Solution Found!
All of the following compounds absorb infrared radiation
Chapter 20, Problem 14SP(choose chapter or problem)
All of the following compounds absorb infrared radiation between 1600 and \(1800 \mathrm{~cm}^{-1}\). In each case,
1. Show which bonds absorb in this region.
2. Predict the approximate absorption frequencies.
3. Predict which compound of each pair absorbs more strongly in this region.
Equation Transcription:
Text Transcription:
1800 cm^{-1}
C=C
CH_{2}CH_3
O=C
CH_{2}CH_3
C=C
CH_{2}CH_3
C=C
OCH_{2}CH_3
N=C
CH_{2}CH_3
C=C
CH_{2}CH_3
C=C
CH_3
H_{3}C
C=C
CH_{2}CH_{3}
Questions & Answers
QUESTION:
All of the following compounds absorb infrared radiation between 1600 and \(1800 \mathrm{~cm}^{-1}\). In each case,
1. Show which bonds absorb in this region.
2. Predict the approximate absorption frequencies.
3. Predict which compound of each pair absorbs more strongly in this region.
Equation Transcription:
Text Transcription:
1800 cm^{-1}
C=C
CH_{2}CH_3
O=C
CH_{2}CH_3
C=C
CH_{2}CH_3
C=C
OCH_{2}CH_3
N=C
CH_{2}CH_3
C=C
CH_{2}CH_3
C=C
CH_3
H_{3}C
C=C
CH_{2}CH_{3}
ANSWER:
Solution 14SP
The IR absorptions of the following compounds can be determine as:
(a)
1) In the above compound
C=C stretching is observed in the region of 1600-1800
C=O stretching is observed in the region of 1600-1800
2) The IR absorptions of the above the compounds are:
C=C stretching is observed at 1660
C=O stretching is observed at 1710
3) The functional group of the compound which has the greater value of the IR absorption (due to greater dipole moment) has the stronger absorption of IR radiation. So for the given functional groups C=O has stronger IR absorption.
(b)