1,2-dimethylbenzene

Definition

1,2-dimethylbenzene, also known as o-xylene, is an aromatic hydrocarbon compound with two methyl groups attached to the benzene ring in the ortho position. It is an important industrial chemical and a component of gasoline and other fuels.

5 Must Know Facts For Your Next Test

1. The presence of two methyl groups in the ortho position on the benzene ring of 1,2-dimethylbenzene results in a unique set of $^{13}$C NMR signals.
2. The $^{13}$C NMR spectrum of 1,2-dimethylbenzene will show six distinct signals, corresponding to the six unique carbon environments in the molecule.
3. The two methyl carbon signals will appear at around $\delta$ 20-21 ppm, while the aromatic carbon signals will be observed in the $\delta$ 125-135 ppm range.
4. The coupling patterns and chemical shift values of the aromatic carbon signals in the $^{13}$C NMR spectrum can provide information about the substitution pattern of the benzene ring.
5. The symmetry of the 1,2-dimethylbenzene molecule leads to a simplified $^{13}$C NMR spectrum compared to other disubstituted benzene derivatives.

Review Questions

• Explain how the presence of two methyl groups in the ortho position on the benzene ring of 1,2-dimethylbenzene affects its $^{13}$C NMR spectrum.
  • The presence of two methyl groups in the ortho position on the benzene ring of 1,2-dimethylbenzene results in a unique set of $^{13}$C NMR signals. The two methyl carbon signals will appear around $\delta$ 20-21 ppm, while the aromatic carbon signals will be observed in the $\delta$ 125-135 ppm range. The coupling patterns and chemical shift values of the aromatic carbon signals can provide information about the substitution pattern of the benzene ring. Additionally, the symmetry of the 1,2-dimethylbenzene molecule leads to a simplified $^{13}$C NMR spectrum compared to other disubstituted benzene derivatives.
• Analyze how the number and position of substituents on the benzene ring of 1,2-dimethylbenzene influence the interpretation of its $^{13}$C NMR spectrum.
  • The number and position of substituents on the benzene ring of 1,2-dimethylbenzene have a significant impact on the interpretation of its $^{13}$C NMR spectrum. The presence of two methyl groups in the ortho position results in a unique set of signals, with the methyl carbon signals appearing around $\delta$ 20-21 ppm and the aromatic carbon signals in the $\delta$ 125-135 ppm range. The coupling patterns and chemical shift values of the aromatic carbon signals can provide information about the substitution pattern of the benzene ring, allowing for the identification of the specific isomer. Additionally, the symmetry of the 1,2-dimethylbenzene molecule leads to a simplified $^{13}$C NMR spectrum compared to other disubstituted benzene derivatives, making it easier to interpret the data.
• Evaluate the importance of understanding the $^{13}$C NMR characteristics of 1,2-dimethylbenzene in the context of characterizing and identifying organic compounds.
  • Understanding the $^{13}$C NMR characteristics of 1,2-dimethylbenzene is crucial in the context of characterizing and identifying organic compounds. The unique set of signals observed in the $^{13}$C NMR spectrum, with the methyl carbon signals around $\delta$ 20-21 ppm and the aromatic carbon signals in the $\delta$ 125-135 ppm range, can serve as a fingerprint for this specific isomer of dimethylbenzene. Additionally, the coupling patterns and chemical shift values of the aromatic carbon signals provide valuable information about the substitution pattern of the benzene ring, allowing for the differentiation of 1,2-dimethylbenzene from other disubstituted benzene derivatives. This knowledge is essential for the structural elucidation and identification of unknown organic compounds, which is a critical skill in organic chemistry.

Related terms

Aromatic Hydrocarbon: Aromatic hydrocarbons are a class of organic compounds characterized by the presence of one or more benzene rings in their molecular structure.

Ortho Substitution: Ortho substitution refers to the placement of substituents on adjacent carbon atoms of a benzene ring.

Methyl Group: A methyl group is a functional group consisting of a single carbon atom bonded to three hydrogen atoms (CH3).