Using the same approach as in section 7.8.1 on page 159, show that the effect of a spin echo (in a homonuclear system) on the terms 21x2z and 21yz is as follows:

Using the idea that a spin echo is equivalent to evolution of the coupling for time 2Ï„, followed by a 180° pulse, draw up a table similar to that on page 161 for a spin echo, in which the 180° pulse is applied about the y-axis.
Extend both your table and that on page 161 to include in- and anti-phase operators on spin two.

211x12 21y/2