IR Spectroscopy: Identifying Functional Groups with IR Wavenumbers and Peak Descriptions, Lecture notes of Organic Chemistry

Download IR Spectroscopy: Identifying Functional Groups with IR Wavenumbers and Peak Descriptions and more Lecture notes Organic Chemistry in PDF only on Docsity! Summary of IR values wavenumber functional group description 3500-3300 alcohol, COH or amine, CNR2 alcohol is strong, broad amine is usually weak/medium, broad, 2 peaks = 1o amine (RNH2), 1 peak = 2o amine (RR’NH) 3400-2400 acid, COOH very broad, also will have C=O at ~ 1700 3300 alkyne (terminal) sharp, /C-H stretch, also will have 2150 peak 3050 alkene or aromatic =C-H stretch, usually weak 2950 alkane -C-H stretch, usually weak 2750 aldehyde, CHO =C-H stretch, also -1700 peaks 2250 nitrile C/N stretch, medium to strong 2150 alkyne C/C stretch, usually weak 1810, 1760 anhydride, (CO)2O C=O stretch, -30 if conj. 1800 acid chloride, COCl C=O stretch, -30 if conj. 1735 ester, COOR C=O str, -25 if conj at C=O, +30 if conj at O 1725 aldehyde, CHO C=O str, -30 if conj., also 2750 peak 1715 ketone, CO C=O str, -30 if conj., no 2750 peak 1710 acid, COOH C=O str, -30 if conj., also v. broad 3400-2400 -OH 1690 amide, CONR2 C=O str , -30 if conj., also 3300 peak unless 3E 1650 alkene C=C stretch 1250 alkane C-C stretch 1220 O-Aryl O-C str, confirmatory only 1150 O-tert-C, 3o (RR’R”C-O) O-C str, confirmatory only 1100 O-sec-C, 2o (RR’HC-O) O-C str, confirmatory only 1050 O-prim-C, 1o (RH2C-O) O-C str, confirmatory only 990, 910 mono alkene, RCH=CH2 =C-H bend, usually strong, two peaks 970-960 trans-RCH=CHR =C-H bend, usually strong 900 1,1-disubst. alkene, R2C=CH2 =C-H bend, usually strong 880, 780, 690 meta-disubst. Ar ring =C-H bend, three peaks ~825±25 para-disubst. Ar ring =C-H bend, one peak ~750±25 ortho-disubst. Ar ring =C-H bend, one peak ~700 cis-RCH=CHR =C-H bend, weak to medium, position varies 700, 690 mono-subst. Ar ring =C-H bend, two peaks INFRARED ABSORPTION FREQUENCIES OF COMMON FUNCTIONAL GROUPS 4000ce" 3500 3000 oe 16001400 ahr ctobek : gue, i Tha ee TTT | Sar Ul : Trey LEE assect| | |") 4 rl ETHERS ae tees AXCOHOLS. lan : Rrotoneicataeds — Se Bima’ aLeONOLS. — O44'or Se a note: ‘Taco emcomies RV ele iS 5 122 me] Ue (oni urinare! aban mee, OWALENCT NITE irl 1900 800 250p 275 es 300 325 350315400 45 50 TO 7S 80 SO WON 12 IS AIS 600