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Spectroscopy Data and Information : Infrared (IR) Spectroscopy

Where to find IR, NMR, and other spectral data online and in our print collection

Books with IR Spectral Data

Characteristic IR Band Positions

Group Frequency Range (cm-1)
OH stretching vibrations
Free OH 3610-3645 (sharp)
Intramolecular H bonds 3450-3600 (sharp)
Intermolecular H Bonds 3200-3550 (broad)
Chelate Compounds 2500-3200 (very broad)
NH Stretching vibrations
Free NH 3300-3500
H bonded NH 3070-3350
CH Stretching vibrations
=-C-H 3280-3340
=C-H 3000-3100
C-CH3 2862-2882, 2652-2972
O-CH3 2815-2832
N-CH3 (aromatic) 2810-2820
N-CH3 (aliphatic) 2780-2805
CH2 2843-2863,2916-2936
CH 2880-2900
SH Stretching Vibrations
Free SH 2550-2600
C=-N Stretching Vibrations
Nonconjugated 2240-2260
Conjugated 2215-2240
C=-C Stretching Vibrations
C=-CH (terminal) 2100-2140
C-C=-C-C 2190-2260
C-C=-C-C=-CH 2040-2200
C=O Stretching Vibrations
Nonconjugated 1700-1900
Conjugated 1590-1750
Amides ~1650
C=C Stretching Vibrations
Nonconjugated 1620-1680
Conjugated 1585-1625
CH Bending Vibrations
CH2 1405-1465
CH3 1355-1395, 1430-1470
C-O-C Vibrations in Esters
Formates ~1175
Acetates ~1240, 1010-1040
Benzoates ~1275
C-OH Stretching Vibrations
Secondary Cyclic Alcohols 990-1060

CH out-of-plane bending vibrations in substituted ethylenic systems

-CH=CH2 905-915, 985-995
-CH=CH-(cis) 650-750
-CH=CH-(trans) 960-970
C=CH2 885-895

Table from ALS website
 

Introduction to IR Spectroscopy

Websites and Databases with IR Data