Better 180 Degree Pulses

Many pulse sequences use 180 degree pulses. Standard hard pulses are not perfect at inverting all of the lines in a spectrum with a wide spectra width. In such cases a better choice may be a shaped adiabatic pulse. A comparison is shown below for the ¹³C spectrum of ethyl acetate. Each spectrum was acquired with the same number of scans. The trace on the left was acquired with a hard 180 degree pulse and the spectrum on the right was acquired with the CRP60comp.4 pulse from the Bruker pulse shape library. Note the better performance resulting in improved nulls.