A VERSATILE NMR SPECTROMETER FOR OBSERVING ABUNDANT SPINS IN CONDENSED PHASES

An NMR spectrometer is described which is capable of handling a wide range of experiments on abundant spins in condensed phases under low- and medium-resolution conditions. The control and RF units are interfaced to two separate magnet/probe systems. One is designed for relaxation or wideline experiments at temperatures within 50 K of ambient temperature whereas the other involves a cryogenic probe for studying samples at temperatures down to approximately 20 K. The spectrometer offers versatile pulse programming, flexible data manipulation and sophisticated statistical analysis. It is particularly well suited to observing 1H lineshape and relaxation phenomena in samples which have a spin system that is heterogeneous in terms of molecular mobility, and to the determination of NMR parameters of molecules isolated in inert matrices at cryogenic temperatures. Some representative proton relaxation data are reported for samples of polypropylene. These show that the spectrometer system has adequate reproducibility and sensitivity.