Chemiluminescent reactions of fluorine atoms with inorganic iodides in the gas phase

Abstract

Visible chemiluminescence in the spectral range 200-900nm has been measured for the reactions of F atoms with a range of inorganic iodides studied at reduced pressures (ca. 0.7 mbar). There is only one emitter present in all cases uiz. IF*(B). The IF*(B) vibrational state distributions and rotational temperatures are essentially the same for all the systems studied. The yield of IF* can be substantially increased by adding O$('A) to the flame or by increasing the F atom concentration. It is suggested that the origin of IF*(B) in these reactions and other similar systems previously studied may be the recombination reaction of spin-orbit excited iodine atoms with ground-state fluorine atoms.

Rotational effects on the overtone-induced isomerization rate for CHD2NC .fwdarw. CHD2CN

“…These variations are somewhat smaller than those observed experimentally. The bandwidth of 0.01 cm"1 is the minimum spectroscopic bandwidth possible for a 6-Torr sample of this molecule on the basis of the pressure broadening of approximately 1 cm"1/atm observed in high-resolution fundamental spectra.31 At this narrow bandwidth, only [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] transitions contribute to the excited-state population. These calculations suggest that even significant variation of the excited distribution (major errors in the simulation) is unlikely to account for the discrepancy between calculations and experimental data.…”

“…Indeed, Zolotarev and co-workers have produced lasing from the IF(B) state by the optical excitation of IF(X) which was formed following the photolysis of CF3I/NF2/He mixtures.11,12 In a series of experiments by Raybone et al, various iodides were mixed with F atoms to yield IF(B) emission which was considerably enhanced by adding 02(' ) to the reaction flame. 13,14 The same group has also produced IF(B) emission by 248-nm photolysis of alkyl iodide/F2 mixtures. 15,16 From the results of these studies13"16 it has been suggested that IF(B) is formed either by the recombination of I*(2P1/2) and F atoms or by sequential excitation of IF(X) by I*.…”

Crossed-beam studies of some chemiluminescent reactions producing IF

“…The reactions F 2 + HI , CH 3 I , CH 2 12, CF 3 I have been studied by Estler, Lubman and Zare (3) under flow conditions, and their report is a very brief contribution to the General discussion of a Faraday Discussion. Many flow experiments have been done (17)(18)(19)(20)(21)(22) by the group of C. Whitehead, but the fluorine reactant was introduced in the atomic form, with only a small amount of fluorine molecules. This was also the case in a 1972 study by Schatz and Kaufman (8), and more recently in a work of Cha and Setser (23).…”