Interpret unknown with IR spectroscopy, proton and carbon NMR? I think I’ve figu

Question

Interpret unknown with IR spectroscopy, proton and carbon NMR? I think I’ve figured it out but I wanted to confirm. Is this 1-chloro-2-methylbenzene?

Order of pictures: MS data, IR spectroscopy, proton NMR, magnified pictures of peaks in proton NMR, and carbon NMR.

rint Date: 08 Feb 2014 16:31:35 s Data Review Active Chromatogram and Spectrum Plots-2/8/2014 4:31 PM Molecular ion 126 Sample Trude Unknown 11 Scan Range: 1- 1742 Time Range: 1,62-8.81 min. Operator: CC Date: 2/5/2014 11:14 AM Sample ID: Trude Unknown 11 1 N:463 744e40- 2.7 126.0 1.165e+8 280 63.0 2.913e 7 3.82 39.0 1 44te+7 20 100

Explanation / Answer

Yes, it's 2-methylchlorobenzene.

The IR spectrum shows the methyl groups and the aromatic bands at region 2800-3100 cm-1 , there is also the pattern (overtones) for subtituted aromatic compound at 1600-2000 cm-1. The band at ~800 cm-1 may correspondto the Cl-C bond. There are not important bands for other functional groups.

The 1H-RMN spectrum shows at ~2.33 ppm the signal for the methyl group and the integration appears to correspond to the actual number of hydrogens, the multiplicity (singlet) is in line with the proposed structure (no adjacent hydrogens). The other signals are in the aromatic region, the integration corresponds to ~4 hydrogens and we can differenciate the inmediatley adjacent hydrogens to the chlorine and the methyl groups as two signals that integrate for one carbon each, while the farthest hydrogens overlap and integrate for two carbons.

The 13C-RMN spectrum shows the seven carbons, some of them are overlapped, specially the farthest ones, at 20 ppm we can see the signal for the methyl carbon. The other signal are in the aromatic region.

Finally, the molecular ion corresponds to 2-methylchlorobenzene.

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