Fragmentation of Methylphenylsilane and Trimethylphenylsilane: A Combined Theoretical and Experimental Study

journal article in Web of Science

English

The electron impact ionization (EII) of methylphenylsilane (MPS), dimethylphenylsilane (DMPS) andtrimethylphenylsilane (TMPS) was investigated using the mass spectrometry technique. The composition of fragmentation products from MPS and TMPS measured in this work is interpreted with respect tothe ionization energy, appearance energies of fragments and bond dissociation energies of selected bonds.The results are compared to the previously published experimental data for DMPS. Comparison with thetheoretical bond dissociation energies calculated using the density functional theory (DFT) calculationsis presented. Using the combined experimental and theoretical approaches, we have focused our recentstudies on the common features as well as basic differences of the fragmentation schemes of all threemolecules. The elimination of the H2molecule, specific for MPS but rarely observed in the other two compounds, was also of high interest in our studies. It can run in two mechanisms: (i) loss of two hydrogensone-by-one and (ii) elimination of H2in one step. We can predict which mechanism is more probableaccording to the DFT calculated energy profile of reaction. The calculated predictions were in correlationwith the composition of fragmentation products determined experimentally from mass spectra.

Electron impact ionization, massspectrometry, methylphenylsilane, appearanceenergy, fragmentationmechanism, elimination of H2

AL MAHMOUD ALSHEIKH, A.; ŽÍDEK, J.; KRČMA, F.; PAPP, P.; LACKO, M.; MATEJČÍK, Š.

2015

15. 6. 2015

1387-3806

INTERNATIONAL JOURNAL OF MASS SPECTROMETRY

385

1

Kingdom of the Netherlands

1

12

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