Question

I know my structure is an aromatic aldehyde but I can't figure out which one? I have attached the H-NMR, C-NMR, and IR Spectrum, hopefully that helps!
INDEX HEIGHT 12.8 14.8 -13.1 113.3 102.1 110.9 -15.2 77.432 77.003 76.589 FREQUENCY PPM 15805.9 209.559 7810.0 103.548 6521.1 86.459 5840.3 77.432 5807.9 77.003 5776.7 76.589 4810.3 63.776 3153.8 41.814 2457.9 32.587 2251.0 29.844 2083.4 27.622 1682.2 22.304 22.304 62.7 55.2 48.4 48.8 126.0 - 41.814 32.587 29.844 27.622 -209.559 103.5 48 — 86.459 63.776 ppm

Answer 1

Observations from the Given Data:

1. There is a peak at 203 ppm in 13C NMR, which confirms the presence of aldehydic/carbonyl group.

2. Peak at 1715 cm-1 in IR also confirms the presence of carbonyl.

3. Peak in IR at 2957 cm-1 is due to sp3 hybridised CH.

4. However there is no peak of CHO on 1H NMR.

5. Peak at 7.26 ppm observed due to CDCl3

6. Peaks of Aromatic Carbon and Aromatic Hydrogens are also absent in 13C NMR (Peaks around 110-180 ppm absent) and 1H NMR (6-7 ppm) respectively.

7. Peak at 0.89ppm and 0.87 ppm could be due to two CH3

Inference

Compound is contains carbonyl group (possibly aldehyde). But there is no signature peak for aromatic carbon and hydrogen.

we can predict structure if HRMS of the compound is known.

Hopes.. this will help you.