McMurry (Kap 15,8) - spectroscopy of Carboxylic acid + nitrile Flashcards
1
Q
What is the IR spectroscopy of carboxylic acids?
A
carboxylic acid have 2 characteristic IR absorptions - OH bond of the carboxylic acid gives absorption around 2500 to 3300 cm^-. The C=O bond give absorption between 1710-1760 cm^-.
The exact position depens on whether the acid is free (monomeric) or hydrogen bonded (dimeric). Free carboxylic acid (1760 cm^-2) and the dimeric, also more encountered is absorbed arounf (1710 cm^-1). Both the OH and the C=O is absorbed at 1710 cm^-1 (dimeric)
2
Q
Nitrile show an intense and regognizable C=_N bond absorption near 2250 cm^- for saturated compounds and 2230 cm^- for aromatic and conjugated molecules.
A
