infrared spectroscopy. what is infrared (ir) spectroscopy used for? to detect functional groups in...
TRANSCRIPT
INFRARED SPECTROSCOPY
What is infrared (IR) spectroscopy used for?
• To detect functional groups in all organic compounds and many inorganic compounds
• Can be used to identify polymers, plastics and resins
Assigning Peaks
• Peaks are assigned depending on what range they appear in, and whether they are broad or sharp.
• A correlation chart will be supplied.
Correlation chart for infrared spectroscopy
Bond Types of compound Range/ cm-1
C-H Alkanes, Alkenes, Aldehydes 3100-2800
O-H Alcohol 3700-3300
Carboxylic acid 3600-2500 broad
N-H Amine 3500-3100 sharp
C-O Alcohols, carboxylic acids. esters 1250-1050
C=O Aldehydes, ketones, carboxylic acids, esters
1850-1600
C=C Alkenes 1500-1600
C-Cl Chloroalkane 600-800
C-Br Bromoalkane 500-600
C-I Iodoalkane 500
An infrared spectrum
www.chemguide.co.uk
Fingerprint region
The fingerprint region is found on the right hand
side of an infrared spectrum from about 1500-500 cm-1. It can be used to compare two similar compounds.