US3113145A - Fluorinated mono-olefin carbonyl compounds of group vb-viii transition metals - Google Patents

Description

United States Patent 3,113,145 FLUQRINATED MONO-OLEFHN CARBQNYL CGM- POUNDS OF GROUP VB-VIII TRANSITIGN METALS Geoffrey Wilkinson, London, England, assignor to Ethyl Corporation, New York, N.Y., a corporation of Virginia No Drawing. Filed July 20, 1960, Ser. No. 44,027 7 Claims. (01. 260-439) This invention relates to novel organometallic compounds and their mode of preparation. More specifically, this invention relates to fluorinated monoolefin-transition metal-carbonyl compounds of the group VB-VIII metals. The applicable metals are those which form simple carbonyls such as vanadium hexacarbonyl, molybdenum hexacarbonyl, tungsten hexacarbonyl, dimanganese decacarbonyl, dirhenium decacarbonyl, iron pentacarbonyl, triiron dodecacarbonyl, trirut-henium dodecaoarbonyl, triosmium dodecacarbonyl, dicobalt octacarbonyl, nickel tetracarbonyl and the like.

Although many compounds are reported in the prior art in which polyolefins are bonded to a transition metal, all prior efforts to prepare compounds in which a monoolefin is bonded to the metal have been unsuccessful. Such compounds are highly desirable since they would contain a large quantity of metal in the molecule and would be, therefore, useful in a variety of applications. As examples, such compounds would find application in gaseous metal plating, as antiknock additives, and in a host of other applications.

It is an object of this invention to provide a novel class of transition metal compounds in which a monoolefin is bonded to the transition metal. A further object is to provide fluorinated monoolefin-group VBVllI transition metal-carbonyl compounds. A still further object is to provide a process for the preparation of these compounds. Additional objects will become apparent from a reading of the specification and claims which follow.

The objects of this invention are accomplished by providing compounds represented by the following formulae:

In the above Formula I, Q is a fluorinated monoolefin in which the fluorine atoms are substituted about the double bond, and M is a group VBVII-I transition metal capable of forming simple metal carbonyls and requiring an even number of electrons to attain the electron configuration of the next higher inert gas. z is an integer ranging from one to three, x is an integer ranging from two to five, and the sum of z plus x is equal to an integer which is equal to one-half the number of electrons required by the transition metal, M, to attain the configuration of the next higher inert gas. As an example, chromium requires 12. electrons to attain the inert gas configuration of krypton. Thus, the sum of 2 plus x in the case of chromium is equal to six. The sum of 2 plus x for iron, which requires only 10 electrons to reach rare gas configuration, is five. Likewise, the sum of z plus x for nickel is equal to four since nickel requires eight electrons to reach rare gas configuration.

In Formula II above, M is a transition metal of groups VB-VIII which requires an odd number of electrons in order to attain the configuration of the next higher rare gas. Examples of such metals are vanadium which requires 13 electrons, manganese which requires 11 electrons and cobalt which requires nine electrons in order to attain the electronic configuration of krypton. p is an integer ranging from four to six, and Q is a fluorinated monoolefin, as described above, which is bonded to both of the metal atoms M and forms a bridge between them.

3,113,145 i atented Dec. 3, 1963 In both types of my novel compounds, the transition metal atom or atoms, M or M, attains the configuration of the next higher inert gas by virtue of the electrons donated by the Q and CO groups. This results in my compounds having relatively high stability as compared with other transition metal compounds.

The fluorinated monoolefin Q, as set forth in the above formulae, has the following structure:

In this formula, R is a univalent hydrocarbon group such as an alkyl, aryl, cycloalkyl and the like, hydrogen, or a halogen such as fluorine, bromine, chlorine or iodine. Preferably, R, if a hydrocarbon group, contains from one to about eight carbon atoms. R, in the most preferred case, is fluorine which results in the monoolefin being perfluoroethylene. Perfiuoroethylene is most preferred because it bonds readily to the transition metal and thereby forms compounds having a high degree of stability.

My compounds are prepared by reacting a fluorinated monoolefin, as defined above, with a metal carbonyl of a group VB-VIII metal. A preferred temperature range for carrying out this reaction is between about 25 to about 250 C. Preferred pressure conditions are from about one atmosphere to about atmospheres.

The process is preferably conducted under a blanketing atmosphere of an inert gas such as nitrogen, helium, argon and the like.

In many cases, the fluorinated monoolefin reactant may be used in sufficient excess to act as the reaction solvent. In other cases, however, a neutral solvent may be employed. The nature of the solvent is not critical so long as the reactants have a reasonable degree of solubility in it and do not react with it.

Typical of reaction solvents which may be employed in my process are high boiling saturated hydrocarbons such as n-octane, n-decane, and other paraffinic hydrocarbons having up to about 20 carbon atoms such as eicosane, pentadecane, and the like. Typical ether solvents are ethyl octyl ether, ethyl hexyl ether, diethylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, trioxane, tetrahydrofuran, ethylene glycol dibutyl ether and the like. Ester solvents which may be employed include peutyl butanoate, ethyl decanoate, ethyl hexanoate, and the like. Silicone oils such as the dimethyl polysiloxanes, bis(chlorophenyl) polysiloxanes, hexapropyldisilane, and diethyldipropyldiphenyldisilane may also be employed. Other ester solvents are those derived from succinic, maleic, glutaric, adipic, pimelic, suberic, azelaic, sebacic and pinic acids. Specific examples of such esters are di-(Z-ethylhexyl) adipate, di-(Z-ethyl- 'hexyl) azelate, -di-(2-ethylhexyl) sebacate, (ii-(methylcyclohexyl) adipate and the like. Of these enumerated solvents, those which are preferred for use in the process are the high boiling others and saturated aliphatic hydrocarbons. All of the above solvents will not be suitable for all of the specific embodiments of the invention since certain of the methyl carbonyl reactants are relatively insoluble in some of the above solvents. Thus, care should be used in selecting the specific solvent for the specific reaction.

The particular solvent employed in any embodiment of the process should be selected from those solvents having the requisite boiling and/or freezing point. Frequently the boiling point of the solvent is used to control the reaction temperature when the process is carried out at atmospheric pressure. In such cases, the reaction mixture is heated at reflux, and the reflux temperature is determined by the boiling point of the solvent. The ease of separating the product from the solvent depends on the degree of difference between the boiling and/or freezing points of the product and the solvent. If the product is a liquid having a boiling point close to that of the solvent, it is obvious that separation will be diificult. In order to avoid this, it is preferable to select a solvent whose normal boiling point varies by at least C. from the normal boiling point of a liquid product. If, on the other hand, the product is a solid, it is desirable that the freezing point of the solvent be at least 25 less than the temperature at which separation of the product is eifected through crystallization. Obviously, if the solvent freezes before the solid product precipitates, it will be impossible to make a separation through crystallization.

The above criteria, as to physical properties of the solvent, are not unique to my process. In any chemical process, it is necessary to pick a solvent whose physical properties make it readily separable from the product being formed. It is deemed, therefore, within the skill of the art to select the most suitable solvent for use in any particular embodiment of the process of my invention.

The process is preferably conducted with agitation of the reaction mixture. Although agitation is not critical to the success or failure of the process, its use is preferred since it accomplishes a smooth and even reaction rate.

The time required for the process varies depending on the other reaction variables. In general, a time period ranging from about minutes to about eight days is sufficient.

In some cases, the process is advantageously carried out in the presence of an ultraviolet light source. This can tend to decrease the reaction time and give a higher yield of product. In some cases the metal carbonyl reactant employed in the process is more expensive than the fiuorinated monoolefin reactant. In order to insure maximum conversion of the metal carbonyl, it is, therefore, preferred in those cases to use excess quantities of the olefin. Generally, from about one to about 10 moles of the monoolefin compound are employed for each mole of the metal carbonyl reactant since, within this range, a good conversion of the metal carbonyl is obtained. In other cases, the fiuorinated monoolefin is more expensive than the particular metal carbonyl employed. In these instances, excess metal carbonyl reactant (from one to about 10 moles of metal carbonyl per mole of the olefin reactant) is employed to insure complete conversion of the fiuorinated monoolefin compound.

To further illustrate my novel compounds and the process used in preparing them, there are presented the following examples in which all parts and percentages are by weight unless otherwise indicated.

Example I Two parts of triiron dodecacarbonyl and excess perfluoroethylene were placed in a sealed reaction vessel. After heating the reaction mixture for 12 hours at 120 C., the reaction vessel was discharged, and the product was separated from the reaction mass by means of vacuum sublimation. There was obtained in percent yield the compound, bis(tetrafiuoroethylene) iron tricarbonyl, having a melting point of 77 C. On analysis, there was found: C, 24.7; F, 44.4; Fe, 16.9 percent. (C F Fe(CO) requires: C, 24.8; F, 44.8; Fe, 16.5 percent.

Example 11 Two parts of dicobalt octacarbonyl were placed in a sealed reaction vessel together with excess tetrafiuoroethylene. After heating for seven days at a temperature of 25 C., the reaction vessel was dis-charged. The reaction mass was then subjected to vacuum sublimation to give a good yield of a yellow crystalline product having a melting point of 70 C. The product, bis(cobalt Ind tetracarbonyl) periluoroethylene was analyzed, and there was found: Co, 26.2; C, 27.0; F, 16.4 percent.

(CO) CoCF -CF Co(CO) requires: Co, 26.7; C, 27.2; F, 17.2 percent.

Example 111 One mole of dirnangenese dccacarbonyl and five moles of 1,1,2-trifiuoropropene-1 are dissolved in tetrahydrofuran and placed in a sealed reaction vessel. After heating the reaction mixture for 15 hours at C., the product is discharged and solvent is stripped off by heating in vacuo. The residue is dissolved in low-boiling petroleum ether and chromatographed on alumina to give a good yield of bis(rnanganese pentacarbonyl) 1,1,2-trifluoropropene-l.

Example IV One mole of vanadium carbonyl and three moles of perfiuoropropene are dissolved in tetrahydrofuran and charged to a closed reaction vessel. After heating at 40 C. for 12 hours, the reaction mass is discharged and excess perfluoropropene is removed by heating in vacuo. The residue is dissolved in low-boiling petroleum ether and chromatographed on alumina to give a good yield of bis(vanadium hexacarbonyl) perfiuoropropene.

Example V One mole of chromium hexacarbonyl and four moles of 1,1,2-trifiuorohexene-l are charged to a closed reaction vessel and heated for 10 hours at 149 C. with agitation. The reaction product is then discharged, excess 1,1,2- trifiuorohexene-l is stripped off, and a good yield of tris(1,1,2-trifluorohexene-1) chromium tricarbonyl is obtained by dissolving the residue in petroleum ether and chromatographing on alumina.

Example VII One-half mole of molybdenum hexacarbonyl and two moles of 1,2-difiuorobutene-1 are charged to a closed reaction vessel under a nitrogen atmosphere. After heating for 30 hours at C. with agitation, the reaction product is discharged, and a good yield of tris(1,2-difiuorobutene-l) molybdenum tricarbonyl is obtained by means of chromatographic separation.

Example VIII Ten moles of 1,1,2-trifluoroheptene-1 and one mole of tungsten hex-acarbonyl are charged to a closed reaction vessel which is then pressurized with nitrogen. After heating the reaction mixture for 25 hours at C., the reaction vessel is discharged, and excess 1,1,2-trifluoroheptene-l is removed from reaction mass by heating in vacuo. The residue is dissolved in petroleum ether and chromatographed on alumina to give a good yield of iris (1,1,2-trifluoroheptene-1) tungsten tricarbonyl.

Example IX Ten moles of tn'iron dodecacarbonyl and one mole of 1,1,Z-trifluorochloroethylene are charged to a closed reaction vessel and heated for 15 hours at 115 C. under a nitrogen atmosphere with constant agitation. The re action product is then discharged and subjected to fractional sublimation to give a good yield of bis(1,1,2-trifluorochloroethylencliron tricarbonyl.

As shown by the preceding examples, fi-uorinated monoolefins react readily with group VB-Vlll metal carbonyls to yield products of two types. 'In the case of the group VB-Vlll transition metals which require an odd number of electrons to attain the electronic configuration of the next higher rare gas, the fluorinated monoolefin bridges two such metal atoms each of which is further bonded to a plurality of carbonyl groups. The reaction mechanism involved in the formation of such compounds can be termed a bridging reaction since this describes the function of the fiuorinated monoolefin in bonding to and bridging the two transition metal atoms.

In the case of the transition metals of groups VB-V'I'II which require an even number of electrons to attain the electronic configuration of the next higher inert gas, the reaction takes a different course. In this case, the fluorinated monoolefin displaces carbonyl groups from the metal carbonyl reactant to form compounds containing a single transition metal atom having bonded to it both carbonyl groups and fluorinated monoolefin groups. This reaction can be termed a displacement reaction since it describes the action of the fluorinated monoolefin in displacing carbonyl groups.

Other forms of my process involve the reaction of fluoninated monoolefins with carbonyl-containing compounds of the groups VB-VIH metal carbonyl compounds which are not simple metal carbonyls. Examples of such compounds are sodio manganese pentacarbonyl, manganese pentac-arbonyl hydride, benzene chromium trioarbonyl, cyclopentadienyl manganese tricarbonyl, toluene molybdenum tricarbonyl and the like. In the case of these compounds, the fluorinated monoolefin reacts in an analogous manner to that described above by either displacing groups from the transition metal atom or forming a bridge between transition metal atoms.

Among the important uses of my compounds is their use as fuel and oil additives. For example, they are useful antiknocks when added to gasoline. They may be used as primary antiknocks in which they are the major antiknock component in the fuel or as supplemental antiknocks. When used as supplemental antiknocks, they are present as the minor antiknock component in the fuel in addition to a primary antiknock such as a tetra-alkyllead compound. Typical alkyllead compounds are tctraethyl-lead, tetrabutyllead, tetramethyllead and various mixed lead alkyls such as dimethyldiethyllead, diethyldibutyllead and the like. When used as either a supplemental or primary antiknock, my compounds may be present in the gasoline in combination with typical scavengers such as ethylene dichloride, ethylene dibromide, tricresylphosphate, trimethylphosphate and the like.

The compounds of my invention have further utility as adidtives to residual and distillate fuels generally, e.g., jet fuels, home heater fuels and diesel fuels, to reduce smoke rand/or soot formation. Also, they may be employed as additives to lubricating oils in which case they act to improve the lubricity of the base oil.

My compounds are further usefiil in many metal plating applications. In order to effect metal plating using the compounds, they are decomposed in an evacuated space containing the object to be plated. On decomposition, they lay down a film of metal on the object. The gaseous plating may be carried out in the presence of an inert gas so as to prevent oxidation of the plating metal or the object to be plated during the plating operations.

The gaseous plating technique described above finds wide application in forming coatings which are not only decorative but also protect the underlying substrate material.

Deposition of metal on a glass cloth illustrates the applied process. A glass cloth band weighing one gram is dried for one hour in an oven at C. 'It is then placed in a tube which is devoid of air and three is added to the tube 0.5 gram of bis(cobalt tetracarbonyl) perfiuoroethylene. The tube is heated at 400 C. for one hour after which time it is cooled and opened. The cloth has a uniform metallic grey appearance and exhibits a gain in weight of about 0.02 gram.

A further utility for my compounds is as drying agents in which case the compounds are incorporated in paints, varnish, printing inks, synthetic resins of the drying oil type, oil enamels and the like. A still further utility of my compounds is their use as chemical intermediates in the preparation of metal-containing polymeric materials or in the preparation of new organic materials.

Having fully defined the noved compounds of my invention, their novel mode of preparation and their many utilities, I desire to be limited only within the lawful scope of the appended claims.

I claim:

1. Organomctallic compounds having the formula (CO) l /lQM(C-O) in which Q is a fiuorinated monoolefin having the formula wherein R is selected from the class consisting of hydrogen, halogen and univalent hydrocarbon groups having one to eight carbon atoms, said hydrocarbon groups being selected from the class consisting of alkyl and cycloalkyl groups, and M is an odd atomic number transition metal selected from the class consisting of groups VB, VI l'B and cobalt subgroup metals, which are capable of forming simple metal carbonyls, and p is an integer having a value of 4 to 6.

2. Process for forming the compounds of claim 1, said process comprising reacting a fiuorina-ted monoolefin having the formula R-C=OR in which R is selected from the class consisting of hyduogen and halogen and univalent radicals having one to eight carbon atoms selected from the class consisting of alkyl and cycloalkyl radicals, with a simple metal carbonyl of a transition metal selected from the class consisting of groups VB, VTIB and cobalt subgroup metals.

3. The process of claim 2 wherein the fluorinated monoolefin is perfiuoroethylene.

4. The process of claim 3 wherein the simple metal carbonyl is dicobalt octacarbonyl.

5. As a new composition of matter, the product obtained by reacting (a) a fluorinated monoolefin having the formula I wherein R is selected from the class consisting of hydrogen, halogen and univalent hydrocarbon groups having one to 8 carbon atoms, said hydrocarbon groups being selected from the class consisting of alkyl and cycloalkyl groups, with (b) a simple metal carbonyl of an even atomic number transition metal selected from the class consisting of the group VTB and iron subgroup metals and nickel.

6. The product of claim 5 wherein the simple metal carbonyl reactant is triiron dodecacarbonyl.

7. Bis(cobalt tetracarbonyl) perfluoroethylene.

References (Iited in the file of this patent Hall-am et 'al.: Iour. of the Chem. Soc, pages 642-645,

February 1958.

Webb et al.: J. Am. Chem. Soc, pages 2654-2655, volume 73 (1951).

Claims (1)

1. ORGANOMETALLIC COMPOUNDS HAVING THE FORMULA (CO)PM''QM''(CO)P IN WHICH Q IS A FLUORINATED MONOOLEFIN HAVING THE FORMULA