Cross polarization and magic angle

The methods of high power decoupling, cross-polarization and magic angle spinning produce useful spectra from intractable polymers. In a rather rigid material... 

Structure identification, quantifying relative cage occupancies. 1II NMR has been used for ethane, propane, and isobutane hydrates (Davidson et al., 1977 Garg et al., 1977), while 2H, 19F, 31P, and 77 Se NMR have been used for several si guests (Collins et al., 1990). 13C cross-polarization and magic angle spinning (MAS) NMR techniques have been applied to study hydrates of carbon dioxide, methane, and propane (Ripmeester and Ratcliffe, 1988, 1999 Wilson et al., 2002 Kini et al., 2004). 

We have been interested in the nature of cooperative motions in polymers for some time and have used carbon-13 nuclear magnetic resonance for examining main-chain motions in solids (22-27). Carbon-13 nmr with cross-polarization and magic-angle... 

Figure 1. Cross-polarization and magic-angle spinning C-NMR spectra of PVC-TCP systems. The 15.08 MHz spectra were obtained with 1 msec contact time and 1800 Hz spinning speed.

Preston, C.,Trofymow, J., Sayer, B., and Niu, J. (1997). 13C nuclear magnetic resonance spectroscopy with cross-polarization and magic-angle spinning investigation of the proximate-analysis fractions used to assess litter quality in decomposition studies. Can. J. Bot. 75, 1601-1613. 

Finally, 13C-NMR with cross-polarization and magic angle spinning (13C-CP/MAS) has been used to examine changes in the mesomorphic states of phospholipids at various temperatures in the absence and presence of the two drugs. Three effects were followed ... 

The direct determination of the aromaticity in coal was first reported by VanderHardt and Retcofsky (9) using nonspinning carbon-13 NMR techniques. More refined studies using a combination of cross-polarization and magic-angle spinning (CP/MAS) has been used to examine the aromaticity in a number of different coals (10, ll). 

Haw JF, Maciel GE, Schroeder HA (1984) Carbon-13 nuclear magnetic resonance spectrometric study of wood and wood pulping with cross polarization and magic-angle spinning Anal Chem 56 1323-1329... 

NMR, especially cross-polarization and magic-angle spinning NMR (CP/MAS NMR), is also a powerful tool for studying the molecular conformations of the TAGs in a crystalline state, because CP/MAS NMR spectra give detailed information about the local environment and mobility of specific carbon sites (29-33). 

Palmer, A. R. and Maciel, G. E. (1982). Relaxation behavior in the carbon-13 nuclear magnetic resonance spectrometric analysis of kerogen with cross-polarization and magic-angle spinning. Anal. Chem. 54, 2194-2198. 

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