Spectroscopy and Lab techniques

Alcohol (OH)

3200-3500 cm-1

Large, broad peak

Amine (N-H)

3200-3500 cm-1

Sharp peak

Secondary amine (-NR2H): 1 peak

Primary amine (-NRH2): 2 peaks

Carboxylic Acid

(-COOH)

2500-3500 cm-1

Broad jagged peak

Nitrile (C≡N)

2200-2250 cm-1

Medium peak

Carbonyl (C=O)

1700-1750 cm-1

Large, sharp peak

Aromatic (C=C)

1450-1600 cm-1

Medium peak

Fingerprint Region

400-1500 cm-1

Complicated pattern of peaks

H NMR

Carboxylic acid (RCO₂H)

11–14 ppm

Aldehyde (RCHO)

9–10 ppm

Aromatic H

6.5–8.5 ppm

Phenol (PhOH)

6–8 ppm

sp² C–H (alkene H)

5–6.5 ppm

Amide N–H (RCONH)

5–9 ppm

Amine N–H (R₂NH)

1–5 ppm

Alcohol O–H (ROH)

1–5 ppm

sp³ C–H

0.5–4 ppm

C NMR

Ketone / Aldehyde C — RCOR, RCHO

190–235 ppm

Ester / Amide / Acid chloride / Carboxylic acid C — RCOOR, RCONH₂, RCOCl, RCOOH

150–180 ppm

sp² C — C=C

100–160 ppm

Aromatic C

90–150 ppm

sp³ C — C–C

0–100 ppm

Degrees of Unsaturation =

each pi bond is

1 degree of unsaturation

each ring is

1 degree of unsaturation

m/z ratio

mass to charge ratio

molecular ion peak is

the rightmost peak

it represents the compounds molecular mass

base peak is

the most stable molecular fragment

if M+ and M+2 peak are in a 1:1 height ratio

Br is present

if M+ and M+2 peak are in a 3:1 height ratio

cl is present

greater conjugation in uv vis

means longer wavelengths will be absorbed

higher max absorption (λmax)

more conjugated pi bonds

the larger the Rf value

the less polar it is

Rf =