3,009,766 United States Patent 0 " ice Patented Nov. 21, 1961

1 2 inates problems under a wide variety of storage condi 3,009,766 tions. This thermal stability is also tremendously im DIHALODIMANGANESE OCTACARBONYIS AND portant in that the dihalodimanganese octacarbony-ls de PROCESS FOR PRODUCING THE SAME compose at the correct point in the combustion cycle of Vernon R. Sandel, L’Anse, Mich., assignor to Ethyl Cor poration, New York, N.Y., a corporation of Delaware the spark ignition engines operated on fuels containing No Drawing. Filed Aug. 11, 1958, Ser. No. 754,152 these compounds. This means that the compounds can 10 Claims. (CI. 23-14) exert their profound antiknock effects under conditions where less thermally stable additives would have already This invention relates to and has as its chief object been decomposed. the provision of new halomanganese carbonyls and 10 The bene?cial thermal stability properties of the com processes for their preparation. pounds of this invention are also of great value when the Provided by this invention are dihalodimanganese octa compounds are used in conjunction with organolead anti carbonyls having the empirical formula knock agents. Because of their stability, the dihalodiman ganese octacarbonyls decompose relatively late in the X2Mn2 (Co) a 15 engine cycle and thereby liberate the halogen in a form where the X’s are halogen atoms. Typical of these com that reacts with the decomposition products of the organo pounds are bromochlorodimanganese octacarbonyl, di lead antiknock agent. Formed are relatively volatile ?uorodimanganese octacarbonyl, bromoiododimanganese lead halides which are removed from the engine via the octacarbonyl, etc. It is preferable that the two halogen exhaust gas stream. Hence, the compounds of this in atoms be the same and that the halogen have an atomic 20 vention are not only powerful antiknocks, but possess weight between 35 and 127. In other words, the pre— good scavenging characteristics. ferred compounds of this invention are dichlorodiman The thermal stability of the dihalodimanganese octa ganese octacarbonyl, dibromodimanganese octacarbonyl carbonyls is also exceedingly important insofar as their and diiododimanganese octacarbonyl. use as chemical intermediates is concerned. These com These novel compounds exist as dimers, and thus can 25 pounds can thus be heated to cause various chemical be represented by the formula reactions to take place without inopportune thermal de composition occurring. Therefore, the fact that dihalo dimanganese octacarbonyls have much greater thermal where X is halogen. They are characterized by being stability than other manganese carbonyl halides makes very stable, crystalline substances. They have no sharp 30 these compounds of extraordinary value in the chemical melting points and are not readily sublima-ble. They are and allied arts. The above distinguishing features of the soluble in various organic solvents and, therefore, have compounds of this invention set them apart from the solubility in hydrocarbons, including gasoline, jet fuel, compounds known heretofore. diesel fuel, burner fuel, lubricating oils, and the like. There exist a number of ways of preparing the com They are also characterized by being essentially insoluble 35 pounds of this invention. One elegant method-a pre in water. ferred embodiment of this invention—-involves the pyrol The di'halodimanganese octacarbonyls are powerful ysis of halomanganese pent-acarbonyls. In this thermal antiknock agents when dissolved in gasoline even at very reaction, the compounds of this invention are formed in low concentrations (e.g., 0.005-0.2 gram of manganese good yield and in high purity. Carbon monoxide is a per gallon). This antiknock potency is especially pro by-product. The heating can be carried out in the pres nounced when these compounds are used in conjunction ence or absence of an inert solvent. However, use of with organolead antiknock agents, such as tetraethyllead. a solvent is preferable because of better temperature con Thus, very small concentrations of dihalodimanganese trol. The pyrolysis temperature is generally that which octacarbonyls in gasolines containing from about 0.5 to is su?icient to cause the liberation of carbon monoxide about 10 grams of lead per gallon cause very substantial 45 from the reaction mixture. Thus, temperatures in the improvements in the octane quality of the fuel. range of 30 to 150° C. can be used, depending upon The water insolu-bility of the ‘dihalodimanganese octa whether or not a solvent is used; the type of solvent, if carbonyls is a vitally important factor in their utility as used; and the particular halomanganese pentacarbonyl antiknocks. Because they are so insoluble in water, their used as the starting material. Generally speaking, higher gasoline solutions are not deprived of the valuable manga 50 temperatures should be used when the halomanganese nese content by means of water extraction. Thus, gaso pentacarbonyl is the chloro or lbromo compound. Some lines containing these compounds can be processed, stored, what lower temperatures can 'be used when heating iodo and shipped in the customary manner. Contact with manganese pentacarbonyl. In most cases, temperatures water which is encountered in such customary opera ranging from about 75 to about 100° C. are preferred tions has no adverse leaching el‘I’ect upon these fuels. 55 as the pyrolysis reaction occurs very readily and smoothly Another tremendously important factor making the at these temperatures. Solvents which can be elfectively present compounds ideally suited as fuel antiknocks is used in this process are those which are inert liquids their very great thermal stability. This means that gaso having boiling points above the temperature used to line solutions of dihalodimanganese octacarbonyls can effect pyrolysis. Thus, these solvents include such halo be stored for long periods of time at elevated tempera .60 genated hydrocarbons as carbon tetrachlodide; chloro tures (e.g., desert storage) without fear of catastrophic form; methylene chloride; 1,1,1-trichloroethane; dichloro thermal deterioration. This is important because thermal benzene; bromobenzeue; bromoform; etc. Ethers, such deterioration would not only result in the formation of as tetrahydrofuran, etc., and hydrocarbons, such as iso sludge and loss of valuable antiknock properties, but octane, decane, xylene, decalin, petroleum ether, mineral would result in the liberation of halogen leading to very 65 oil, etc., can also be used. severe corrosive problems. This would be especially in Another way of making the compounds of this inven tolerable if such thermal decomposition occurred in gaso t-ion involves pyrolyzing aromatic manganese tricarbonyl lines stored over water. In such systems halogen decom halides, such as benzene manganese tricarbonyl bromide, position products are readily hydrolyzed. The resultant toluene manganese tricarbonyl chloride, mesitylene man halogen acids are known to be severely corrosive of stor 70 ganese tricarbonyl iodide, and the like. The reaction con age tanks, pipelines, and so on. Hence, the very great ditions for this reaction are generally similar to those thermal stability of the compounds of this invention elim described above, except that somewhat higher tempera 3,009,766 3 4 tures are desirable. Thus, the use of a solvent of the However, generally speaking, concentrations of dihalo type described above is optional, though preferable. The dimanganese octacarbonyls equivalent to from about temperatures which are su?icient to cause the liberation 0.005 to about 0.2 gram of manganese per gallon are of carbon monoxide range from about 80 to about 180D C. preferred. At these concentrations, signi?cant improve The following speci?c examples in which all parts and ments in octane quality are achieved because of the percents are by weight illustrate various aspects of this potency of the compounds of this invention in this invention. regard. Example I It is preferable to use the dihalodimanganese octa A mixture of 5.5 parts of bromomanganese pentacar carbonyls as antiknocks in conjunction with organolead bonyl (0.02 mole) in 96 parts of carbon tetrachloride 10 antiknock agents, such as tetramethyllead, tetraethyllead, was re?uxed for approximately 45 minutes. Carbon tetrabutyllead, methyl triethyllead, tetraoctyllead, di monoxide was evolved during this time and the mixture methyldiethrylleadl, tetratolyllead, and the like. Such became progressively darker. The reaction mixture was combinations of antiknock agents cause especially great then cooled to room temperature and a dark, coppery improvements in octane quality, particularly when the colored crystalline material precipitated from the solvent amount of the lead antiknock exceeds that of the dihalo in a 65 percent yield. Chemical analysis showed this dimanganese octacarbonyl. Thus, excellent results are product to ‘be dibromodimanganese octacarbonyl. Cal achieved in gasolines containing from about 0.5 to about culated for CsOsMnzBrz: carbon, 19.43 percent; manga 10 grams of lead per gallon as an organolead antiknock nese, 22.3 percent; bromine, 32.39 percent. Found: agent and from about 0.005 to about 0.2 gram of manga carbon, 19.7 percent; manganese, 22.7 percent; bromine, 20 nese per gallon as a dihalodimanganese octacarbonyl. 34.3 percent. For most purposes, lead concentrations ranging from Example II about 0.5 to ‘about 6.3 grams per gallon are preferable. In these leaded fuel compositions the dihalodimanga Using essentially the procedure of Example I, dichloro< nese octacarbonyls also provide scavenging action. These dimanganese octacarbonyl was prepared from chloro 25 thermally stable compounds decompose late in the engine manganese pentacarbonyl. During the re?uxing of the cycle and not only exert a profound antiknock effect chloromanganese pentacarbonyl in carbon tetrachloride, thereby, but liberate their contained halogen. This halo~ gas evolution and darkening of the solution occurred. gen is in such a form (probably halogen acids) that it On cooling to room temperature, orange crystals pre readily reacts with decomposition products of the organo cipitated. These were ?ltered off and dried. Infrared lead antiknock agent to form lead salts containing halo spectrum analysis positively identi?ed the product as gen. These, in turn, are swept out of the engine and, dichlorodimanganese octacarbonyl. therefore, pose no operational di?iculties. Example III Demonstrations of the antiknock and scavenging prop erties of the dihalodimanganese octacarbonyls involve The procedure of Example I is repeated using 7 parts 35 operating gasoline engines on the foregoing fuel composi of iodomanganese pentacarbonyl instead of the bromo~ tions. Quantitative measurements of the antiknock manganese pentacar-bonyl. A good yield of diiododi potency of the compounds of this invention are obtained manganese octacarbonyl is formed. by using standard engine rating methods, such as the The above examples illustrate the preferred process of standard ASTM Motor Method (D-357) or the standard this invention—viz, pyrolysis of halom'anganese penta 40 ASTM Research Method (D-908), both of which are carbonyl. described in ASTM Manual of Engine Test Methods, Example IV 195 6 Edition. Other standard engine test procedures are also described in the literature. One part of toluene manganese t-ricarbonyl iodide was The compounds of this invention are also exceedingly heated to 125° C. in a nitrogen atmosphere. At 97-98“ useful as chemical intermediates. For example, they can C. the material melted to a deep, red liquid and shortly 45 be used to prepare cyclopentadienyl manganese tricar afterward gave off a small amount of gas (carbon mon bonyl compounds among which are the most powerful oxide). At 110” C. the liquid began to re?ux. After antiknock compounds known to mankind. The excellent holding the sample at 125° C. for ?ve minutes, much of antiknock and supplementary properties of cyclopenta it again solidi?ed. Upon cooling, the product was leached 50 dienyl manganese tricarbonyls is set forth in US. Patents with hot isooctane, yielding a red solution from which 2,818,416 and 2,818,417. red-brown crystals precipitated. This was subjected to The following is a typical method of preparing a cycle chemical analysis and found to be diiododimanganese pentadienyl manganese tricarbonyl from a dihalodiman octacarbonyl. It did not melt, but sublimed with decom ganese ootacarbonyl: One-tenth of a gram mole of di position at 110° C. under full pump vacuum (0.01 mm. 55 bromodimanganesc octacanbonyl and two-tenths of a of mercury). Analysis showed the product to contain gram mole of sodium cyclopentadienide are re?uxed in 16.4 percent of carbon; 18.3 percent of manganese and 300 milliliters of tetrahydrofuran for 30 minutes. The 46.3 percent of iodine. Theoretical values: carbon, 16.3 reaction mixture is cooled, hydrolyzed and the solvent percent; manganese, 18.7 percent; iodine, 43.2 percent. evaporated by vacuum ‘distillation. Cyclopentadienyl Example V manganese tricarbonyl is sublimed from the residue at 50° C., using full pump vacuum. The procedure of Example IV is repeated with the The d-ihalodim-anganese octacarbonyl compounds may exception that mesitylene manganese tricarbonyl chloride be incorporated in paints, varnish, printing inks, synthetic is used as the starting material. Dichlorodiman-ganese resins of the drying oil type, oil enamels, and the like octacarbonyl is the resultant product. 65 to impart excellent drying characteristics to such com Use of the dihalodi-manganese octacarbonyls as anti positions. Generally speaking, from 0.01 to 0.05 percent knock agents involves dissolving them in appropriate con of manganese ‘as a compound of this invention is bene centration with hydrocarbons of the gasoline boiling ?cially employed as a dryer in such a composition. range. When used as primary antiknocks, the concen For example, to ‘a typical varnish composition con tration of manganese as a dihalodimanganese octacara 70 taining 100 parts ester gum, 173 parts of tung oil, 23 bonyl may range from about 0.002 to about 0.5 gram of parts of linseed oil and 275 parts of white petroleum manganese per gallon. Higher concentrations ‘may be naphtha is added 3.0 pants of dichlorodimanganese octa used to obtain still greater increases in octane quality. carbonyl. The resulting varnish composition is found to In such cases the use of an auxiliary organic solvent pro have excellent drying characteristics. Equally re motes more rapid and uniform blending procedures. 75 sults are obtained when other drying oil compositions 3,009,766 6 and other dihalodimanganese octacarbonyl compounds of saturating this solution with postassium iodide, ivory this invention are used. colored crystals of mesitylene manganese tricarbonyl io The compounds of this invention are also very useful dide are precipitated. This general procedure is appli additives to such petroleum hydrocarbon products as jet cable to the preparation of aromatic manganese tricar fuels, diesel fuels, iburner fuels, and lubricating oils. A bonyl halides of the formula multitude of bene?cial functions are served when the compounds of this invention are so used. For example, the presence of 'dihalodim-anganese octacarbonyls in jet where A is an aromatic compound coordinated with the fuels, diesel fuels, and burner fuels results in the elimina manganese atom and X is a halogen. What is claimed is: tion or substantial reduction of sooty deposits and smoke. 10 Concentrations of manganese ranging from 0.001 to about 1. Dihalodimanganese octacarbonyls selected from the 0.5 gram per gallon are useful in this regard. When group consisting of dichlorodimanganese octacarbonyl used at similar concentrations in crankcase lubricating and dibromodimanganese octacarbonyl. oils, supplemental antiknock effects are achieved. 2. Dichlorodimanganese octacarbonyl. 3. Dibromodimanganese octacarbonyl. Other important uses of the dihalodimanganese octa 15 carbonyls of this invention include their use as chemical 4. Process comprising pyrolyzing a compound selected intermediates in the preparation of metal and metalloid from the group consisting of chloromanganese pentacar containing polymeric materials. In addition, these com bonyl, and bromoma-nganese pentacarbonyl at a tempera pounds can be used in the manufacture of medicinals and ture at which carbon monoxide is evolved. 5. Process for preparing dichlorodimanganese octacar other therapeutic materials, as well as agricultural chem 20 icals, such as fungicides, defoliants, growth regulants, bonyl which process comprises pyrolyzing chlorornan and so on. ganese pentacarbonyl at a temperature at which carbon The starting materials used in the preparation of the monoxide is evolved. dihalodimanganese octacarbonyls can be prepared in high 6. Process for preparing dibromodimanganese octacar bonyl which process comprises pyrolyzing bromoman yield. An elegant way of making halomanganese penta 25 carbonyls involves reacting free halogen with diman ganese pentacarbonyl at a temperature at which carbon ganese decacarbonyl in an inert, liquid-organic solvent, monoxide is evolved. such as carbon disul?de. Temperatures ranging from 7. The process of claim 6 wherein the pyrolysis is about 0 to about 100° C. can be used. An excellent way carried out in the presence of an inert solvent having a of preparing aromatic manganese tricarbonyl halides, boiling point which is higher than the pyrolysis tempera such as mesitylene manganese tricarbonyl iodide, toluene ture. manganese tricarbonyl iodide, benzene manganese tri 8. The process of claim 7 wherein the pyrolysis tem— carbonyl iodide, toluene manganese tricarbonyl chloride, perature ranges from about 75 to about 100° C. ethylbenzene manganese tricarbonyl ?uoride, biphenyl 9. The process of claim 5 wherein the pyrolysis is car ried out in the presence of an inert solvent having a manganese tricarbonyl bromide, etc., involves reacting an 35 aromatic hydrocarbon compound with a manganese pen boiling point which is higher than the pyrolysis tempera tacarbonyl compound in the presence of a Friedel-Crafts ture. catalyst. Temperatures of 20 to 300° C. preferably 50 to 10. The process of claim 9 wherein the pyrolysis tem 200° C. are used. To illustrate, 2 parts of bromomanga perature ranges from about 75 to about 100° C. nese pentacarbonyl, 2 parts of aluminum chloride and 30 40 parts of mesitylene are re?uxed (at about 165° C.) under References Cited in the ?le of this patent nitrogen. The mixture is then hydrolyzed with 20 parts E. O. Brimm ert al.: Journal of the American Chemical of water, resulting in a pale yellow water layer. Upon Society, vol. 76, 1954, pages ‘3831-3835.