Basic Infrared Spectra Interpretation

This helps determine the number of rings and/or multiple bonds

Molecular Formula

What is the general formula for saturated hydrocarbons

C_nH_2n+2

Number that indicates the degree of unsaturation in a molecule

Index of Hydrogen Deficiency

What number will you add if you have an Oxygen or Sulfur in your compound?

+0

What number will you add if you have an Nitrogen or Phosphorus in your compound?

+1

What number will you add if you have a halogen in your compound?

Halogens: F, Br, Cl, I

-1

What can you expect in your compound if the index=4?

A benzene ring

The formation of each ring or double bond causes the loss of how many Hydrogens?

2 Hydrogens

The 2 main regions of IR Spectra interpretation are:

Functional Group; Fingerprint

What is the base value of O-H

3600 cm^-1

What is the base value of C=O

1715 cm^-1

In a C-H aldehyde reading, there should be two weak peaks. What would be its values?

~2850 and 2750 cm^-1

The range of a C-H sp³ stretch

< 3000 cm^-1

The base value of an amine absorption

3400 cm^-1

What type of CH₃ bending has a value of ~1460 cm^-1 ?

Asymmetrical Bending