CO2 laser excitation of triethylsilane: Time resolved luminescence of diethylsilyl radical

Article abstract of DOI:10.1002/kin.550260807

The infrared multiphoton excitation of triethylsilane in the gas phase, with a pulsed CO₂ laser at high intensities (I>700 MW/cm²), produced an intense luminescence. The spectrum and time profile of this luminescence was studied as a function of pressure, and laser frequency. The radiative lifetime of this emission was 357±10 ns, and the quenching rates by Cl₂ and NO were determined from lifetime measurements. A reasonable mechanism for the interpretation of this luminescence involves the initial infrared multiphoton decomposition of triethylsilane, followed by the secondary infrared multiphoton excitation of the primary photofragment diethylsilyl radical, which subsequently undergoes relaxation to an excited electronic state. The addition of O₂ resulted in a new chemiluminescence at shorter wavelengths, which corresponds to the SiO* chromophore group.