- Preparation of trifluoroiodomethane via vapour-phase catalytic reaction between pentafluoroethane and iodine
-
A new route for preparing C33I has been developed via a reaction between C2HF5 and I2. The influence of reaction temperature and active components of the catalysts on the amount of C33I was investigated. The result suggests that the selectivity of the C33I can be controlled by reaction conditions and active component of catalyst. The process for the formation of C33I and by-products is also discussed.
- Mao, Aiqin,Wang, Hua,Tan, Linhua,Nin, Xiangyang,Pan, Renming
-
p. 4640 - 4642
(2013/07/19)
-
- Preparation of trifluoroiodomethane via vapor-phase catalytic reaction between hexafluoropropylene oxide and iodine
-
Based on our previous investigation on the reaction mechanism to produce difluorocarbene and subsequent CF3I starting with CHF3 and I2, a new route for preparing CF3I at a relative low temperature, 200 °C, has b
- Yang, Guang-Cheng,Jia, Xiao-Qing,Pan, Ren-Ming,Quan, Heng-Dao
-
experimental part
p. 985 - 988
(2010/02/28)
-
- Investigation of CF2 carbene on the surface of activated charcoal in the synthesis of trifluoroiodomethane via vapor-phase catalytic reaction
-
This paper investigates the synthetic mechanism of trifluoroiodomethane (CF3I) in the reaction of trifluoromethane and iodine via vapor-phase catalytic reaction. It is suggested that CF2 carbene is the key intermediate and is formed in the pyrolysis process of CHF3 at high temperature. However, in pyrolysis of CHF3 under activated charcoal (AC) existing conditions, no C2F4 was detected. H2 and 2-methyl-2-butene could not trap the CF2 carbene. When treating the remained compounds on the used AC with H2, CH4 is formed on the process. It is proposed that CF2 carbene combines with AC strongly and transfers into CF3 radical on heat. In addition, it is found that the AC is not only the catalyst supporter to form CF3I, but also a co-catalyst to promote the formation of CF2 carbene and CF3 radical.
- Yang, Guang-Cheng,Lei, Shi,Pan, Ren-Ming,Quan, Heng-Dao
-
experimental part
p. 231 - 235
(2009/08/07)
-
- METHOD FOR PRETREATING AND REGENERATING CATALYSTS USED IN A PROCESS FOR MAKING FLUOROIODOALKANES
-
A process for the preparation of a fluoroiodoalkane represented by the structural formula CF3(CF2)n—I, wherein n is 0 or 1. The process has the step of reacting a source of iodine with a compound represented by the structural formula CF3(CF2)n—Y, wherein Y is selected from H, Cl, Br and COOH and wherein n is 0 or 1. The reaction is carried out at a temperature from about 100° C. to about 750° C. and at a pressure from about 0.001 to about 100 atm for a contact time from about 0.001 second to about 300 hours in the presence a catalyst. The catalyst is subject to one or both of the following: (a) treating the catalyst prior to the reaction via contact with a gas selected from the group consisting of hydrogen fluoride, trifluoromethane, hydrogen, hydrogen iodide, iodine, fluorine, and oxygen, wherein the contact is carried out at a temperature and for a contact time sufficient to reduce the length of the induction period of the catalyst; and (b) treating the catalyst after the reaction via contact with a gas selected from the group consisting of hydrogen fluoride, hydrogen, fluorine, oxygen, or air at a temperature and for a contact time sufficient to regenerate the catalyst.
- -
-
Page/Page column 3-4
(2009/06/27)
-
- Catalyst for the synthesis of CF3I and CF3CF2I
-
A process for the preparation of a fluoroiodoalkane compound represented by the formula: CF3(CF2)n—Y, wherein n is 0 or 1. The process includes contacting A, B and C. A is represented by the formula: CF3(CF2)n—Y, wherein n is 0 or 1, and Y is selected from the group consisting of: H, Cl, Br, and COOH. B is a source of iodine, and C is a catalyst containing elements with d1s1 configuration and lanthanide elements. The process occurs at a temperature, and for a contact time, sufficient to produce the fluoroiodoalkane compound.
- -
-
Page/Page column 2
(2008/12/08)
-
- Surface Chemistry and Radiation Chemistry of Trifluoroiodomethane (CF 3I) on Mo(110)
-
The surface-induced and electron-induced chemistry of trifluoroiodomethane (CF3I), a potential replacement for chlorofluorocarbons (CFCs) and chlorofluorobromocarbons (halons), were investigated under ultrahigh vacuum conditions (p a?? 1 a?? 10-10 Torr) on Mo(110). Results of temperature-programmed desorption (TPD) experiments indicate that dissociative adsorption of CF3I leads only to nonselective decomposition on Mo(110), in contrast to reactions of CF3I on other metal surfaces. Desorption of CF3 radicals and atomic iodine was detected mass spectrometrically during low-energy (10-100 eV) electron irradiation of four monolayer thick films of CF3I condensed at 100 K. Results of postirradiation temperature-programmed desorption experiments were used to identify CF2I2, C2F5I, C 2F6, C2F4I2, and CFI3 as electron-induced reaction products of CF3I. Except for CFI 3, all of these electron-induced reaction products of CF3I have been previously identified in ?3-radiolysis studies, supporting our earlier claim that temperature-programmed desorption experiments conducted following low-energy electron irradiation of multilayer thin films provide an effective method to investigate the effects of high-energy radiation, including radical-radical reactions.
- Nakayama, Nozomi,Ferrenz, Elizabeth E.,Ostling, Denise R.,Nichols, Andrea S.,Faulk, Janelle F.,Arumainayagam, Christopher R.
-
p. 4080 - 4085
(2007/10/03)
-
- Kinetics of the photochemical reaction of C, Ind. Eng. Chem. Process Des. 2F5I and C4F9I with C2F4
-
Although the formal insertion of C2F4 into the CI bond of iodides is a chain reaction, we found quantum yields clearly below 1. We show that this is due to an inhibition reaction: the ,Ind. Eng. Chem. Process Des.ery rapid reaction of the radicals with molecular iodine, which accumulates during the reaction in amounts equal to the radical dimers. The corresponding kinetic model quantitati,Ind. Eng. Chem. Process Des.ely describes the quantum yields and product distributions, if we assume for the rate constants kn for the addition of the F(C, Ind. Eng. Chem. Process Des. 2F4)n radicals to C2F4 (in 107 cm3 mol-1 s-1 at 373 and 303 K, respecti,Ind. Eng. Chem. Process Des.ely): k1 = 19 and 3.6, k2 = 8.0 and 1.9, k3 = 1.6 (303 K). ,Ind. Eng. Chem. Process Des.CH ,Ind. Eng. Chem. Process Des.erlagsgesellschaft mbH, 1997.
- Linyang, Zhang,Xiaoyu, Zhang,Wcihua, Yang,Xudong, Lou,Fuss
-
p. 1158 - 1164
(2007/10/03)
-
- Lewis acid catalyzed conjugated iodofluorination of fluoroolefins
-
A process for the preparation of perfluoroalkyl iodides, especially perfluoroethyl iodide, by reaction of perfluorinated compounds which contain a carbon carbon double bond with ICl in HF solvent in the presence of Lewis acid catalysts. The compounds are used as telogens for the telomerization of tetrafluoroethylene to long-chain perfluoroalkyl iodides.
- -
-
-
- Facile conversion of perfluoroacyl fluorides into other acyl halides
-
Nine perfluoroacyl fluorides underwent halogen exchange when treated with anhydrous lithium halides to give acyl chlorides, bromides and iodides in high yields. The temperature dependence of this reaction is described. In the reaction with perfluorodiacyl fluoride, the diacyl halides possessing different acyl halide-groups were also produced. Of the alkaline metal salts used halogen exchange was successful only with lithium salts because of the interaction between lithium and fluorine.
- Fukaya, Haruhiko,Matsumoto, Tomonori,Hayashi, Eiji,Hayakawa, Yoshio,Abe, Takashi
-
p. 915 - 920
(2007/10/03)
-
- RELATIONSHIPS IN THE IODOFLUORINATION OF FLUOROOLEFINS IN THE IODINE-IODINE PENTAFLUORIDE-METAL FLUORIDE SYSTEM
-
On the basis of the results from investigation of the reaction of fluoroolefins with the components of the iodine-iodine pentafluoride-metal fluoride iodofluorinating system and kinetic and spectroscopic investigations a mechanism is proposed for the iodofluorination of fluoroolefins as the conjugate addition of iodine and fluorine with initial electrophilic attack on the multiple bond by the I2+ cation.The role of mass exchange during synthesis in a flow-type system is noted.
- Morozov, A. V.,Maksimov, B. N.
-
p. 1224 - 1229
(2007/10/03)
-
- REACTIONS OF TeF5OCl WITH FLUOROCARBON IODIDES AND SYNTHESIS OF CF3OTeF5
-
The low temperature reaction of TeF5OCl with the fluorocarbon iodides, CF3I, C2F5I, n-C3F7I, and i-C3F7I results in the formation of RfI(OTeF5)2 adducts.Except for the trifluoromethyl derivative these are stable, colorless compounds.The trifluoromethyl adduct decomposes above -78 deg C to give the previously unknown CF3OTeF5.The perfluoroethyl and n-propyl adducts decompose at 120 deg C or under UV radiation giving C2F5OTeF5 and n-C3F7OTeF5, respectively.These reactions constitute a new synthesis of primary RfOTeF5 compounds.Attempts to extend this synthesis to secondary fluorocarbon iodides were unsuccessful.
- Schack, Carl J.,Christe, Karl O.
-
-
- CO2 Laser Induced Chain Reaction of C2F4 + CF3I
-
A pulsed CO2 laser was used to induce the telomerization of CF3I with C2F4 in gas phase.This is an exothermic radical chain reaction, producing CF3(CF2)nI with low n.A problem, previously considered unresolvable, exists at low pressure: Good primary quantum yield is in conflict with long chain length; for kinetic reasons the chain length is short, if initially a high yield of radicals is generated by IR multiphoton dissociation.Radical dimers dominate in this case.To avoid this undesired direction of the reaction, we applied a novel method: At high pressure theradicals are generated with delay only, so that their instantaneous concentration is always small.At 3 bar we attained quantum yields of 0.2 for the desired iodides, with selectivity of 80percent.This good selectivity is a consequence of the second-order termination, according to our analysis.The quantum yield is 100 times larger than previously reported for a CO2 laser induced reaction.It can be raised even more, if the exothermicity is used for further propagation.We only came close to this ignition threshold.With more laser energy in longer pulses, it could be reached.
- Mengxiong, Gong,Fuss, W.,Kompa, K. L.
-
p. 6332 - 6337
(2007/10/02)
-
- THERMOLYSIS AND UV-PHOTOLYSIS OF PERFLUORINATED IODO-ALKANES AND IODO-OXAALKANES: THERE IS A PREFERRED REACTION CHANNEL
-
The thermal stability of perfluorinated iodides depends on their structure and decreases in the order of RFCF2CF2I>RFCF2CF(CF3)I>RFOCF(CF3)I=RFCF2C(CF3)2I.The major decomposition path consists of the elimination of an unsaturated compound (CF2=CF2, CF2=CF-CF3, O=CF-CF3, CF2=C(CF3)2, respectively) with concomitant formation of RFI.The highest selectivities were found for tertiary iodides and 2-iodo-3-oxaalkanes, whose decomposition is virtually irreversible.UV-photolysis of the iodo-compounds gave the same products as the thermolysis reactions.
- Probst, Anton,Werner, Konrad von
-
p. 163 - 173
(2007/10/02)
-
- Convenient Synthesis of N-Containing Perfluoroalkyl Iodides
-
Some new nitrogen-containing perfluoroalkyl iodides were synthesized directly by the reaction of corresponding perfluoroacid fluorides with lithium iodide in high yield.
- Fukaya, Haruhiko,Abe, Takashi,Hayashi, Eiji
-
p. 813 - 814
(2007/10/02)
-
- SYNTHESIS AND CHEMISTRY OF PERFLUORO-2-IODO-2-METHYL-ALKANES
-
Two novel perfluoro-tert-alkyl iodides CF3(CF2)n+1C(CF3)2I have been obtained from F-alkenes CF3(CF2)n-CF=C(CF3)2 (n = 0 and 1) by formal additions of iodine fluoride; these required substantial alterations of known procedures.The F-tert-alkyl iodides are the most reactive alkyl halides known so far, and they are also very toxic.The following types of reactions have been studied: (a) Nucleophilic attack of anions at the iodine, leading to F-alkenes, (b) elimination of iodine fluoride, caused by metals or metal complexes, (c) pyrolysis, to give very selectively F-isobutene and n-perfluoroalkyl iodides, (d) photolysis, and (e) thermally induced insertions into the carbon-iodine bond.Screening results on the inhalation toxicity of the iodides and of some other fluoro-compounds are also reported.
- Probst, A.,Raab, K.,Ulm, K.,Werner, K. von
-
p. 223 - 246
(2007/10/02)
-
- THERMOLYSE DES HALOGENURES DE PERFLUOROALCANESULFONYLE
-
Perfluoroalkanesulfonyl chlorides FSO2Cl; RF= CF3, C2F5, C4F9>, decompose thermally to give the corresponding perfluoroalkyl chlorides with evolution of SO2.The latter retards the reaction, but it is catalysed by copper which also inhibits the SO2 effect. 2-methyl-2-nitrosopropane traps the perfluoroalkyl free radicals.In the presence of a perfluoroalkyl iodide FI; R'not equal RF>, other products, RFI and RFCl, are obtained.A free radical chain-mechanism is then suggested.On the other hand, perfluorobutanesulfonyl fluoride is very stable thermally.
- Oudrhiri-Hassani, M.,Brunel, D.,Germain, A.,Commeyras, A.
-
p. 491 - 504
(2007/10/02)
-
