on the right ring have oppositely signed B H for ES2, resulting in partial quenching of the NSCD of ES2 in the combined spectra. The two summed spectra of the left-ring carbons both exhibit a positive/negative spectral shape, and the right-ring combined spectra share a strong positive peak at higher frequencies, thus making the carbons on the two rings distinguishable. This also applied to the hydrogens, where the three right-ring spectra have the same positive/negative feature and the left-ring pairs have negative/pseudo-A spectral shape.