The sp² hybridized carbon atoms of alkenes and benzene rings are and absorb . ¹³ c nmr absorptions typically occur over the range of ppm. a triplet is an nmr single that is split into three peaks having a relative area of , caused by nearby nonequivalent protons. an upfield shift means a signal is shifted to the in the spectrum to chemical shifts. electronegative elements like halogens, nitrogen, and oxygen shift absorptions . the proton’s is determined by shielding and deshielding effects. a doublet is an nmr signal that is split into two peaks of area, caused by nearby nonequivalent proton. a downfield shift means a signal is shifted to the in the spectrum to chemical shifts on the δ scale.