13.19 Infrared Spectroscopy,Gives information about the functional groups in a molecule,region of infrared that is most useful lies between 2.5-16 mm (4000-625 cm-1) depends on transitions between vibrational energy states stretching bending,Infrared Spectroscopy,Stretching Vibrations of a CH2 Group,Symmetric,Antisymmetric,Bending Vibrations of a CH2 Group,In plane,In plane,Bending Vibrations of a CH2 Group,Out of plane,Out of plane,Francis A. Carey, Organic Chemistry, Fourth Edition. Copyright 2000 The McGraw-Hill Companies, Inc. All rights reserved.,Wave number, cm-1,Figure 13.26: Infrared Spectrum of Hexane,CH3CH2CH2CH2CH2CH3,CH stretching,bending,bending,bending,Francis A. Carey, Organic Chemistry, Fourth Edition. Copyright 2000 The McGraw-Hill Companies, Inc. All rights reserved.,Wave number, cm-1,Figure 13.27: Infrared Spectrum of 1-Hexene,H2C=CHCH2CH2CH2CH3,HC,C=CH,C=C,H2C=C,Structural unit Frequency, cm-1 Stretching vibrations (single bonds) sp CH 3310-3320 sp2 CH 3000-3100 sp3 CH 2850-2950 sp2 CO 1200 sp3 CO 1025-1200,Table 13.4 (p 519) Infrared Absorption Frequencies,Structural unit Frequency, cm-1 Stretching vibrations (multiple bonds),Table 13.4 (p 519) Infrared Absorption Frequencies,1620-1680,2100-2200,2240-2280,Structural unit Frequency, cm-1 Stretching vibrations (carbonyl groups) Aldehydes and ketones 1710-1750 Carboxylic acids 1700-1725 Acid anhydrides 1800-1850 and 1740-1790 Esters 1730-1750 Amides 1680-1700,Table 13.4 (p 519) Infrared Absorption Frequencies,Structural unit Frequency, cm-1 Bending vibrations of alkenes,Table 13.4 (p 519) Infrared Absorption Frequencies,910-990,890,665-730,960-980,790-840,Structural unit Frequency, cm-1 Bending vibrations of derivatives of benzene Monosubstituted 730-770 and 690-710 Ortho-disubstituted 735-770 Meta-disubstituted 750-810 and 680-730 Para-disubstituted 790-840,Table 13.4 (p 519) Infrared Absorption Frequencies,Francis A. Carey, Organic Chemistry, Fourth Edition. Copyright 2000 The McGraw-Hill Companies, Inc. All rights reserved.,Wave number, cm-1,Figure 13.28: Infrared Spectrum of tert-butylbenzene,Monsubstituted benzene,C6H5C(CH3)3,Structural unit Frequency, cm-1 Stretching vibrations (single bonds) OH (alcohols) 3200-3600 OH (carboxylic acids) 3000-3100 NH 3350-3500,Table 13.4 (p 519) Infrared Absorption Frequencies,Francis A. Carey, Organic Chemistry, Fourth Edition. Copyright 2000 The McGraw-Hill Companies, Inc. All rights reserved.,Wave number, cm-1,Figure 13.29: Infrared Spectrum of 2-Hexanol,Francis A. Carey, Organic Chemistry, Fourth Edition. Copyright 2000 The McGraw-Hill Companies, Inc. All rights reserved.,Wave number, cm-1,Figure 13.29: Infrared Spectrum of 2-Hexanone,