Laser flash photolysis silyl cations

When the reaction was conducted in O-deuteriated HFIP, (CF3)2CHOD, as a solvent, the deuterium was found exclusively at the 2-position of the 1,3-dimethoxybenzene 312. Laser flash photolysis at 248 nm irradiation carried out with 10 3 M solutions of substrates 311 with different silyl groups (SiMe3, SiMe2Ph, SiMePh2, SiMe2C6H4X-4 X = OMe, Me, F, I) show absorptions of the transient cations 313 with maxima at 380-390 nm and a weak band at 300 nm. The absorption spectra are similar to that of the parent 2,6-dimethoxybenzenium ion 314 (R = H) (kmax = 410 nm) but show a slight hyp-sochromic shift. 

Silicone Polymers - Laser flash photolysis studies on poly(silylenes) generates radical cations along with silyl radicals and polysiloxane composities for the space shuttle have been found to be stable to far UV light exposure. Linear polysiloxanes have been found to be more unstable than branched or crosslinked polymers while the transparency of poly(methylphenylsilane) increases with light exposure. Photooxidised polysiloxanes doped with iodine are converted into semiconductors. ... 

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