|sodium borohydride||acetic acid||acetic anhydride|
N-functional Groups 1H-NMR 09-Nov-2015
N-functional Groups 1H-NMR 10-Nov-2015
N-functional Groups 1H-NMR 18-Nov-2015
N-functional Groups 1H-NMR 19-Nov-2015
Sample Amide Product (not available for submission for credit)
Stock FID Amide Product (available for submission for credit, see laboratory manual for details)
Stock IR of Imine and Amide Products (available for submission for credit, see laboratory manual for details)
Q1) Why is the imine so brightly colored while the aldehyde and amine starting materials are not?
A1) Most organic compounds are not brightly colored, but the imine formed in this reaction is a chromophore with a bright orange. Color in imines and other organic chromophores can arise from an absorption of a photon to promote an electron from a π to π* orbital or a lone pair (n) to π* orbital. The energy of the photon is related to the HOMO-LUMO gap which generally decreases with increased conjugation leading to a red shift in the absorption as the conjugation increases.