Question

Но CI

Please fill-in the NMR

Answer 1

Structure of 4-chlorocinnamic acid:

OH CI (E)-3-(4-chlorophenyl)acrylic acid (or) 4-chlorocinnamic acid

¹H-NMR of 4-chlorocinnamic acid:

7.45 Н 7.68 7.62 OH 12.05 H 7.88 6.27 7.62 (E)-3-(4-chlorophenyl)acrylic acid (or) 4-chlorocinnamic acid 10 12 PPM 6.27, 1H, d 7.45, 1Hd O Aromatic Hydrogen 12.05, H, s

¹H-NMR of 4-chlorocinnamic acid gives 5 peaks. Aromatic proton have two chemically different hydrogen, aromatic hydrogen ortho to chlorine shows upfield peak and other two hydrogen give downfield peak, both gives doublet.

COOH shows singlet peak at 12.05ppm, alkene hydrogen have two chemically different environment, one shows downfield with doublet splitting and other shows upfield with doublet splitting.

¹³C-NMR of 4-chlorocinnamic acid:

129.0 144.2 171.5 128.7 OH 133.3 118.5 129.0 133.5 CI 128.7 (E)-3-(4-chlorophenyl)acrylic acid (or) 4-chlorocinnamic acid 140 160 120 180 100 PPM 80 60 40 20 HOOO Alkene C Aromatic C Aromatic C Alkene C

It gives 6 peaks.

Mass Spectrum:

Molecular ion peak or Base peak of 4-chlorocinnamic acid

OH CI (E)-3-(4-chlorophenyl)acrylic acid m/z: 182.01 (100.0%), 184.01 (32.0% Molecularion peak at 182, M+2 peak at 184 in 3:1 ratio

Fragmentation ion:

1.

OH CI Exact Mass: 182.01 Chemical Formula: CoHgC1O Exact Mass: 165.01

2.

Chemical Formula: CoH,O2 Exact Mass: 147.04 OH OH Exact Mass: 182.01

3.

он Chemical Formula: CgHCl Exact Mass: 182.01 Exact Mass: 137.02

4.

гон CI Exact Mass: 182.01 Chemical Formula: C7H6C1 Exact Mass: 125.02

5.

Chemical Formula: C-H Exact Mass: 91.05

6.

Chemical Formula: CH5' Exact Mass: 77.04