[Dibutyl Phthalate Theoretical Analysis and Detection in Infrared]

Area of Science:

• Environmental Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Phthalate esters (PEs), including Di-n-butyl phthalate (DBP), are widely used as plasticizers.
• DBP can migrate from polymeric materials, leading to widespread environmental pollution.
• Accurate detection methods are crucial for monitoring DBP contamination.

Purpose of the Study:

• To assign the infrared vibration spectra of isolated Di-n-butyl phthalate (DBP).
• To provide a theoretical basis for the detection and analysis of DBP using computational methods.
• To validate Density Functional Theory (DFT) calculations against experimental infrared spectroscopy data.

Main Methods:

• Density Functional Theory (DFT) calculations using the B3LYP method at the 6-31G* level.
• Geometrical parameters and convergence criteria calculation for DBP.
• Comparison of simulated infrared spectra with experimental Fourier transform infrared (FTIR) spectra (400–4000 cm⁻¹).

Main Results:

• Theoretical calculations using DFT accurately predicted the geometrical parameters of DBP.
• Simulated infrared spectra showed strong agreement with experimental FTIR spectra.
• Linear fitting demonstrated a high correlation (R² > 0.99) between theoretical and experimental peak positions.

Conclusions:

• DFT calculations provide a reliable theoretical foundation for understanding DBP's infrared spectra.
• The high correlation validates the computational approach for DBP analysis.
• This research supports the development of enhanced methods for DBP detection and environmental monitoring.