Direct evidence for formation of unstable methoxy cyclosiloxanes [(CH3O)2SiO]2 (1) and [(CH3O)2SiO]3 (2) in the gas phase has been obtained by a mass-spectral study of the vacuum pyrolysis of 3,3-dimethoxy-6-oxa-3-silabicyclo[3.1.0]hexane (4). Intermediates 1 and 2 have been detected in the mass spectra of the pyrolysis products of 4 as the corresponding molecular ions, and identified from their exact masses and compositions. The metastable transitions recorded by B/E scan show the fragmentation trends of 1, 2 and 4 under electron impact (70 eV). The ionization energies (IE), determined for 1 (8.81 ± 0.1 eV) and 2 (8.50 ± 0.1 eV) are considerably lower than than the IE of linear methoxysubstituted silanes and alkanes.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry