Chemistry Spectroscopy

C-C single bond IR

around 1200, but NOT usually seen due to nonpolar nature

C—C double bond IR

a band/spike typically observed around 1600-1680. this depends on conjugation. congujation LOWERS frequency

isolated- 1640-1660

conjugated: 1620-1640

aromatic: 1600-1620

C—-C triple bond IR

2200, if there, usually moderate or weak (most likely C-N)

C-H stretch IR

around 3000

sp3 C-H (single bonded carbon)

right below 3000 (2800-3000)

sp2 C-H (double bond carbon)

left of/above 3000 (3000-3100)

sp3 C-H (triple bonded carbon)

sharp at 3300

Alcohols IR

OH stretch at 3300 BROAD

carboxylic acids

OH stretch at 3000, with C-H stretch, and C-O double bond stretch at 1700

amines IR

ONE NH spike around 3300

amides IR

two spikes around 3300/higher

nitrile IR

N—-C triple bond sharp stretch around 2200

C-N IR

1200, strong

C-N double bond

1650/1660, strong

C-N triple bond IR

>2200

how to distinguish OH with NH?

NH has sharp spikes

conjugated carbonyl frequencies

1685 (rather than >1700)

amide w/ carbonyl

c double bond o at 1630-1680