Aroca, P. 1992. An alternative preparation of organofunctionalized silica gels and their characterization by twodimensional high-resolution solid-state heteronuclear NMR correlation spectroscopy, y. Am. Chem. Soc. 114 3252-3255. 

Recently two-dimensional solid-state heteronuclear chemical shift correlation experiments involving magic angle sample spinning (MASS) have been described. This technique results in an increase in the resolution of solid-state proton spectra by a factor of 5-10. Solid-state NMR spectroscopy has hitherto been confined to C-NMR spectra since the residual line widths in the spectra of solid samples are around 2 ppm, so that only four or five nonequivalent protons can be distinguished in the normal proton spectral region of 10-15 ppm. The increase in resolution attained by the 2D solid-state heteronuclear COSY experiment should promote further studies of the H-NMR spectra of solid samples. 

The development and application of multidimensional solid state homo- and heteronuclear correlation (HETCOR) NMR techniques have lead to an increasingly important role in structure solution of zeolitic materials and have had many practical applications in the detailed structural characterization of completely siliceous zeolites[6,7] and AlPOs.[8-ll] However, HETCOR NMR is not readily applicable to aluminosilicates... 

A useful approach to solve these problems is solid-state two-dimensional (2D) C H heteronuclear correlation (HETCOR) spectroscopy. 

Further possibilities are offered by various two-dimensional NMR methods. For example, heteronuclear solid-state correlation spectroscopy (27) is capable of correlating the spectra of abundant and dilute spins in solids, simplifying spectral assignment and permitting determination of shielding tensors. Futhermore, spin diffusion among abundant spins can be directly observed by this method. 

One of the common 2D SS NMR approaches employed for investigation of phosphoro-organic and bio-organic samples is based on high-resolution heteronuclear correlations (EIETCOR). In solution-state NMR, this technique is the basic method that allows assignment of proton and phosphorus to the molecular structure. In the solid state, the assignment is more complex because of the very... 

Gougeon, R.D., Reinholdt, M., Delmotte, L., Miehe-Brendle, J., Chezeau, J.M., Le Dred, R., Mar-chal, R., Jeandet, P. (2002). Direct observation of polylysine side-chain interaction with smectites interlayer surfaces through H- A1 heteronuclear correlation NMR spectroscopy. Langmuir, the American Chemical Society Journal of Surfaces and Colloids, 18, 3396-3398 Gougeon, R.D., Soulard, M., Reinholdt, M., Miehe-Brendle, J., Chezeau, J.M., Le Dred, R., Mar-chal, R., Jeandet, P. (2003). Polypeptide adsorption onto a synthetic montmoriUonite A combined solid-state NMR, X-ray diffraction, thermal analysis and N2 adsorption study. Eur. J. Inorg. Chem., 2003, 1366-1372... 

General symmetry principles for rotor-synchronized pulse sequences in MAS solid-state NMR have been presented. The synunetry theory has been extended to the case of generalized Hartmann-Hahn sequences, in which rotor-synchronized r.f. irradiation is applied simultaneously to two isotopic spin species. The symmetry theory has been used to design pulse sequences which implement heteronuclear dipolar recoupling at the same time as decoupling homonuclear spin-spin interactions, and which also suppress CSAs. Experimental demonstrations of heteronuclear 2D correlation spectroscopy, heteronuclear MQ spectroscopy, and the estimation of intemuclear dipolar couplings have been given. 

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