Visible chemiluminescence from the high-pressure reactions of F atoms with CH3I and CH2I2
Abstract
Visible chemiluminescence in the region 400–890 nm was measured from the high-pressure (ca. 0.4 mbar) reactions of F atoms with CH3I and CH2I2. Emission was observed from electronically excited IF*(B), HCF*(Ã) and CH*(A) and from vibrationally excited HF‡(X). There are essentially no differences in the observed chemiluminescence spectra from the two reactions and no major dependence on the source of F atoms (discharge of F2+ He or CF4). A possible mechanism for the formation of IF* involves the intermediate species CH3IF or CH2I2F. It is suggested that HCF*, CH* and HF‡ may be formed by the reactions of F or F2 with CH or CH2 and such a mechanism may be applicable to all high-pressure fluorine reactions with substituted methanes. Some studies of chemiluminescence in other high-pressure systems (F + CH3Br, CH3OH, ICl and HI) are also reported.