IR & NMR spectroscopy

Double bond region 

1850-1630

aldehyde

two weak bands 2900-2700 cm^-1

carboxylic acid

very broad band, 3100-2600 cm^-1 AND double bond band ~1700 cm^-1

ester

two bands, usually strong, 1000-1300 cm-1

OH NH region

4000-2500 cm^-1

Alcohol 

Strong broad band present in 3600-3000 cm^-1 region

Primary Amine

Double medium bands present in 3300-3500 cm^-1 region

Ketone

one band ~1700 cm^-1, nothing in OH NH range

CH region

2850-3000 cm

Secondary Amine

Single medium band present in 3300-3500 cm^-1 region

Terminal Alkyne

~3300 cm-1, sp region, sharp (might see peak ~2200 cm-1 also)

Terminal Alkene

3000-3100 cm^-1,sp² region, sharp

alkane/sp3 CH

2950-2850 cm-1

triple bond region

2000-2500 cm-¹

Nitrile

Strong band 2280-2100 cm-¹

internal Alkyne 

weak band 2250-2100 cm-¹ (weaker than terminal)

Ether

C-O single bonds (1250-1050 cm^-1)

NH₂ bend

~1650 cm^-1

CO double bond

narrow band 1800-1650cm^-1

internal Alkene CC

Medium band ~1650-1550 CC bond

chemical shift for aldehyde

9-10

chemical shift for carboxylic acid

10-12

chemical shift phenyl

7.2 (6.5-8)

chemical shift vinylic

4-5

chemical shift

2.5-4.5

chemical shift allylic

1.5-2.5

chemical shift

2.5

chemical shift R-CH3

0.85

upfield

e- rich, shielded, smaller ppm

downfield

e- poor, deshielded, larger ppm

degree of unsaturation

(2C + 2 + N - X - H) / 2

signal integration

area under a signal is proportional to the relative # of Hs producing the signal

Signal multiplicity & coupling constant (J)

N+1 where N = # of equivalent H bonded to adjacent carbons