Simulation of Vacuum Ultraviolet Absorption Spectra: Paraffin, Isoparaffin, Olefin, Naphthene, and Aromatic Hydrocarbon Class Compounds

Abstract

The advent of a new vacuum ultraviolet (VUV) spectroscopic absorption detector for gas chromatography has enabled applications in many areas. Theoretical simulations of VUV spectra using computational chemistry can aid the new technique in situations where experimental spectra are unavailable. In this study, VUV spectral simulations of paraffin, isoparaffin, olefin, naphthene, and aromatic (PIONA) compounds using time-dependent density functional theory (TDDFT) methods were investigated. Important factors for the simulations, such as functionals/basis sets and formalism of oscillator strength calculations, were examined and parameters for future PIONA compound simulations were obtained by fitting computational results to experimental spectra. The simulations produced satisfactory correlations between experimental observations and theoretical calculations, and enabled potential analysis applications for complex higher distillate fuels, such as diesel fuel. Further improvement of the methods was proposed.

Gas chromatography vacuum ultraviolet spectroscopy: A review

“…The use of experimental absorption spectra, combined with spectral library matching, and computed absorption spectra provided good results (Figure 3), however they concluded that improvements in computational methods are needed in order to derive more experimental-like spectra. In the recent work, Mao et al [28] This article is protected by copyright. All rights reserved.…”

Attenuated Total Reflection–Far-Ultraviolet Spectroscopy and Quantum Chemical Calculations of the Electronic Structure of the Top Surface and Bulk of Polyethylenes with Different Crystallinities

“…10 Very recently, Mao et al also investigated the absorption edge of various alkanes using a new benchtop FUV spectroscopic detector for gas chromatography and assigned the absorption in this region to Rydberg transitions. 21,22 They also reported that carrying out calculations without diffuse basis functions resulted in spectra that did not reproduce the experimental results well. 22 Morisawa et al showed that the absorption band of n-alkanes can be assigned to the s-Rydberg 3p transition by comparison with the results of quantum chemistry calculations.…”

Identifying Thermal Decomposition Products of Nitrate Ester Explosives Using Gas Chromatography–Vacuum Ultraviolet Spectroscopy: An Experimental and Computational Study

“…Additionally, time-dependent density functional theory (TDDFT) has been used to compare calculated and experimental VUV spectra. 17,27–29…”

“…Additionally, time-dependent density functional theory (TDDFT) has been used to compare calculated and experimental VUV spectra. 17,[27][28][29] Previous analysis of nitrate ester explosives such as ethylene glycol dinitrate (EGDN), nitroglycerine (NG), and pentaerythritol tetranitrate (PETN) at temperatures exceeding 240 C revealed various decomposition products such as nitric oxide, water, carbon monoxide, oxygen, and formaldehyde. 26,30 These decomposition products were determined via the VUV spectral database.…”