Br Radicals Research Articles

Self- and N2-broadening of CH3Br ro-vibrational lines in the ν2 band: The J and K dependence

Methyl bromide (CH3Br) is the major source of inorganic bromine in the atmosphere and contributes significantly to ozone depletion. Indeed, CH3Br is dissociated by UV radiation, producing Br radicals that catalyze the destruction of ozone. In this paper, we report measured Lorentz self- and N2-broadening coefficients of CH3Br in the ν2 fundamental band using a mono-spectrum non-linear least squares fitting of Voigt profiles which appeared to properly model the observed molecular line shapes within the noise level. These measurements were made by analyzing 12 laboratory absorption spectra recorded at high resolution (0.005, 0.003 or 0.002cm−1) using the Fourier transform spectrometer Bruker IF125HR located at the LISA facility in Créteil. The spectra were obtained at room temperature using a White-type multipass cell with an optical path of 0.849m and various pressures. We have been able to determine the self- and N2-broadening coefficients of 948 ν2 transitions with quantum numbers as high as J=49 and K=10. The measured self-broadening coefficients range from 0.1542 to 0.4930cm−1atm−1 and the N2-broadening coefficients range from 0.0737 to 0.1284cm−1atm−1 at 295K. The accuracy of the broadening coefficients measured in this work is between 4% and 8%, depending on the studied transition. Comparisons with measurements taken in the ν5 and ν6 bands of CH3Br did not show any clear vibrational dependence. The J and K dependences of the self- and N2-broadening coefficients have been observed and the rotational K dependence has been modeled using empirical polynomial expression. On average, the empirical expression reproduce the measured broadening coefficients to within 6%. The data obtained represent a significant contribution to the determination of broadening coefficients of CH3Br useful for atmospheric remote sensing and applications.

Influence of Oxygen Addition and Wafer Bias Voltage on Bromine Atom Surface Reaction in a HBr/Ar Inductively Coupled Plasma

The influence of the wafer surface material and wafer bias voltage on the Br radical density in HBr/Ar and HBr/Ar/O2 inductively coupled plasmas was investigated by appearance mass spectrometry. By increasing the bias voltage, a monotonic decrease in the Br radical density was observed irrespective of the surface material (Si, Al2O3) of the wafer. A drastic increase in Br radical density was observed after O2 addition to HBr/Ar plasma in the case of a bare Si wafer, whereas almost the same density was observed in the case of an Al2O3-sputtered Si wafer. X-ray photoelectron spectroscopy (XPS) analysis indicated that O2 addition promotes oxide formation on the Si surface. Measurement of the decay time constant for a Br radical after turning off the plasma indicated that O2 addition results in a longer decay time constant, suggesting the decrease of the surface loss probability of Br radicals for the surface-oxidized Si surface.

Striking influence of chain structure of polyethylene on the formation of cup-stacked carbon nanotubes/carbon nanofibers under the combined catalysis of CuBr and NiO

A one-pot approach was used to convert polyethylene (PE) with different chain structures into carbon nanomaterials (CNMs) under the combined catalysis of CuBr and NiO at 700°C, including linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and high density polyethylene (HDPE). The effect of chain structure of PE on the yield, morphology, microstructure, phase structure and thermal stability of CNMs, including cup-stacked carbon nanotubes (CS-CNTs) and carbon nanofibers (CNFs), were investigated by scanning electron microscope, transmission electron microscope (TEM), high-resolution TEM, X-ray diffraction, Raman spectroscopy and thermal gravimetric analysis. In addition, the degradation products from different chain structures of PE under the catalysis of CuBr were analyzed by gas chromatography and gas chromatography–mass spectrometry. It was demonstrated that the branched structure played an important effect in the degradation products of PE. The dehydrogenation and aromatization of LLDPE were remarkably promoted by Br radicals from the decomposition of CuBr to form a large amount of light hydrocarbons and a relatively small amount of aromatics, favoring the formation of long and straight CS-CNTs. However, the degradation of LDPE was not obviously influenced by Br radicals due to its high extent of branched structure, while the random cleavage of HDPE was accelerated with the formation of a lot of olefins with long chains, resulting in the formation of short and winding CNFs. This work will contribute to the conversion of mixed waste polyolefin into high value-added CNMs.

Theoretical study of the reaction of CH2XO (X = F, Cl, Br) radicals with the NO radical

In this paper, we focus on the multiple-channel reactions of CH(2)XO (X = F, Cl, Br) radicals with the NO radical by means of direct dynamic methods. All structures of the stationary points were obtained at the MP2/6-311+G(d,p) level and vibrational frequency analysis was also performed at this level of theory. The minimum energy path (MEP) was obtained via the intrinsic reaction coordinate (IRC) theory at the MP2/6-311+G(d,p) level, and higher-level energetic information was refined by the MC-QCISD method. The rate constants for the three hydrogen abstraction reaction channels over the temperature range 200-1,500 K were calculated by the improved canonical variational transition state theory (ICVT) with a correction for small-curvature tunneling (SCT). The rate constants calculated in this manner were in good agreement with the available experimental data, and the three-parameter rate-temperature formulae for the temperature range 200-1,500 K were k(1a)(T) = 0.32 × 10(-18) T(1.83) exp(1748.54/T), k(2a)(T) = 0.22 × 10(-19) T(2.19) exp(1770.19/T), k(3a)(T) = 0.88 × 10(-20) T(2.20) exp(1513.82/T) (in units of cm(3) molecule(-1) s(-1)).

Theoretical study of the low-lying electronic states of CCCF radical and its ions

The low-lying electronic states of the CCCF radical and its ionic states have been investigated systematically using the complete active space self-consistent field (CASSCF) and multiconfiguration second-order perturbation theory (CASPT2) methods in conjunction with aug-cc-pVTZ basis set. To investigated the Renner–Teller effect on the CCCF radical, Cs symmetry was used for CCCF. The CCCF has been found to have a X2A′ ground state with rotational constant B¯=4500.5MHz, which is in good agreement with the experimental values of 4555.8043MHz. The calculations of vertical excitation energies of CCCF at 2.893 and 4.180eV are attribute to the X2A′→32A″ and X2A′→52A′, respectively, which has larger oscillator strengths. The ionization potentials of CCCF are computed in order to provide a theoretical guidance to the photoelectron spectrum (PES) of the CCCF radical. The first adiabatic electron affinity (AEA) of CCCF is predicted to be 2.671eV. A comparison of the geometries and bonding among the CCCX (X=F, Cl, and Br) radicals presents the ground state X2A′ of CCCX can be described as allenic structures with the unpaired electron on the C3 atom, while the excited state 12A″ (12Π) of CCCX have the linear acetylenic structures with the unpaired electron on the C1 atom. The barriers to linearity decrease as follows: ΔE (CCCF)<ΔE (CCCCl)<ΔE (CCCBr).

Radiation induced oxidation of hydroxy indoles by NO and Br radicals: effect of pH

AbstractThe reactions of NO and Br radicals with 5‐hydroxyindole (HIn), 5‐hydroxytryptophol (HTpl), 5‐hydroxytryptophan (HTpn) and 5‐hydroxytryptamine (HTpe) were studied using pulse radiolysis. The rate constants for their reaction with NO radical were found to vary from 105 to 107 dm3 mol−1 s−1 in the pH range 5–9 but a higher value (k = 1.4 ± 0.01 × 108 dm3 mol−1 s−1) was noticed in HTpe at pH 9. The gradual increase in reactivity with pH is due to the decrease in the reduction potentials of indoloxyl radicals with E = 0.55 V at pH 9. In contrast, the rate constants with Br radical were found to be diffusion controlled and remained unaffected by the pH. The transient spectra measured are attributed to the indoloxyl radical formed on oxidation with λmax at 420 nm. The indoloxyl radicals further react with the parent hydroxy indole derivative forming the radical adduct and their decay was found to be pH dependent in derivatives containing an amino group. At pH 5, no decay of the radical adducts was seen in all derivatives up to 5 ms whereas those with the amino group decayed faster at pH 9. The total yields of the oxygen centred and carbon centred radicals formed in the reaction of NO radical with hydroxy indoles were found to be nearly equal to G(NO). Our results suggest that NO radical is inefficient in oxidizing hydroxy indoles under physiological conditions preventing the formation of toxic dimers of indole derivatives. Copyright © 2010 John Wiley &amp; Sons, Ltd.

A DFT Study on the Mechanism of the Coupling Reaction between Chloromethyloxirane and Carbon Dioxide Catalyzed by Re(CO)5Br

The detailed mechanism of the experimentally observed formation of five-membered cyclic carbonates in the coupling reaction between chloromethyloxirane and CO2 catalyzed by the Re(CO)5Br complex is revealed by means of density functional theory (DFT) calculations. All possible pathways are examined, and their corresponding energetics are demonstrated. Our calculations indicate that the real active catalyst is the unsaturated complex Re(CO)4Br rather than free radical species (Re(CO)5 or Br radicals). The preferred mechanism (path I) for the catalytic production of cyclic carbonates can be divided into three main stages involving epoxide oxidative addition, carbon dioxide insertion, and reductive elimination of cyclic carbonate, none of which contains significantly large barriers. Our results provide support for Jiang’s proposal that the reaction proceeds through the reactive oxametallacyclobutane 2b. Furthermore, we have found CO dissociation from 2b is an essential step, which facilitates CO2 coordinatio...

Unimolecular Reactions of CH2BrCH2Br, CH2BrCH2Cl, and CH2BrCD2Cl: Identification of the Cl−Br Interchange Reaction

The recombination reactions of CH(2)Br and CH(2)Cl radicals have been used to generate vibrationally excited CH(2)BrCH(2)Br and CH(2)BrCH(2)Cl molecules with 91 kcal mol(-1) of energy in a room-temperature bath gas. The experimental unimolecular rate constants for elimination of HBr and HCl were compared to calculated statistical rate constants to assign threshold energies of 58 kcal mol(-1) for HBr elimination from C(2)H(4)Br(2) and 58 and 60 kcal mol(-1), respectively, for HBr and HCl elimination from C(2)H(4)BrCl. The Br-Cl interchange reaction was demonstrated and characterized by studying the CH(2)BrCD(2)Cl system generated by the recombination of CH(2)Br and CD(2)Cl radicals. The interchange reaction was identified from the elimination of HBr and DCl from CH(2)ClCD(2)Br. The interchange reaction rate is much faster than the rates of either DBr or HCl elimination from CH(2)BrCD(2)Cl, and a threshold energy of congruent with43 kcal mol(-1) was assigned to the interchange reaction. The statistical rate constants were calculated from models of the transition states that were obtained from density functional theory using the B3PW91 method with the 6-31G(d',p') basis set. The model for HBr elimination was tested versus published thermal and chemical activation data for C(2)H(5)Br. A comparison of Br-Cl interchange with the Cl-F and Br-F interchange reactions in 1,2-haloalkanes is presented.

Photochemical Reaction Pathways of Carbon Tetrabromide in Solution Probed by Picosecond X-ray Diffraction

We report a liquid-phase time-resolved X-ray diffraction study that resolves the molecular structures of the short-lived intermediates formed in the photodissociation of tetrabromomethane in methanol. Time-resolved X-ray diffraction can detect all chemical species simultaneously, and the diffraction signal from each chemical species can be quantitatively calculated from molecular structures and compared with experimental data with high accuracy and precision. The photochemistry of carbon tetrahalides has long been explored to describe their reactions in the natural environment due to its relevance to ozone depletion. Excited with an ultraviolet optical pulse, the complicated photodissociation dynamics of CBr4 was followed in a wide temporal range from picoseconds up to microseconds and associated rate coefficients were determined by analyzing time-resolved diffraction patterns accumulated from 100 ps X-ray pulses. The homolytic cleavage of one C-Br bond in the parent CBr4 molecule yields the CBr3 and Br radicals, which escape from the solvent cage and combine nongeminately to form C2Br6 and Br2, respectively. C2Br6 eventually decays to give C2Br4 and Br2 as final stable products. Our diffraction data at the current signal-to-noise ratio could not provide any evidence for the geminate recombination of the CBr3 and Br radicals to form the Br2CBr-Br isomer or the solvated ion pair, implying that their formation is a minor channel compared with those observed clearly by time-resolved diffraction in this work.

σ/σ* and π/π* Two-center three-electron bonding in complexes formed between charged thiocyanate and X radicals (X=Cl, Br, I and SCN)

Structure, bonding and spectra of various intermediates formed on the reaction of thiocyanate anion (SCN −) with Cl, Br, I and SCN radicals are investigated following ab initio electronic structure theory with 6-311+G(d) set of basis function. Visualization of relevant localized MOs in SCNX − systems (X=Cl, Br, I and SCN) depicts the presence of a σ type two-center three-electron (2c-3e) bond between two hetero atoms and the optical absorption is assigned to σ→σ* transition. However, dimer radical cation, ( SCN ) 2 · + shows the formation of a π type 2c-3e bond between two hetero atoms and the corresponding optical absorption is assigned to π→π* transition.

Single bubble sonochemistry: Decomposition of alkyl bromide and the isomerization reaction of maleic acid

Single bubble cavitation offers an unique opportunity to evaluate the effect of bubble activity in promoting chemical reactions. In this paper we study the isomerization reaction of maleic acid into fumaric acid using an aqueous solution of maleic acid saturated with CH 2Br 2. The Br radicals are generated at the bubble surface and a whitish thread forms. For comparison, the same reaction was conducted in a sonochemical bath. A possible scheme of the reactions activated at bubble surface after the decomposition of organic brominated substances is proposed.

Ab initio study of the magnetic behavior of four dithiadiazolyl radical compounds

Abstract We have studied, by means of ab initio calculations, the magnetic interaction mechanisms in four radical crystals, X –C 6 F 4 –CNSSN ( X = O 2 N, α-NC, β-NC, Br), which has allowed us to explain their different magnetic behaviour (ferromagnetism, antiferromagnetism, paramagnetism, spin frustration, etc.). First, we have identified the magnetic exchange pathways considering those with distances between two atoms of different dithiadiazolyl rings shorter than 7 A and those with an intermolecular distance between an atom of the heterocyclic ring and an atom in a neighbouring radical shorter than 4 A. Second, the calculations have been carried out in the framework of the DFT Broken Symmetry. Following this procedure we have determined the magnitude and the sign of the relevant coupling constants for the X –C 6 F 4 –CNSSN ( X = O 2 N, α-NC, β-NC, Br) radicals. In the cases where the radicals order magnetically, ordering temperatures determined with our ab initio calculations agree very well with the experimental ones. Thus, in the case of the O 2 N derivative ferromagnetic ordering is observed below 1.3 K, in very good agreement with an ordering temperature around 1.6 K predicted from our calculated exchange constants and using a mean field approximation.

The bromine electrode Part II: reaction kinetics at polycrystalline Pt

The kinetics of bromide oxidation and Br3− reduction were studied at polycrystalline Pt electrodes in acidic media. The electrochemical behavior of equimolar Br3− and Br− solutions was investigated, in a concentration range of the electroactive species between 0.1 and 1.0 M. E–log j plots did not exhibit linear segments, most probably because of extensive adsorption of bromine radicals. Further analysis supported the hypothesis of a Volmer–Tafel mechanism, with the chemical recombination step as rate determining. Electrosorption isotherms for Br radicals were found to be of the Frumkin type. The kinetics of Br3− reduction was controlled by the surface dissociation of the Br2 molecules.

The potential influence of iodine-containing compounds on the chemistry of the troposphere in the polar spring. II. Mercury depletion

Simulations of atomic mercury depletion episodes in the polar spring are now based largely on Br2 and Br-atom initiated chemistry. Chlorine is believed to contribute little to the observed depletion. The role, if any, that the presence of iodine compounds play in Hg-atom depletion is unknown at present. The theoretically predicted instability of the HgI species suggests that I-atom reactions with mercury may be an unimportant loss process. However, iodine atoms react rapidly with ozone to develop IO radicals that interact with BrO radicals to enhance Br- and I-atom concentrations, so an indirect influence of iodine compounds on Hg removal might be expected. Computer simulations are described in this study that test this hypothesis using the homogeneous portion of the chemistry of the mercury depletion in the troposphere. Conditions are chosen equivalent to the 1300–1400 h on a clear day (17 March) at the location of Barrow, Alaska (Atmos. Environ. 37 (2003) 4467). Small amounts of reactive trace gases, representative of the Arctic spring, are present initially with typical background levels of Hg (0.24 ppt) and 50 ppb of O3. The simulations show that gaseous atomic mercury depletion in typical Br2 and BrCl mixtures can be enhanced significantly by the presence of small amounts of iodine-containing compounds (I2, CH2I2, CH2IBr, CH2ICl, IBr, and ICl). The major initial product of the possible mercury reactions is HgBr. The subsequent coupling reactions of this species with Br, BrO, Cl, ClO, I, IO, and OH radicals are expected to lead to a variety of reactive gaseous mercury-containing products.

Potential influence of iodine-containing compounds on the chemistry of the troposphere in the polar spring. I. Ozone depletion

Abstract Simulations of atomic mercury depletion episodes in the polar spring are now based largely on Br 2 and Br-atom initiated chemistry. Chlorine is believed to contribute little to the observed depletion. The role, if any, that the presence of iodine compounds play in Hg-atom depletion is unknown at present. The theoretically predicted instability of the HgI species suggests that I-atom reactions with mercury may be an unimportant loss process. However, iodine atoms react rapidly with ozone to develop IO radicals that interact with BrO radicals to enhance Br- and I-atom concentrations, so an indirect influence of iodine compounds on Hg removal might be expected. Computer simulations are described in this study that test this hypothesis using the homogeneous portion of the chemistry of the mercury depletion in the troposphere. Conditions are chosen equivalent to the 1300–1400 h on a clear day (17 March) at the location of Barrow, Alaska (Atmos. Environ. 37 (2003) 4467). Small amounts of reactive trace gases, representative of the Arctic spring, are present initially with typical background levels of Hg (0.24 ppt) and 50 ppb of O 3 . The simulations show that gaseous atomic mercury depletion in typical Br 2 and BrCl mixtures can be enhanced significantly by the presence of small amounts of iodine-containing compounds (I 2 , CH 2 I 2 , CH 2 IBr, CH 2 ICl, IBr, and ICl). The major initial product of the possible mercury reactions is HgBr. The subsequent coupling reactions of this species with Br, BrO, Cl, ClO, I, IO, and OH radicals are expected to lead to a variety of reactive gaseous mercury-containing products.

Relative Reaction Rates of HCHO, HCDO, DCDO, H13CHO, and HCH18O with OH, Cl, Br, and NO3 Radicals

Formaldehyde (HCHO) is a principal intermediate in the photochemical oxidation of hydrocarbons in the troposphere. Isotopic analysis is an important tool for tracing the atmospheric path of gaseous species, and for this purpose, characterization of the isotope effects in the loss processes for formaldehyde is needed. The main loss pathways for formaldehyde in the atmosphere are photolysis and reactions with the radical species of OH, Cl, Br, and NO3. In this study, the kinetic isotope effects in the reactions of five different isotopomers of formaldehyde (HCHO) with OH, Cl, Br, and NO3 radicals are studied in a relative-rate experiment at 298 ± 2 K and 1013 ± 10 mbar. The reaction rates of DCDO, HCDO, H13CHO, and HCH18O with the four radicals are measured relative to H2CO in a smog chamber using long-path FTIR detection. The experimental data are analyzed with a nonlinear least-squares spectral-fitting method using measured high-resolution infrared spectra and cross sections from the HITRAN database. The reaction rates of HCDO and HCH18O with OH and Cl are determined relative to HCHO as kOH+HCHO/kOH+HCDO = 1.28 ± 0.01, kOH+HCHO/kOH+HCH18O = 0.967 ± 0.006, kCl+HCHO/kCl+HCDO = 1.201 ± 0.002, and kCl+HCHO/kCl+HCH18O = 1.08 ± 0.01. The reaction rates of HCDO and HCH18O with Br and NO3 are determined relative to HCHO as kBr+HCHO/kBr+HCDO = 3.27 ± 0.03, kBr+HCHO/kBr+HCH18O = 1.275 ± 0.008, kNO3+HCHO/kNO3+HCDO = 1.78 ± 0.01, and kNO3+HCHO/kNO3+HCH18O = 0.98 ± 0.01. The errors represent 2σ from the statistical analyses, and do not include possible systematic errors.

Characterization of resist-trimming processes by quasi in situ x-ray photoelectron spectroscopy

We have used x-ray photoelectron spectroscopy (XPS) to investigate the resist-patterns’ transformations after exposure to resist trimming plasmas. The influence of the chemistry, the feed gas ratio, the bias power and the pressure have been studied for a Cl2/O2 and a HBr/O2 trim chemistry. An experimental procedure based on the chemical-topography analysis of resist patterns using XPS has been set up to determine the chemical composition and thickness of the reactive layers that are formed both on tops and sidewalls of the resist features during the resist trimming process. The resist modifications obtained by XPS have been correlated with the process performance (trim rate) obtained by SEM observations. In this study, we show that the main difference between HBr/O2 and Cl2/O2 trimming processes is attributed to the difference in reactivity between Br and Cl radicals with the resist during plasma exposure. We succeed in explaining the impact of the plasma parameters (oxygen percentage in the gas phase, bias power, pressure) on the Cl2/O2 trimming process. A decrease in trim rate is well correlated with the formation of a thick and chlorine-rich layer formed on the resist sidewalls.

Photodissociation dynamics of the Kr-HBr cluster: the effect of the rare gas atom substitution.

The ultraviolet photolysis dynamics of Kr-HBr(v=0) is investigated by means of wave packet calculations, focusing on the fragmentation pathway Kr-HBr+ variant Planck's over 2pi omega-->H+Kr-Br. Photolysis is simulated by starting from two different cluster initial states, namely the ground van der Waals (vdW) and an excited vdW bending state, associated with the Kr-H-Br and Kr-Br-H isomers, respectively. The results show that, for the two initial states of the cluster, the Kr-Br product yield is lower than that of Ar-Br radicals found in previous studies on Ar-HBr photolysis. Despite this decrease, the Kr-Br yield is found to be still rather high, in particular for the initial excited vdW state of Kr-HBr(v=0). In addition, the Kr-Br product state distributions exhibit a remarkably higher excitation (mainly rotational) than the corresponding Ar-Br distributions. The lower yield and higher excitation of Kr-Br as compared to Ar-Br, are attributed to a larger share of the energy available for the radical going to internal excitation in the case of the Kr-Br product. The different partition of the energy available for Kr-Br also causes significant deviations in the photolysis behavior of Kr-HBr when compared to that of Ar-HBr, in the case of the initial excited vdW state of both clusters. A common feature of the photodissociation of Kr-HBr and Ar-HBr is the manifestation of quantum interference effects in the Kr-Br and Ar-Br rotational state distributions, in the form of pronounced structures of supernumerary rotational rainbows.

Ab initio MRD-CI Study of the Electronic Spectrum of Tribromomethanol Br3COH and the Photofragmentation along Br–C and C–O Cleavage

Abstract Multi reference configuration interaction calculations are carried out to compute the electronic spectrum of tribromomethanol Br3COH. The first dipole-allowed transitions are computed at 5.0 eV (11 A″ ← X 1 A′) and 5.4 eV (21 A″ ← X 1 A′) followed by three transitions at 5.5 eV (21 A′ ← X 1 A′) and 6.1 eV (31 A′ ← X 1 A′, 31 A″ ← X 1 A′). The largest oscillator strength (f = 0.08) is obtained for the σ → σ* type excitation 31 A″ ← X 1 A′ computed around 6.1 eV. The corresponding triplet states are also given. Five low-lying excited states in the energy range between 4.5 eV and 5.5 eV are found to be highly repulsive for Br–C elongation, leading to Br2CHOH (X 2 A′) and Br (X 2 P), so that tribromomethanol Br3COH is expected to be important for atmospheric chemistry as reservoir of Br radicals. Photodissociation along C–O cleavage resulting in Br3C (X 2 A′) and OH (X 2 Π) has to overcome a barrier of about 0.7 eV because the low-lying excited states 11 A″, 13 A′ and 13 A″ become repulsive only after elongating the C–O bond by about 0.45 Å.

Gas-Phase Reaction of Halon 1301 (CBrF3) with Propane

The nonoxidative gas-phase reaction of Halon 1301 (CBrF3) with propane in a nitrogen bath was investigated using a tubular plug-flow reactor. Experiments were performed at atmospheric pressure, over a range of temperatures from 500 to 700 °C, and at residence times between 0.7 and 4 s. The pyrolysis of propane was also investigated to examine the effect of added Halon 1301 on the pyrolysis reaction. Experimental data suggest that CF3 and possibly Br radicals formed via the thermal cleavage of CBrF3 react with C3H8 and, at higher temperatures, with the decomposition products of C3H8. In addition to HBr, the major products formed during the reaction included CHF3, CH4, C2H4, C3H6, and H2. Minor product species including C2H2, C2H6, C3H4, HF, C2H3F3, C2H2F2, C3H3F3, and C2H3F were detected. Coke formation was also observed on the surface of the reactor.