Chemical applications of high-resolution 13 C n.m.r. spectra for solids

Abstract
13 C n.m.r. experiments are described that use the dipolar decoupling, cross-polarization and magic angle rotation techniques with a home-built spectrometer system. The subsidiary experimental methods of ( a ) spin-echo Fourier transform, ( b ) magnetization flip-back, ( c ) non-quaternary suppression and ( d ) single-pulse excitation are mentioned, and the equipment is briefly described. Applications of the methods are presented that have involved organic compounds, polymeric materials and inorganic systems. Discussion centres on special features of solid state spectra such as ( a ) multiplicity of crystallographic sites, ( b ) chemical shift and bandwidth differences from solution state spectra, and ( c ) effects of coupling to heteronuclei. Emphasis is placed on the value of the experiments for structural chemistry, as in cases of tautomerism, polymorphism and hindered intramolecular motion.