- Method for preparing perfluorobutyl iodide
-
The invention discloses a method for preparing perfluorobutyl iodide. The method comprises the steps that aluminate ionic liquid is adopted as a solvent and a catalyst, decarboxylation and iodinationof perfluorovaleric acid are conducted under the same condition, and the yield of the perfluorovaleric acid is up to 92% or above. In the process, the step of perfluorovaleric acid alkalization is omitted, conventional liquid alkali is prevented from being used, emission of wastewater and waste salt is reduced, the device cost is reduced, and industrial production is facilitated.
- -
-
Paragraph 0022; 0025-0027; 0032; 0035-0037; 0042; 0045; 0046
(2019/05/08)
-
- PRODUCING SHORT CHAIN PERFLUOROALKYL IODIDES
-
An improved process for producing perfluoroalkyl iodides of formula (I) [in-line-formulae]F(CF2CF2)n—I??(I)[/in-line-formulae] wherein n is an integer from 2 to 3, wherein the improvement comprises contacting at least one perfluoroalkyl iodide of formula (II) and at least one perfluoroalkyl iodide of formula (III) [in-line-formulae]F(CF2CF2)m—I??(II)[/in-line-formulae] [in-line-formulae]F(CF2CF2)p—I??(III)[/in-line-formulae] wherein m is an integer greater than or equal to 3, and p is an integer equal to or lower than 2, at a) a molar ratio of formula (III) to formula (II) of from about 1:1 to about 6:1, b) a residence time of from about 1 to about 9 seconds, and c) a temperature of from about 450° C. to about 495° C.
- -
-
Page/Page column 3
(2011/12/14)
-
- METHOD FOR CONTINUOUS PRODUCTION OF A PERFLUOROALKYL IODIDE TELOMER
-
The present invention relates to a process for continuously producing a perfluoroalkyl iodide represented by the general formula Rf(CF2CF2)nI, wherein Rf is a C1-6 perfluoroalkyl and n is an integer from 1 to 4, the method comprising continuously supplying a perfluoroalkyl iodide as a telogen represented by the general formula RfI, wherein Rf is as defined above, and tetrafluoroethylene as a taxogen to a tubular reactor packed with a metal catalyst comprising a powdery spherical metal or a sintered metal; and conducting telomerization at a temperature of 60 to 160°C under a pressure of 0.1 to 5 MPa (gauge pressure). According to the present invention, medium-chain perfluoroalkyl iodides can be continuously and efficiently produced with little generation of impurities, such as hydrogen-containing organic compounds and the like.
- -
-
Page 5; 6; 7
(2008/06/13)
-
- Highly selective photochemical synthesis of perfluoroalkyl bromides and iodides
-
Highly fluorinated alkyl iodides are conveniently synthesized by telomerization of a fluoroalkyl-iodide, RI, with, e.g., C2F4. Normally, the reaction, often carried out in the liquid phase with a radical initiator, gives products with a broad distribution of molecular weights. In this work, we report a method that obtains selectively products of a desired molecular weight: this method is a photochemically induced reaction in the gas phase; the gas is circulated through a trap or a rectification still which continuously removes the heavier products, whereas the more volatile molecules return to the photoreactor. An analysis by rate equations shows which control parameters are important, and by a suitable choice of these parameters, we obtained a better selectivity for, e.g., C8F17I than previously. This method also works with BrC2F4Br instead of an iodide. In this case, we demonstrated in a small laboratory setup with simple low-pressure Hg lamps (5 × 30 W), a productivity of more than 0.5 kg/day. In the telomerization of CF3Br or HC2F4Br with C2F4 we found, however, a few percent of dibromide side products which are sometimes difficult to separate because of similar boiling points. For this case, it is better to synthesize the iodides instead, and then exchange the I for Br, if desired.
- Zhang,Zhang,Yang,Wang,Fuss,Weizbauer
-
p. 153 - 168
(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)
-
- 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)
-
- 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)
-
- Copper-Induced Telomerization of Tetrafluoroethylene with Fluoroalkyl Iodides
-
In the presence of catalytic amounts of copper, telomerization of tetrafluoroethylene with fluoroalkyl iodides can be carried out at 80-100 deg C.As compared with usual high-temperature (200 deg C) telomerization process, the reaction time required is much shorter.
- Chen, Qing-Yun,Su, De-Bao,Yang, Zhen-Yu,Zhu, Rong-Xian
-
p. 483 - 489
(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)
-
