Simplified Summary of IR Stretching Frequencies

3300 alcohol amine, amide alkyne O—H N—H =C—H always broad may be broad, sharp, or broad with spikes always sharp, usually strong 

2200 alkyne nitrile —c=c— — C N Just below 2200 cm just above 2200 cm  

1710 (very strong) carbonyl c=o ketones, aldehydes, acids esters higher, about 1735 cm conjugation lowers frequency amides lower, about 1650 cm  

1660 alkene conjugation lowers frequency aromatic C=C about 1600cm  

Ethers, esters, and alcohols also show C—O stretching between 1000 and 1200 cm.  

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The Infrared Region 515 12-4 Molecular Vibrations 516 12-5 IR-Active and IR-lnactive Vibrations 518 12-6 Measurement of the IR Spectrum 519 12-7 Infrared Spectroscopy of Hydrocarbons 522 12-8 Characteristic Absorptions of Alcohols and Amines 527 12-9 Characteristic Absorptions of Carbonyl Compounds 528 12-10 Characteristic Absorptions of C—N Bonds 533 12-11 Simplified Summary of IR Stretching Frequencies 535 12-12 Reading and Interpreting IR Spectra (Solved Problems) 537 12-13 Introduction to Mass Spectrometry 541 12-14 Determination of the Molecular Formula by Mass Spectrometry 545... 

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