The nuclear magnetic resonance (NMR) spectrum is a powerful analytical tool in chemistry, providing detailed information about the molecular structure, chemical environment, and dynamics of a compound. In this blog, we'll explore what the NMR spectrum of 2 - Nitroaniline looks like, drawing on our expertise as a 2 - Nitroaniline supplier.
Introduction to 2 - Nitroaniline
2 - Nitroaniline, also known as ortho - nitroaniline, is an aromatic compound with the molecular formula C₆H₅N₂O₂. It consists of a benzene ring with an amino group (-NH₂) and a nitro group (-NO₂) attached at the ortho positions (adjacent carbons on the benzene ring). This compound is widely used in the synthesis of dyes, pigments, and pharmaceuticals.
NMR Basics
NMR spectroscopy relies on the magnetic properties of certain atomic nuclei, such as ¹H (protons) and ¹³C (carbon - 13). When placed in a strong magnetic field and irradiated with radiofrequency waves, these nuclei absorb energy and undergo a transition between different spin states. The resulting absorption spectrum provides information about the chemical environment of the nuclei.
¹H NMR Spectrum of 2 - Nitroaniline
The ¹H NMR spectrum of 2 - Nitroaniline typically shows several distinct signals corresponding to the different types of protons in the molecule.
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Amino Protons (-NH₂): The amino group protons usually appear as a broad singlet in the range of 4 - 6 ppm. The broadness is due to the exchange of these protons with traces of water in the sample or with other protic solvents. The exact chemical shift can be influenced by factors such as hydrogen bonding and the solvent used.
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Aromatic Protons: The benzene ring protons in 2 - Nitroaniline give rise to a set of signals in the aromatic region, typically between 6.5 - 8.5 ppm. Since the amino and nitro groups are electron - donating and electron - withdrawing respectively, they affect the electron density around the benzene ring, leading to different chemical shifts for the protons.
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The protons ortho to the amino group will experience a different chemical environment compared to those ortho to the nitro group. The electron - donating amino group increases the electron density at the ortho and para positions, while the electron - withdrawing nitro group decreases it. As a result, the protons ortho to the amino group will be more shielded and appear at a lower chemical shift, while those ortho to the nitro group will be more deshielded and appear at a higher chemical shift.
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The coupling constants between the aromatic protons can also provide information about their relative positions on the benzene ring. For example, ortho - coupled protons typically have a coupling constant (J) of around 7 - 9 Hz, while meta - coupled protons have a smaller coupling constant (J ≈ 2 - 3 Hz).
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¹³C NMR Spectrum of 2 - Nitroaniline
The ¹³C NMR spectrum of 2 - Nitroaniline provides information about the carbon atoms in the molecule.
- Aromatic Carbons: The benzene ring carbons appear in the range of 110 - 160 ppm. The carbon atoms attached to the amino and nitro groups will have distinct chemical shifts. The carbon attached to the electron - donating amino group will be more shielded compared to the carbon attached to the electron - withdrawing nitro group.
- Carbonyl - like Carbons: Although 2 - Nitroaniline does not have a traditional carbonyl group, the carbon atoms in the nitro group can have an influence on the overall chemical shift pattern. The carbon atoms adjacent to the nitro group may experience a downfield shift due to the electron - withdrawing effect of the nitro group.
Factors Affecting the NMR Spectrum
Several factors can affect the NMR spectrum of 2 - Nitroaniline:
- Solvent: Different solvents can interact with the 2 - Nitroaniline molecule in different ways. For example, polar solvents like DMSO - d₆ can form hydrogen bonds with the amino group, which can shift the chemical shift of the amino protons. Non - polar solvents like CDCl₃ may result in a different spectrum due to the absence of such interactions.
- Temperature: Temperature can also influence the NMR spectrum. At higher temperatures, the exchange rate of the amino protons may increase, leading to a further broadening of the signal. Additionally, temperature can affect the conformation of the molecule, which in turn can influence the chemical environment of the nuclei.
Comparison with Related Compounds
Comparing the NMR spectrum of 2 - Nitroaniline with related compounds can provide further insights. For example, 4 - Nitroaniline has the amino and nitro groups in the para positions. The ¹H NMR spectrum of 4 - Nitroaniline will have a different pattern of aromatic proton signals compared to 2 - Nitroaniline because of the different electronic effects on the benzene ring.
Applications of NMR in 2 - Nitroaniline Analysis
NMR spectroscopy is a valuable tool for the analysis of 2 - Nitroaniline in our role as a supplier.
- Quality Control: We use NMR to ensure the purity of our 2 - Nitroaniline products. Any impurities present in the sample will show up as additional signals in the NMR spectrum, allowing us to detect and quantify them.
- Structural Confirmation: NMR helps us confirm the structure of the synthesized 2 - Nitroaniline. By comparing the experimental spectrum with the expected spectrum based on the proposed structure, we can verify the identity of the compound.
Other Related Compounds in Our Portfolio
As a supplier, we also offer other related compounds that are important in the pharmaceutical and chemical industries. For example, Hexamethyldisiloxane in Electronics is widely used in the electronics industry as a solvent and a surface - active agent. Another compound is 4 - Bromofluorobenzene, which is used in the synthesis of various organic compounds.
Conclusion
The NMR spectrum of 2 - Nitroaniline is a complex but informative fingerprint of the molecule. The ¹H and ¹³C NMR spectra provide detailed information about the chemical environment of the protons and carbon atoms, which is crucial for understanding the structure and properties of the compound. As a 2 - Nitroaniline supplier, we rely on NMR spectroscopy for quality control and structural confirmation of our products.
If you are interested in purchasing 2 - Nitroaniline or any of our other products, we invite you to contact us for further discussions about your requirements. Our team of experts is ready to assist you in finding the right solutions for your applications.
References
- Silverstein, R. M., Webster, F. X., & Kiemle, D. J. (2014). Spectrometric Identification of Organic Compounds. Wiley.
- Pavia, D. L., Lampman, G. M., Kriz, G. S., & Vyvyan, J. R. (2015). Introduction to Spectroscopy. Cengage Learning.