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Sept. 14, 1954 G. H. CADY ETAL 2,689,254 PROCESS OFFREFARING THE COMPOUND TRIFLUOROMETHYL HYPOFLUORITE Filed Nov. 23, 1949

RE. CNNS.

INVENTOR, ca N Q M2/A A/77aw M2AAoaa. O cN se & B2.4-37% GAO/p6.a A7. Cady 1777OAways Patented Sept. 14, 1954 2,689,254

UNITED STATES PATENT OFFICE 2,689,254 PROCESS OF PREPARNG THE COMPOUND TREFLUOROMETHYL YPOFBLUORE George H. Cady and Karl Brittan Kellogg, Seattie, Wash. Application November 23, 1949, Serial No. 129,076 26 Cairns. (CI. 260-453) 1. 2 Our invention relates to the process of produc nating agent to be used in the production of lubri ing trifluoromethyl hypofluorite. CantS, resins and so forth of high fluorine con For many years, chemists have sought methods tent. for preparing compounds of the type ROF in In connection with forming trifluoromethyl hy which a fluorine atom is linked to an OXygen 5 pOfiuorite from carbon monoxide and fluorine, atom where R is an atom or a radical. Like their We have discovered that the preparation may be chlorine analogs such substances are useful be either with or without a so-called catalyst. We cause of their toxicity and their high chemical find that under certain conditions it is advan reactivity. Also, such compounds are useful as tageous to employ inert diluent gas in connec starting materials to form other compounds. 0. tion with the Substances to be reacted upon in In the past only a few Such compounds Con the production of the product trifluoronethyl hy taining fluorine have been produced, Such as pOfluorite but may be omitted. These inert dil oxygen fluoride (OF2), fuorine nitrate (FNO3), luent gases may be nitrogen, argon, helium, and and fluorine perchlorate (FClO4) which contain hydrogen fluoride. We have discovered that under an O-F group. The latter two compounds are certain conditions it is advantageous to employ dangerous to use because they are highly explo a heat resistant porous mass which may operate SiVe. as Or after the manner of a catalyst or as a de We have found that trifluoromethyl hypofiuo Vice Which prevents explosions of the reacting rite (CF3OF) can be produced in high yield by gases. The bringing together of the gases fluorine the action of fluorine upon a variety of carbon : and Carbon monoxide develops a reaction heat of compounds having a molecular structure in which Such intensity that care must be used to prevent an oxygen aton is directly linked to a carbon the ignition of the apparatus. By having the atom. As an outstanding exemplification of our reaction of the gases take place in the presence discovery and to point out a specific compound Of the porous mass, said porous mass functions at this point, we have found, among others, that to distribute the reaction over a large volume in carbon monoxide is particularly efficient in pro contrast to a localized volume, and also to with viding a high yield of trifiuoromethyl hypofiuorite. draw the heat from the zone of reaction. By employing carbon monoxide to react with the The degree of diluting with the inert gas is not fiuorine, the reaction is characterized by the Small a critical feature. According to our experience, annount of fuorine consumed. We have found 3 Substantially equal volumes give satisfactory re if the carbon aton is also additionally linked with Sults. It functions as a method of controlling the Other Carbon attorns or other attorns other than heat liberated by the reaction. The diluent may the fiuorine, then these bonds will be broken and be omitted entirely. the formation of trifiuoromethyl hypofluorite Will The apparatus employed is illustrated in the result. 3 5 following drawings, throughout which drawings The term 'reacting' is used herein to connote iike reference numerals indicate like parts: the chemical change with or without, a flame, the Figure 1 is a schematic view of the arrange change occurring either in or not in the presence ment of the apparatus used in one process herein of a catalyst. "Burning' is used to connote react Set forth of producing trifluoromethyl hypofluo ing With the formation of a flaine with or with 40 rite; out a catalyst. "Directly reacting' is used to coin Fig. 2 is a view in vertical section of the reac note that the reaction took place in the absence tion chamber or vessel; Of an added catalyst. Fig. 3 is a View in vertical section of the reac Among the possible uses for the compound pro tion chamber of the apparatus used in another duced by our nethod are the following: The com proceSS herein Set forth of producing trifluoro pound itself may be employed as a toxic gas to methyl hypofluorite; and kill insectS or other living things or other animal Fig. 4 is a View in Wertical Section of a modi ife. The coil pound itself inlay be used as an fied form of the reaction chamber of Fig. 3. oxidizing agent to Support the combustion of For purpose of clearness and definiteness of fuels in engines. The compound may be used: disclosure, the apparatus is set forth wherein the (d) as a reagent to be cornbilled with insat compouild employed is carbon monoxide. The lated Organic Substances to form other substances reaction Wessel or chamber 2 has inlet conduit containing fluorine; (b) as a reagent to replace 2 for the admission of carbon monoxide from the hydrogen atoms in organic molecules with radi Supply cylinder 22 with its control valve 23 and Calls of high fluorine content; and (c) as a fluori 5 5 flow meter 26. If a diluent such as nitrogen is 2,689,254 3. 4 employed, it may be introduced and intermixed the formation of overheated localized zones dur With the carbon monoxide through conduit 25 ing the reacting of the fluorine. With its flow meter 26 and control valve 2 from It has been found that fluorinating agents, nitrogen supply cylinder 28. Such as silver difluoride and cobalt trifluoride, Similar connections are provided for the admis 5 When used alone fail to produce the trifluoro Sion of fluorine (F) to the reaction chamber 20 nethyl hypofluorite with compounds containing Which also has inlet conduit 29 having flow meter carbon linked directly to oxygen. The direct 3 and control valve 3 communicating with Sup action of fluorine is required. ply cylinder 32. If a diluent gas, as nitrogen, is For directly reacting fluorine with a carbon employed, it may be introduced and intermixed O Compound having an atom of carbon directly With the fluorine through conduit 33 with its flow linked to an OXygen atom, a reaction vessel 50, meter 34 and control valve 35 from supply cylin Fig. 3, having the carbon compound, as for ex der 36. ample carbon monoxide, inlet conduit 5 in its Reactor chamber 20 may be constructed with lower portion, and likewise a fluorine conduit 52 a temperature control or heating mechanism com in the lower portion and lead off product conduit prising an electrical insulation covering 3 for 53 may be employed. The position of the inlet the chamber or vessel 20 insulating the heating conduits 5 and 52 may be located in the upper means of Nichrome ribbon 38 having lead wires portion of the reaction vessel. The material used 39 and 40 for the upper portion of the chamber in the Construction of the reaction vessel 50 and 2) and Nichrome ribbon 4 With lead wires 42 20 the ConduitS 5 and 52 should be resistant to and 43 for the lower portion of the chamber 20. attack by fluorine and the material may be, for A heat insulation coating 44 is preferably pro example, Copper or nickel. vided for the vessel 29 as well as temperature wells The rate of production preferably may be in 45 and 46. Creased by employing a heat transfer mechanism Outlet conduit 47 for the products produced by 25 55 (as a common Water jacket) about the reaction the reaction extends to trap 48 which may be Vessel 56, Fig. 4, particularly about that portion cooled by being immersed in liquid oxygen. To of the reaction vessel where reaction is initially remove any hydrogen fluoride present the prod taking place. Also, preferably a heat transfer lucts being removed by outlet conduit 47 may be mechanism 57 (as a water jacket) may be pro treated according to common practice to a sodium 30 Vided for the Carbon nonOXide inlet tube 58. fluoride trap before the gaseous products reach Of course, if desired, a diluent may be em the trap 48. ployed alone as a means in controlling, or as a A catalyst comprising a ribbon 49 of copper Cooperating controlling means, of the reaction. coated with silver may be employed in vessel 20. The catalyst is prepared for use by exposing it to Methods of production fluorine which converts the silver to fluorides of 1. Fluorine, flowing at a rate of about ten liters Silver. per hour WaS mixed with nitrogen flowing at six The reaction vessel 20 consists of a copper tube liters per hour and the mixture was passed into 7.5 cm. inside diameter and 90 cm. length. It the reaction vessel near one end. Carbon mon may be packed tightly with 4500 g. of copper 40 Oxide Was mixed With One-and-a-half times its ribbon functioning as a catalyst 49 of 0.035 cm. Volune of nitrogen and the mixture was passed Width and 0.008 cm. thickness having a total sur into the reaction vessel at a rate of five liters per face area of 150,000 sq. cm. In the preparation hour. The function of nitrogen was to lessen the of the catalyst 100 g. of silver is preferably de intensity of the reaction. The nitrogen pre posited on the surface of the ribbon by displace Wents the localization of the reaction and thereby ment from a solution containing Ag (CN)2 ion. reduces the chance that the temperature may Fluorine gas is later used to convert the silver reach a degree where the catalyst night ignite to the difluoride. The reaction vessel is built in in the fluorine. The two streams of gas entered Such a way that its temperature can be controlled from Opposite Sides of the cylindrical reactor. by regulating the flow of electricity through two 50 GaSeOllS products together with unreacted Separate Sections of Nichrome ribbon 38 and 4 fuorine and nitrogen left the reactor through an used for electrical heating. When the system is outlet located at the end remote from the inlets. in Operation, a temperature between 160 and 180 This mixture of gases passed through a condenser degrees C. is maintained. This system may be cooled by liquid oxygen. From the mixture of used at temperatures up to the ignition point of Substances collected in the condenser, trifluoro Copper in fluorine (well above 300 degrees C.) methyl hypofluorite was separated by fractional and down to the temperature which is main distillation. Its volume, when in the gaseous tained by the heat of reaction of the materials. State, was approximately seven tenths as great The Size of the equipment and the nature of the as the volume of carbon monoxide used in its catalyst are not critical excepting for these quali 60 production. fications: It is necessary to use a reaction vessel It has long been known that carbon monoxide of Sufficient Size to permit the heat of the re (CO) plus fluorine (F) will combine to form car action to be dissipated at temperature lower than bonyl fluoride according to the equation: the ignition point of the catalyst. Only small CO--F2=COF2. Applicants have discovered upon free Spaces should be left between different por bringing together the carbon monoxide and tions of the Catalyst in order that violent ex fluorine with the fluorine present in the propor plosions Within the reacting gases may be pre tion of more than one mole of fluorine to each vented. When a compound in which hydrogen mole of carbon monoxide under the conditions set atoms are attached to carbon atoms is being forth herein, then the reaction takes place pro fluorinated, the temperature of the catalyst ducing trifluoromethyl hypofluorite according to should be at about 125 degrees C. or higher to the equation of: CO-2F2=CF3OF. Let it be prevent the formation of a polymer of tar-like particularly noted that the large excess of character when the catalyst loses its activity. fluorine to the carbon monoxide of the example The catalyst should be characterized by high heat is not necessary for the production of the tri Conductivity and heat capacity so as to prevent fluoromethyl hypofluorite but the fluorine pref 2,689,254 5 6 erably should be present slightly in excess of two similar to that of fluorine or oxygen fluoride moles per one mole of the carbon monoxide. (OF2). It reacts with aqueous solutions of sodi 2. Streams of carbonyl fluoride (COF2) and of unn hydroxide and with many other materials. fluorine, both diluted with nitrogen, were caused Care must be used in Working With fluorine, to mix in the reactor 20 in the presence of a cata and particularly with the Substances set forth lyst 49 at about 170 degrees C. and the products herein Special care must be taken to avoid explo were removed as described above. A high yield Sions. This may be accomplished by causing the of trifluoromethyl hypofluorite was obtained. reaction to take place in the presence of a porous 3. One and one - third moles of ethanol maSS as provided by the catalyst herein. Set forth, (C2H5OH) vapor diluted with ten times its vol O or by diluting the gases with inert gases, or by lume of nitrogen was caused to react with 12.3 causing the reaction to take place rapidly as the moles of fluorine. The reactor with the so-called Substance or compound mixes with the fluorine catalyst was used at a temperature of 175 de as by burning. grees C. The process took place over a period of We cairn: 43 hours. An extended period of time was em 1. The process of producing the compound, tri ployed to avoid undue rise of temperature in the fluoromethyl hypofluorite, comprising directly reactor and thereby ignition of the equipment. reacting a compound having a molecular struc Products of the reaction were trifluoromethyl ture in which an oxygen atom is directly linked hypofluorite, carbon tetrafluoride, hydrogen flu to a carbon atom, with fluorine, the latter being Oride, and hexafluoroethane. Oxygen fluoride present for the reaction in an amount in excess was also present, but it is not known whether it stoichiometrically calculated as required for the came from the reaction, since it may have been production of carbonyl fluoride and the complete an inpurity in the fluorine. fluorination of the parts of the molecule not di 4. Tertiary butyl alcohol was fluorinated in the rectly linked to oxygen. Sane manner as that used with ethanol. Among 2. The process of producing the compound, tri the products were trifluoromethyl hypofluorite, fluoromethyl hypofluorite, comprising burning a carbon tetrafluoride and octafluoropropane and compound having a molecular structure in which decafuorobutane. an oxygen atom is directly linked to a carbon 5. A 0.52 mole sample of ethylene glycol was atom, with fluorine, the latter being present for fluorinated in the catalytic reaction vessel. 20 30 the reaction in an aimount in excess Stoichiome using 6.5 moles of fluorine. The reaction took trically calculated as required for the production place over a period of 56 hours during which time of carbonyl fluoride and the complete fluorina the reactor was kept at about 175 degrees C. The tion of the parts of the molecule not directly reacting gases were diluted with nitrogen. Prod linked to oxygen. ucts of the reaction were carbon dioxide, carbonyl 3. The process of producing the compound, tri fluoride, hydrogen fluoride and trifluoromethyl fluoromethyl hypofluorite, comprising directly re hypofluorite. Approximately 0.8 mole of the lat acting by bringing together a current of a con ter was obtained. pound having a molecular structure in which an 6. Using the catalytic reaction vessel 20 at Oxygen aton is directly linked to a carbon aton about 150 degrees C. a. 0.55 mole sample of cyclo 40 and a current of fluorine, the latter being present hexanone was caused to react with an excess of for the reaction in an amount in excess stoir fluorine in the presence of nitrogen acting as a chiometrically calculated as required for the pro diluent. Among the products were 1.5 liters of duction of carbonyl fluoride and the complete gaSeOuS Carbon tetrafiloride and 0.44 holes of fluorination of the parts of the molecule not di trifluoronethyl hypofluorite. Much dodeca rectly linked to oxygen; and maintaining the rate fluoropentane Was also obtained. of flow of said currents at a rate which prevents 7. Formaldehyde may be fluorinated in the the heating of the reaction vessel to the ignition Same manner as that used for carbon monoxide. point of Said vessel. The fluorination by burning with fluorine of 4. The process of producing the compound, a Compound having a molecular structure in trifluoromethyl hypofluorite, comprising burning which an oxygen atom is directly linked to a car. a gurrent of a cornpound having a molecular bon atom Was done in the apparatus as shown Structure in which an oxygen aton is directly in Fig. 3. The carbon monoxide was introduced linked to a carbon aton and a current of fluorine, at the rate of about one liter per hour and the the latter being present for the reaction in an fluorine at the rate of about four liters per hour'. 5 5 anount in excess stoichiometrically calculated as These gases entered the reaction vessel 59 cold required for the production of carbonyl fluoride but as soon as the carbon monoxide came into and the complete fiuorination of the parts of the contact with the fluorine, immediate reaction molecule not directly linked to oxygen; and main began and a flame 54 appeared at the end of the taining the rate of flow of said currents at a rate inlet tube 5, i. e., the carbon monoxide was 60 which prevents the heating of the reaction ves Caused to react in an atmosphere of fluorine. Sel to the ignition point of Said vessel. The yield of the trifluoromethyl hypofluorite 5. The progeSS Of producing the compound, Was about 96 percent of the theoretical amount trifluoronethyl hypofluorite, comprising directly obtainable from the carbon monoxide employed. reacting a compound having a molecular struc No diluent inert gas was employed and no cata ture in which an oxygen aton is directly linked lyst. to a carbon aton, the said compound being mixed We now have discovered that the function of with a diluent inert gas, with fluorine mixed with the catalyst is primarily to aid in controlling the a diluent inert gas, the said fluorine being present rate of the reaction, dissipation of the heat for the reaction in an annount in excess stoi liberated, and prevention of the production of chiometrically calculated as required for the pro objectionable by-products. duction of carbonyl fluoride and the complete The trifluoromethyl hypofluorite produced sy fluorination of the parts of the rinolecule not di the methods herein set forth boils at about -94.2 rectly linked to oxygen. degrees C. and is stable even above 450 degrees C. 6. The process of producing the compound, tri It is a strong oxidizing agent and has an odor fluoromethyl hypofluorite, comprising burning a 2,689,254 7 8 compound having a molecular structure in which mixed with a diluent inert gas, the fluorine being an oxygen atom is directly linked to a carbon present for the reaction in the proportion of more atom, said compound being mixed with a diluent than one mole per mole of the carbon monoxide inert gas, with fluorine mixed with a diluent in the presence of a catalyst of high heat Con inert gas, the Said fluorine being present for the ductivity at a temperature of 125 degrees to 300 reaction in an amount in excess Stoichiometri degrees C.; and maintaining the rate of flow of cally calculated as required for the production of said currents at a rate which prevents the heat Carbonyl fluoride and the complete fluorination ing of the reaction vessel to the ignition point of the parts of the molecule not directly linked Of said vessel. to Oxygen. O 15. The process of producing the compound, 7. The process of producing the compound, tri trifluoromethyl hypofluorite, comprising reacting fluoromethyl hypofluorite, comprising reacting carbony fluoride (COF2) with fluorine. carbon monoxide with fluorine, the latter being 16. The process of producing the compound, present for the reaction in the proportion of more trifluoromethyl hypofluorite, comprising burning than One mole per mole of the carbon monoxide. 5 carbonyl fluoride (COF2) with fluorine. 8. The process of producing the compound, tri 17. The process of producing the compound, fluoromethyl hypofluorite, comprising bringing trifluoromethyl hypofluorite, comprising bringing together a current of carbon monoxide with a together a current of carbonyl fluoride with a current of fluorine, the latter being present for current of fuorine; and maintaining the rate of the reaction in the proportion of more than one 20 flow of Said currents at a rate which prevents the mole per mole of the carbon monoxide; and main heating of the reaction Wessel to the ignition taining the rate of flow of Said currents at a rate point of Said vessel. which prevents the heating of the reaction ves 18. The process of producing the compound, Sel to the ignition point of Said vessel. trifluoromethyl hypofluorite, comprising bringing 9. The process of producing the compound, tri 25 together a current of carbonyl fluoride with a fluoromethyl hypofluorite, comprising bringing current of fluorine in the presence of a Catalyst together a current of carbon monoxide with a of high heat conductivity. current of fluorine, the latter being present for 9. The process of producing the Compound, the reaction in the proportion of more than one trifiuoromethyl hypofluorite, comprising bring mole pel. Inole of the Carbon monoxide in the 30 ing together a current of carbonyl fluoride With a presence of a catalyst of high heat conductivity. current of fluorine in the presence of a catalyst 10. The process of producing the compound, of high heat conductivity; and maintaining the trifluoromethyl hypofluorite, comprising bringing rate of flow of Said currents at a rate which pre together a current of carbon monoxide with a vents the heating of the reaction vessel to the current of fluorine, the latter being present for 35 ignition point of Said Wessel. the reaction in the proportion of more than One 20. The process of producing the Compound, mole per mole of the carbon monoxide in the trifluoromethyl hypofluorite, comprising react presence of a catalyst of high heat conductivity; ing carbonyl fluoride mixed with a diluent inert and maintaining the rate of flow of said currents, gas with fluorine mixed With a diluent inert gaS. at a rate Which prevents the heating of the reac 40 21. The process of producing the compound, tion Wessel to the ignition point of Said vessel. trifluoromethyl hypofluorite, comprising bringing 11. The process of producing the compound, together a current of carbonyl fluoride mixed with trifluoromethyl hypofluorite, comprising bring a diluent inert gas with a current of fluorine ing together a current of carbon monoxide with mixed. With a diluent inert gas in the presence of a current of fluorine, the latter being present for 45 a catalyst of high heat conductivity; and main the reaction in the proportion of more than one taining the rate of flow of said currents at a rate mole per mole of the Carbon monoxide in the which prevents the heating of the reaction ves presence of a catalyst of high heat conductivity sel to the ignition point of Said vessel. at a temperature of 125 degrees to 300 degrees 22. The process of producing the compound, C.; and maintaining the rate of flow of Said cur 50 trifluoromethyl hypofluorite, comprising bring rents at a rate which prevents the heating of the ing together a current of carbonyl fuoride mixed eaction Wessel to the ignition point of Said vessel. With a diluent inert gas with a current of fluorine 12. The process of producing the compound, mixed with a diluent inert gas in the presence trifluoromethyl hypofluorite, comprising reacting of a catalyst of high heat conductivity at a tem carbon monoxide mixed with a diluent inert gas perature of 125 degrees to 300 degrees C.; and with fluorine mixed with a diluent inert gas, the maintaining the rate of flow of Said currents at fluorine being present for the reaction in the pro a rate which prevents the heating of the reaction portion of more than One mole per mole of the Wessel to the ignition point of Said vessel. Carbon monoxide. 23. The proceSS of producing the compound, 13. The process of producing the compound, 60 trifluoromethyl hypofluorite, comprising reacting trifluoromethyl hypofluorite, comprising bring ethanol with fluorine, the latter being present for ing together a current of carbon monoxide mixed the reaction in the proportion of more than six With a diluent inert gas With a current of fluorine Inoles per mole of ethanol. mixed with a diluent inert gas, the fluorine being 24. The proceSS of producing the compound, present for the reaction in the proportion of more trifluoromethyl hypofluorite, comprising reacting than one mole per mole of the carbon monoxide ethylene glycol with fiuorine, the latter being in the presence of a catalyst of high heat con present for the reaction in a proportion of more ductivity; and maintaining the rate of flow of than five moles per mole of ethylene glycol. Said currents at a rate which prevents the heat 25. The process of producing the compound, ing of the reaction vessel to the ignition point 70 trifluoromethyl hypofluorite, comprising reacting of said vessel. formaldehyde with fluorine, the latter being pres 14. The process of producing the compound, ent for the reaction in a proportion of more than trifluoromethyl hypofluorite, comprising bringing two moles of fluorine per mole of formaldehyde. together a current of carbon monoxide mixed 26. The process of producing the compound, with a diluent inert gas with a current of fluorine 75 trifluoromethyl hypofluorite, comprising burning 2,689,254 10 a current of carbon monoxide with a current of OTHER REFERENCES fluorine, the latter being present for the reaction Humiston et al.: J. Phys. Chem., vol. 23, pp. in the proportion of more than one mole per mole 572-7 (1919). of the carbon monoxide. Fukuhara, et al.: J. Am. Chem. Soc., vol. 63, pp. 88-91 (1941). References Cited in the file of this patent Kellogg et al.: Abstracts, New York Meeting, UNITED STATES PATENTS Am. Chem. Soc., page 24J (September 1947). Number Name Date Miller et al.: J. An. Chen. Soc., Vol. 70, page 2,013,035 Daudt ------Sept. 2, 1935 2602 (1948) . 2,447,717 Simons ------Aug. 24, 1948