Which functional groups correspond to the characteristic peaks of the infrared spectrum (IR) of n-butyl acrylate?

Butyl acrylate infrared spectrum (IR) characteristic peak corresponding to which functional groups?

In the chemical industry, infrared spectroscopy (IR) analysis is a common detection technique that can effectively identify functional groups in substances. As an important chemical raw material, the infrared spectrum analysis of n-butyl acrylate can help to determine its structure and purity. In this paper, the infrared spectrum characteristic peaks of n-butyl acrylate will be analyzed in detail, and the corresponding functional groups will be revealed.

Structural overview of n-butyl acrylate

n-Butyl acrylate is a compound produced by esterification of acrylic acid with n-butanol. Its structure contains a carboxylate group (-COO-) and a propenyl group (CH2CHCH2-). This structure imparts unique physical and chemical properties to n-butyl acrylate, while allowing it to exhibit specific absorption peaks in the infrared spectrum.

Infrared Spectroscopy (IR) Fundamentals

Infrared spectroscopy produces a spectrogram by the absorption of infrared radiation at specific wavelengths by molecular vibrations. Different functional groups have different vibration frequencies, corresponding to the characteristic peaks in the spectrum. Analysis of these peaks can help determine the functional groups in the substance.

Analysis of Infrared Spectra of n-Butyl Acrylate

1. The characteristic peak of ester group (C = O) The ester group (C = O) in n-butyl acrylate exhibits a strong absorption peak in the infrared spectrum, usually located between 1730-1750 cms¹. This peak is due to the stretching vibration of C = O and reflects the presence of ester groups. The electronic environment of the ester group and the influence of adjacent groups may cause a slight change in the position of the peak.

2. C- O and O-C-O symmetrical telescopic vibration In the infrared spectrum, the C- O and O-C-O symmetrical stretching vibrations in the ester group appear as characteristic peaks in two regions. C- O symmetrical expansion vibration is usually between 600-800 cm¹, while O-C-O symmetrical expansion vibration occurs between 1050-1250 cm¹. The presence of these two regions further confirms the structure of the ester group.

3. The characteristic peak of double bond (C = C) The double bond in acrylic acid (C = C) shows a distinct absorption peak in the infrared spectrum, which is usually located between 1630-1680 cm≡¹. The intensity and position of this peak may be influenced by nearby groups, such as C- O or C = O interactions, resulting in a slight shift of the peak.

4. Symmetric and asymmetric stretching vibration of alkyl C- H The alkyl C- H bond in n-butyl acrylate shows symmetrical and asymmetrical stretching vibrations between 2800-3000 cm¹. Symmetrical telescoping vibrations typically occur at 2850-2950 cm¹, while asymmetrical telescoping vibrations are around 3000 cm¹. These peaks reflect the presence of alkyl groups in the alkenyl and ester groups.

practical application and significance

Infrared spectrum analysis plays an important role in detecting the purity and structure of n-butyl acrylate. By identifying these characteristic peaks, the presence of impurities or structural abnormalities in the sample can be quickly and accurately determined. This has important implications for quality control and R & D.

Conclusion

The IR characteristic peaks of n-butyl acrylate are closely related to its molecular structure. By analyzing the peaks in the 1730-1750 cm¹ (ester group C = O), 1050-1250 cm¹ and 600-800 cm¹ (C-O and O-C-O), and 1630-1680 cm¹ (double bond C = C), the functional group composition can be effectively determined. This analysis is not only of great value in quality control, but also provides reliable data support for research and development.