title: Ultraviolet photolysis of CH2I2 in methanol: O-H insertion and HI elimination reactions to form a dimethoxymethane product.
abstract: Ultraviolet photolysis of low concentrations of CH2I2 in methanol solution found that CH2I2 is converted into dimethoxymethane and some H+ and I- products. Picosecond time-resolved resonance Raman (ps-TR3) experiments observed that the isodiiodomethane (CH2I-I) photoproduct decayed faster as the concentration of methanol increases, suggesting that isodiiodomethane is reacting with methanol. Ab initio calculations indicate isodiiodomethane is able to react with methanol via an O-H insertion/HI elimination to form an iodoether (ICH2-O-CH3) and HI products. The iodoether can then further react via another O-H insertion/HI elimination reaction to form the dimethoxymethane (CH3-O-CH2-O-CH3) observed in the photochemistry experiments. A reaction mechanism consistent with these experimental and theoretical observations is proposed.
authors.affiliation: Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, PRC.
authors.forename: Xiangguo
authors.initials: X
authors.lastname: Guan
authors.forename: Xufeng
authors.initials: X
authors.lastname: Lin
authors.forename: Wai Ming
authors.initials: WM
authors.lastname: Kwok
authors.forename: Yong
authors.initials: Y
authors.lastname: Du
authors.forename: Yun-Liang
authors.initials: YL
authors.lastname: Li
authors.forename: Cunyuan
authors.initials: C
authors.lastname: Zhao
authors.forename: Dongqi
authors.initials: D
authors.lastname: Wang
authors.forename: David Lee
authors.initials: DL
authors.lastname: Phillips