Matrix isolation study of the thermal and photochemical reaction of ozone with Trimethyl Indium

Highlights: ► First identification of monomeric H3COIn(CH3)2. ► Spectroscopic and theoretical characterization of H3COIn(CH3)2. ► Identification of downstream products of the reaction of O3 with (CH3)3In. ► Clarification of the initial steps in the mechanism of the gas phase reaction. - Abstract: The matrix isolation technique has been combined with infrared spectroscopy and theoretical calculations to explore the reaction of (CH3)3In with O3 over a range of time scales. Upon twin jet deposition (short reaction time), formation of the novel H3COIn(CH3)2 species along with a low yield of CH2O was observed. Subsequent UV irradiation greatly increased the yield of H3COIn(CH3)2 while the intensities of the CH2O bands were not affected. An extensive set of bands were seen for H3COIn(CH3)2 after irradiation and 18O spectroscopic data was obtained as well. The identification of this species was supported by theoretical calculations at the B3LYP/lanl2dz and B3LYP/dgdzvp levels of theory. Merged jet deposition (longer reaction times) led to high yield of H2CO, CH3OH and C2H6, identifications that were confirmed by 18O substitution. Mechanistic inferences for the initial steps of this reaction are discussed.