红外常见官能团的特征吸收频率.doc

BondType of bondSpecific type of bondAbsorption peakAppearanceCHalkylmethyl1260 cm1strong1380 cm1weak2870 cm1medium to strong2960 cm1medium to strongmethylene1470 cm1strong2850 cm1medium to strong2925 cm1medium to strongmethine2890 cm1weakvinylCCH2900 cm1strong2975 cm1medium3080 cm1mediumCCH3020 cm1mediummonosubstituted alkenes900 cm1strong990 cm1strongcis-disubstituted alkenes670700 cm1strongtrans-disubstituted alkenes965 cm1strongtrisubstituted alkenes800840 cm1strong to mediumaromaticbenzene/sub. benzene3070 cm1weakmonosubstituted benzene700750 cm1strong690710 cm1strongortho-disub. benzene750 cm1strongmeta-disub. benzene750800 cm1strong860900 cm1strongpara-disub. benzene800860 cm1strongalkynesany3300 cm1mediumaldehydesany2720 cm1medium2820 cm1CCacyclic CCmonosub. alkenes1645 cm1medium1,1-disub. alkenes1655 cm1mediumcis-1,2-disub. alkenes1660 cm1mediumtrans-1,2-disub. alkenes1675 cm1mediumtrisub., tetrasub. alkenes1670 cm1weakconjugated CCdienes1600 cm1strong1650 cm1strongwith benzene ring1625 cm1strongwith CO1600 cm1strongCC (both sp2)any16401680 cm1mediumaromatic CCany1450 cm1weak to strong (usually 3 or 4)1500 cm11580 cm11600 cm1CCterminal alkynes21002140 cm1weakdisubst. alkynes21902260 cm1very weak (often indisinguishable)COaldehyde/ketonesaturated aliph./cyclic 6-membered1720 cm1,-unsaturated1685 cm1aromatic ketones1685 cm1cyclic 5-membered1750 cm1cyclic 4-membered1775 cm1aldehydes1725 cm1influence of conjugation (as with ketones)carboxylic acids/derivatessaturated carboxylic acids1710 cm1unsat./aromatic carb. acids16801690 cm1esters and lactones1735 cm1influenced by conjugation and ring size (as with ketones)anhydrides1760 cm11820 cm1acyl halides1800 cm1amides1650 cm1associated amidescarboxylates (salts)15501610 cm1amino acid zwitterions15501610 cm1OHalcohols, phenolslow concentration36103670 cm1high concentration32003400 cm1broadcarboxylic acidslow concentration35003560 cm1high concentration3000 cm1broadNHprimary aminesany34003500 cm1strong15601640 cm1strongsecondary aminesany3000 cm1weak to mediumammonium ionsany24003200 cm1multiple broad peaksCOalcoholsprimary10401060 cm1strong, broadsecondary1100 cm1strongtertiary11501200 cm1mediumphenolsany1200 cm1ethersaliphatic1120 cm1aromatic12201260 cm1carboxylic acidsany12501300 cm1estersany11001300 cm1two bands (distinct from ketones, which do not possess a CO bond)CNaliphatic aminesany10201220 cm1often overlappedCNany16151700 cm1similar conjugation effects to COCN (nitriles)unconjugated2250 cm1mediumconjugated2230 cm1mediumRNC (isocyanides)any21652110 cm1RNCSany21401990 cm1CXfluoroalkanesordinary10001100 cm1trifluromethyl11001200 cm1two strong, broad bandschloroalkanesany540760 cm1weak to mediumbromoalkanesany500600 cm1medium