MEASUREMENT OF C-13-N-15 COUPLING BY DIPOLAR-ROTATIONAL SPIN-ECHO NMR

A sign reversal of the 13Cz.sbnd;15N heteronuclear dipolar interaction after the first of two rotor periods in a dipolar-rotational spin-echo experiment produces a 13C15N dipolar-modulation period equal to twice that of the rotor. This doubling results in twice as many sidebands in the dipolar powder pattern as in conventional experiments. Some of the sidebands have negative intensities. The increases in the number of sidebands and in the dynamic range of sideband intensities aid in the measurement of weak 13C15N dipolar couplings in solids. © 1990.