Question

1. Infrared spectra analysis a. Label important functional groups above 1500 cm anthraldehyde acid. in the IR spectrum of 9- 2000 b. Label important functional groups above 1500 cm Wittig product: in the IR spectrum of the WIN 1000 cm-1 2000 C. Based on the differences between the starting material and product spectra, how do we know the product was actually formed?:

Answer 1

Solution:

a. IR of 9-anthraldehyde:

Labelling of the important functional groups above 1500cm-1 in the IR spectrum of 9-anthraldehyde.

Sr. No.	Frequency	Assignment
1	1622.87cm-1 (weak, sharp)	Conjugated C=C, aromatic
2	1665.38cm-1 (strong, sharp)	Conjugated C=O
3	2771.90cm-1 (weak, broad)	Aldehyde C-H
4	3025.88cm-1 (weak, broad)	sp2 C-H, aromatic

b. IR of Wittig:

Labelling of the important functional groups above 1500cm-1 in the IR spectrum of Wittig.

Sr. No.	Frequency	Assignment
1	1631.84cm-1 (medium, sharp)	Conjugated C=C , aromatic
2	1710.82cm-1 (strong, sharp)	Conjugated C=C, aliphatic
3	2984.85cm-1 (weak, broad)	Terminal vinyl C-H
4	3049.71cm-1 (weak, broad)	sp2 C-H, aromatic