Special Characteristics of High Resolution Solid-State Spectrometers

10 Special characteristics of high resolution solid-state spectrometers 

As it was shown previously (section 6.5.8), some characteristics of the solid state make the NMR spectra look different for solids than for liquids. In order to obtain high-resolution spectra the following technical features are used. 

Dipolar interactions (leading to coupling patterns between nuclei which are not directly bonded) can be minimized by using high-power decoupling fields. If the decoupling power usually employed for liquids is about 5 W, typically 50 -100 W are required for solids. 

Broadening due to chemical shift anisotropy can be reduced using the magic-angle-spinning (MAS) technique. MAS involves very fast spinning of the 

Relaxation times can he reduced by a technique named cross-polarization (CP), which results in polarization transfer between highly polarizable H-nuclei and the observed nuclei (usually C). 

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