Matrix Isolation Study of the Photochemically Induced Reaction between Iodoethane and Ozone Trapped in Solid Argon at 16 K. Infrared Spectra of Iodosoethane (C₂H₅IO), Iodylethane (C₂H₅IO₂), Ethyl Hypoiodide (C₂H₅OI), Hydrogen Hypoiodide (HOI), Hydrogen Iodide, and Ethanal Complexes

Abstract

The reactions of ozone with iodoethane isolated in argon matrices at 16 K and the subsequent photochemical reactions are reported. A molecular complex between ozone and iodoethane is formed on codeposition, but irradiation at wavelengths longer than 800 nm leads to the formation of the photoproduct iodosoethane, C 2 H 5 -IO. Further photolysis with radiation of wavelengths longer than 650 nm yields the photoproduct iodylethane, C 2 H 5 IO 2 . Radiation of wavelengths longer than 350 nm produces ethyl hypoiodide, hydrogen hypoiodide, and ethanal. Subsequent Pyrex-filtered photolysis increases the yield of ethanal. After quartz-filtered photolysis, hydrogen iodide is formed and the yield of ethanal increases. The ethanal so produced forms complexes with hydrogen iodide which can be distinguished by sample annealing. The products were identified by employing deuterated iodoethane, 18 O 3 , and scrambled ozone ( 16 O 3-x 18 O x ) made from 50:50 16 O 2 / 18 O 2 .

Visible-light-Induced Reaction of an Ozone–Trimethylamine Complex Studied by Matrix-Isolation IR and Visible Absorption Spectroscopies

“…Two photoreaction processes produce highly reactive species O­( 1 D) with O 2 from O 3 by irradiations at λ < 310 and 411 nm. − Although another process to produce O­( 3 P) and O 2 from O 3 by longer-wavelength irradiation is also familiar, it is not of much importance with reference to the atmosphere because the transition coefficient is either very low or is optically inhibited. However, some researchers reported that molecular complexes composed of O 3 and several molecules like olefin, ethylene, dimethylsulfide, and so on , have intense absorption bands in the visible-light region, in contrast to the O 3 monomer, and that visible-light-induced oxygen-atom transfer from O 3 to the counter molecule can occur in these complexes. − For example, an O 3 –ICl complex yields OICl by visible-light irradiation between wavelengths 470 and 750 nm, and an O 3 -dimethylsulfide complex yields dimethylsulfoxide upon red-light irradiation (λ = 700–740 nm) . The enhanced visible-light absorption and photoreaction mechanism of O 3 -molecule complexes are interesting in molecular chemistry.…”

Photochemical Reaction of Ozone with 2-Iodopropane and the Four Polyfluoroiodoethanes C2F5I, CF3CH2I, CF2HCF2I, and CF3CFHI in Solid Argon at 14 K. FTIR Spectra of the Iodoso-Intermediates (Z−IO), the Iodyl-Intermediates (Z−IO2), and the Various Complexes (CH3)2CO···HI, CF3C(O)H···XI, CF2HC(O)F···IF, and CF3C(O)F···XI (Where X = H or F)

“…Weak bands belonging to this group (Table ) are detected at 3446.4 and 3445.3 cm -1 . On the basis of the 18 O-shifts (3.5 and 10.8 cm -1 respectively) and the wavenumbers, these bands clearly arise from O−H stretches. The other weak band in this group at 578.8 cm -1 ( 18 O-shift of 27.8 cm -1 ) is assigned to an O−I vibration.…”

“…pentafluoroiodoethane, 1,1,1-trifluoroiodoethane, 1,1,2,2-tetrafluoroiodoethane, and 1,1,1,2-tetrafluoroiodoethane. The photochemical reactions of these four precursors with ozone are expected to produce the fluoro-analogues of the −IO x , −OI, and carbonyl species reported in the reaction between iodoethane and ozone . For example, if iodoso-species (Z−IO) could be detected as products in each case, it should be possible to compare both their photochemical and spectral behavior with that of analogous species. − It has been proposed that a five-membered ring intermediate is formed in the gas-phase reaction between ozone and iodoethane.…”

Photoreactions of Ozone–Tetrahydrothiophene, Ozone–Pyrrolidine, and Ozone–Thiazolidine Complexes Studied Using Matrix-Isolation IR and Visible Absorption Spectroscopies

“…More interestingly, visible-light irradiation corresponding to the electronic transition band induces O atom transfer from O 3 to the paired molecule in the low-temperature matrix. It is particularly common that the O atom combines with the lone pair of the paired molecule in the primary photoreaction process. − ,− For instance, O 3 -ClBr yields ClBrO upon laser irradiation at 870 nm, red-light photolysis of O 3 -PCl 3 and O 3 -PBr 3 yields OPCl 3 and OPBr 3 , respectively, and O 3 -C 2 H 5 I produces C 2 H 5 IO upon irradiation at λ > 800 nm . Although the electronic transition-enhanced mechanism and visible-light-induced photoreaction mechanism of O 3 -molecule complexes are interesting in molecular science, they have not yet been elucidated because the accurate theoretical analysis of O 3 and its complexes is still difficult, , while only a few experimental studies on their photoreactions have been published to date. − ,− …”

“…7−9,11−18 For instance, O 3 -ClBr yields ClBrO upon laser irradiation at 870 nm, 11 red-light photolysis of O 3 -PCl 3 and O 3 -PBr 3 yields OPCl 3 and OPBr 3 , respectively, 12 and O 3 -C 2 H 5 I produces C 2 H 5 IO upon irradiation at λ > 800 nm. 13 Although the electronic transitionenhanced mechanism and visible-light-induced photoreaction mechanism of O 3 -molecule complexes are interesting in molecular science, they have not yet been elucidated because the accurate theoretical analysis of O 3 and its complexes is still difficult, 19,20 while only a few experimental studies on their photoreactions have been published to date. 6−18,21−26 We have focused on the photoreactions and interaction of O 3 with S and N atoms in the paired molecules of these complexes, 7−9 dimethylamine-N-oxide, and trimethylamine-N-oxide during the primary process.…”