Qualitative and quantitative characterization of a complex mixture of hexylbenzenes by 13C nuclear magnetic resonance and gas chromatography-mass spectrometry

Summary A considerable amount of byproducts is formed in the production of isopropylbenzene (cumene). Recently, a distillation fraction of these byproducts became commercially attractive which justified its compositional analysis. All the signals in the complex ¹³C nuclear magnetic resonance (NMR) spectrum of this material have been assigned. The mass spectra of the individual constituents were recorded by the application of capillary gas chromatography-mass spectrometry. The data obtained with both analytical techniques revealed that the product is composed of a complex mixture of 3 isomeric diisopropylbenzenes and 10 different hexyl-substituted benzenes. The mass spectra and carbon-13 NMR chemical shift data of most of the compounds presented here have not been previously reported. NMR data of all possible butyl- and a number of pentyl-substituted benzenes are included in this report for assignment purposes. Quantitative studies on this material and some of its distillation fractions by ¹³C NMR and gas chromatography enabled the assignment of individual peaks in the gas chromatogram.

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Qualitative und quantitative Charakterisierung eines komplexen Gemisches von Hexylbenzolen durch ¹³C-NMR und GC/MS