A NEW NMR METHOD FOR MEASURING THE ROTATIONAL CORRELATION TIME OF MOLECULES IN THE LIQUID-STATE

A method is described for the measurement of the steady-state nuclear magnetization under strong off-resonance RF irradiation as a function of the angle between the external field and the effective field in the rotating frame. For purely dipolar relaxation between homonuclear spi ns under isotropic Brownian molecular rotation, its variation with the angle yields the value of the correlation time. This determination ca n be made locally. A departure from the theoretical shape reveals the existence of complex motions or complex relaxation mechanisms. An expe rimental illustration of the theory is presented.