Thou Shalt Not Forget: Organic Chemistry Edition

Alcohol

-OH (hydroxy group)

Aldehyde

C=O (carbonyl group with hydrogen

Alkane

single bond (not functional group)

Alkene

double bond

Alkyne

triple bond

Amide

-CONH2, -CONHR, -CONR2

Amine

-NH2 (amino group)

Anhydride

Arene

aromatic ring

Carboxylic acid

-COOH

Ester

-COOR

Ether

-OR (alkoxy group)

Ketone

-C=O (carbonyl group)

Aldehyde

Halide

-F

- Cl

- Br

- I

hydroxyl

R-OH

Carbonyl

C=O

Imine

C=N

Nitrile

C triple bond N

Ketone

RCOR

Sulfoxide

Thiol

R-SH

Sulfide

R-S-R

Disulfide

R-S-S-R

Monophosphate

Diphosphate

Thioester

R-C(=O)-S-R

Acid Chloride

R-C=O-Cl

IR Spectrum Range of Functional Group Bond:

alkane C-H (sp^3)

2850-3000 cm-1

Shape: often strong

IR Spectrum Range of Functional Group Bond:

Alkene C-H (sp^2)

3000-3100 cm-1 or 1600-1650 cm-1

Shape: sharp

Intensity: medium

IR Spectrum Range of Functional Group Bond:

alkyne C-H (sp)

3300 cm-1 or 2100-2200 cm-1

Shape: sharp

Intensity: medium

IR Spectrum Range of Functional Group Bond:

aromatic C=C

1475-1600 cm-1

Shape: sharp

Intensity: medium

IR Spectrum Range of Functional Group Bond:

Nitrile C=N

2200-2300 cm-1 or 1000-1250 cm-1 medium

Shape: broad

Intensity: medium

IR Spectrum Range of Functional Group Bond:

Alcohol O-H

3300 cm-1

Shape: broad, smooth

Intensity: strong

IR Spectrum Range of Functional Group Bond:

Amine N-H

1650-1700 cm-1 strong or 3300-3500 cm-1 medium or 1000-1200 cm-1 medium

Shape: medium

Intensity: broad

IR Spectrum Range of Functional Group Bond:

Ester C=O

1740 cm-1 or 1000-1300 cm-1

Shape:

Intensity: strong

IR Spectrum Range of Functional Group Bond:

aldehyde C=O

1730 cm-1 or 2700, 2800 cm-1

Shape: strong or medium

Intensity: -

IR Spectrum Range of Functional Group Bond:

ketone C=O

1720 cm-1

Shape: strong

Intensity: -

IR Spectrum Range of Functional Group Bond:

carboxylic acid C=O

1710 cm-1 or 2500-3500 cm-1

Shape: strong, jagged and very broad

Intensity: -

IR Spectrum Range of Functional Group Bond:

amide C=O

1650 cm-1 or 3300 cm-1

Shape: broad

Intensity: strong

IR Spectrum Range of Functional Group Bond:

alkyl halide C-Cl

600-800 cm-1 or 500- 600 cm-1

Shape: Strong

Intensity: Strong

3000 cm-1

IR Spectrum analysis steps (1-5)

1. Distinguish C-H stretches of alkanes, alkenes, and alkynes by their position relative to ________

1600-1650 cm-1

IR Spectrum analysis steps (1-5)

2. A sharp peak at ____-____cm-1 suggests a C=C stretch

3300 cm-1

IR Spectrum analysis steps (1-5)

3. Look at _____cm-1 for O-H and N-H stretches (carboxylic acid O-H stretches occur over a broader range of 2500-3500 cm-1)

2200 cm-1

IR Spectrum analysis steps (1-5)

4. Bands near _____ cm-1 suggest a triple bond

1650-1800 cm-1

IR Spectrum analysis steps (1-5)

5. A strong band in the ____-____ cm-1 region indicates a carbonyl

a. absence

b. presence

Key principle in IR:

The (a) ______ of IR bands in a spectrum often tells us just as much as their (b) _______.

4000-1500 cm-1

IR diagnostic or characteristic region range

____-____ cm-1

1500-400 cm-1

IR fingerprint region range:

____-____ cm-1

Bond strength is directly proportional to the frequency, so (a) stronger bonds vibrate (b) faster and absorb IR light of (c) higher frequency.

Hooke's Law: Bond strength is directly proportional to the frequency, so (a) _______ bonds vibrate (b) _______ and absorb IR light of (c) _______ frequency.

According to Hooke's Law, reduced mass is indirectly proportional to the frequency, so bonds with (a) lighter atoms vibrate (b) faster and absorb IR light of (c) higher frequency

According to Hooke's Law, reduced mass is indirectly proportional to the frequency, so bonds with (a)_______ atoms vibrate (b)________ and absorb IR light of (c)________ frequency