Chemical Shifts in 1H NMR for Organic Chemistry

California State Polytechnic University Pomona Dr Laurie S Starkey Organic Chemistry Lab CHM 318L 1H NMR Chemical Shifts 11 10 9 8 7 6 5 4 3 2 1 0 R H O H R2C CR H ROCH3 CH3 R CH3 O RH CH3 C H N H O H R NH2 O NH2 RNH2 R OH O OH ROH δ ppm Type of CH δ ppm Description of Proton 09 alkyl methyl 13 alkyl methylene 152 alkyl methine 18 allylic C is next to a pi bond 223 α to carbonyl C is next to CO 23 benzylic C is next to Ph 25 alkynyl 23 α to nitrogen C is attached to N 24 α to halogen C is attached to Cl Br I 38 α to oxygen C is attached to O 553 vinylic H is attached to alkene C 73 aromatic H is on phenyl ring 97 aldehyde H is on CO R CH3 R CH2 R R3C H R2C CR H Ar CH3 RC C H R2N CH3 R CH2 X RO CH3 Ar H R C H O R C CH3 O CH3 Protons on Carbon Type of H δ ppm Description ROH ArOH R C OH O RNH2 R C NHR O ArNH2 R CH2 F 45 α to fluorine C is attached to F 055 alcohol 47 phenol 1013 carb acid 055 amine 35 aniline 59 amide Protons on OxygenNitrogen Protons on N or O typically have wide ranges of expected chemical shifts the actual δ value depends on the solvent used the concentration temperature etc Because these protons are acidic and therefore exchangeable they may be broad peaks and usually do not couple with neighboring protons typically they are broad singlets If a protic deuterated solvent is used eg D2O or CD3OD then the NH and OH protons will exchange with the deuterium and the peaks will shrink or disappear entirely since D 2H does not show up in the 1H NMR spectrum R alkyl group Ar aromatic ring such as phenyl Ph Note aldehyde CHO proton usually does not couple with neighboring Hs so appears as a singlet