US3097224A - Acetylene nickel compounds - Google Patents

Description

United States Patent 3,097,224 ACETYLENE NICKEL CONPOUNDS Michael Dnbeck, Royal Oak, Mich, assignor to Ethyl Corporation, New York, NY, a corporation of Virginia No Drawing. Filed Nov. 12, 1959, Ser. No. 852,216 16 Claims. (Cl. 260-439) This invention relates to novel organometallic compounds and their mode of preparation. More specifically, this invention relates to bis(cyclornatic nickel) acetylene compounds wherein each nickel atom is bonded to a cyclomatic hydrocarbon group, to another nickel atom, and to an acetylene compound which is bonded to both of the two nickel atoms.

It is an object of this invention to provide a novel class of bis(cyclomatic nickel) acetylene compounds. A further object is to provide a process for the preparation of these compounds. Another object is to provide fuel antiknock mixtures wherein a bis(cyclomatic nickel) acetylene compound is present as a primary antiknock or as a supplemental antiknock in addition to another antiknock material. Additional objects of this invention will become apparent from a reading of the specification and claims which follow.

The objects of this invention are accomplished by pro viding compounds represented by the formula:

QCE CQ CyNiNiCy' Although not bound by any theory, these compounds are believed to have the structural formula as follows:

In this formula, Q and Q represent either hydrogen or univalent hydrocarbon radicals containing from one to about carbon atoms. Cy and Cy represent cyclomatic hydrocarbon groups which donate five electrons to the nickel atoms for bonding. By virtue of the electrons d0- nated to each of the nickel atoms from the cyclomatic hydrocarbon groups, the acetylene molecule and the other nickel atom, each of the nickel atoms present in the compounds of my invention, achieves the inert gas electron configuration of krypton.

The cyclomatic hydrocarbon groups, designated by the symbols Cy and Cy in the above formula, may be the same or different and are cyclopentadienyl-type hydrocarbon radicals. By this, it is meant that the radical contains the cyclopentadienyl moiety. In general, such cyclomatic hydrocarbon groups can be represented by the formulae:

wherein the Rs are selected from the group consisting of hydrogen and univalent hydrocarbon radicals.

A preferred class of cyclomatic radicals suitable in the practiceXof my invention are those which contain from five to about 13 carbon atoms. These are exemplified by cyclopentadienyl, indenyl, methylcyclopentadienyl, propylcyclopentadienyl, diethylcyclopentadienyl, phenylcyclo pentadienyl, tert-butyl cyclopentadienyl, p-ethylphenyl cyclopentadienyl, 4-tert-butyl indenyl and the like. The compounds which yield these radicals are preferred as they are the more readily available cyclomatic compounds, and the compounds of my invention containing these radicals have the more desirable physical characteristics which render them of superior utility.

3,097,224 Patented July 9, 1963 ice As shown in the above formula, the bridging acetylenetype molecule is believed to be bonded to both of the nickel atoms in forming the compounds of my invention. As visualized, the triple bond in the bridging acetylenic compound is reduced to a single bond thus making four electrons available for bonding to the two nickel atoms. Each of the carbon atoms on either side of the triple bond is thereby bonded to each of the nickel atoms. The actual configuration of the bridging acetylenic molecule is believed to be approximately at right angles to the plane in which the two inter-connected nickel atoms lie. This is shown in the above formula by means of the dotted lines indicating bonding of the carbon atom which is behind the plane of the paper to the two nickel atoms illustrated as lying in the plane of the paper. The other carbon atom which is bonded to the two nickel atoms is depicted as lying in front of the plane of the paper. Thus, the bonds between this carbon atom and the two nickel atoms are drawn as solid lines.

The substituent groups Q and Q, as shown in the above formula, may be the same or different and are hydrogen or univalent hydrocarbon groups containing from one to about 10 carbon atoms. Q and Q are preferably alkyl groups such as methyl, ethyl, propyl, butyl, amyl, octyl or decyl, including normal alkyls or branched chain alkyls. Preferably, Q and Q, if an alkyl group, contains from one to about six carbon atoms since alkyl radicals within this range impart desirable physical properties to the compounds of my invention.

Q and Q may also be an aryl radical, either a fused or single ring, such as phenyl, tolyl, xylyl, naphthyl or the like. In addition, Q and Q may be hydrocarbon groups containing unsatuarted double bonds such -as alkenyl or cycloalkenyl radicals. Typical of such radicals are butenyl, pentenyl, hexenyl, nonenyl, cyclohexenyl, cyclopentenyl and the like. In addition, the Q groups may be alkaryl radicals, ar-alkyl radicals, and cycloal-kyl radicals containing up to about 10 carbon atoms. Typical of such radicals are benzyl, phenylethyl, phenylpropyl, phenylbutyl, cyclohexyl, cyclopentyl, cycloheptyl, cyclodecyl, p-ethylphenyl, rn-butylphenyl, p-methylphenyl and the like.

Although the Q groups, as defined above, are univalent hydrocarbon radicals or hydrogen, these groups may be substituted with polar substituents which preferably should be separated by at least two carbon atoms from the triple acetylenic bond to avoid cumbersome side reactions. Typ ical acetylenic compounds containing such non-reactive non-hydrocarbon substituent groups are perhalo butynes, propargyl alcohol, ethynyl cyclohexanol, beta carboxy esters of the butynes, pentynes, hexynes, and heptynes, 5- methoxy pentyne-l, and the like.

The method by which my compounds are formed involves the following chemical reaction:

QCE C-Q Cy Ni QCECQ CyNi-NiCy This reaction may, in general, be carried out between room temperature and about 150 C. Preferably, however, the reaction is carried out between about 60 to about C. since within this range yields are maximized and undesirable side reactions are minimized.

The pressure at which the reaction is carried out is, in general, not critical. If the acetylenic reactant is a gas, however, the pressure should be sufficiently high to insure that a goodly percentage of the gaseous acetylenic reactant is dissolved in the solution comprising the bis(cyclornatic) nickel reactant and a solvent. Since it is necessary for the gaseous acetylenic reactant to contact the his (cyclomatic) nickel compound in order for reaction to take place, pressure will, in this instance, have a substantial effect on the reaction rate. In general, pressures between about atmospheric and about 10,000 p.s.i.g. may be employed. If the acetylenic reactant is acetylby the use of higher pressure.

The reaction is generally canried out in the presence of a solvent although in certain cases the acetylenic reactant, if used in excess, may serve as the solvent. -In general, any unreactive solvent in which the bis- (cyclomatic) nickel compound is fairly soluble may be employed. Typical of such solvents are high boiling saturated hydrocarbons such as n-octane, n-decane, and other parafiinic hydrocarbons having up to about 20 carbon atoms such as eicosane, pentadecane and the like. Also applicable are aromatic solvents such as benzene, toluene, mesitylene, and the like. Typical ether sol vents 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 pen-tyl 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, glu-taric, adipic,

I pimelic, suberic, azelaic, sebacic and pinic acids. Specific examples of such esters are di-(Z-ethylhexyl) adipate, di-

-(2-ethylhexyl) azelate, di-(Z-ethylhexyl) sebacate, di-

(methylcyclohexyl) adipate and the like. Preferred solvents are the polar ethers such as diethylene glycol dimethyl ether and tetrahydrofuran.

A further criteria for the solvent is that it !be one which is easily separable from the compounds formed in the process. If, for example, the product is a liquid as in the case of his (cyclopentadienyl nickel) hexyne-3, the I solvent should be selected so that it has a normal boiling lization.

The time required for my process will vary in accord- I It generally hours, howmore expensive bis(cyclomatic) nickel reactant, it is preferable in my process to use excess quantities of the acetylenic reactant. In general, I employ from about 0.75 to about 30 moles of acetylenic reactant for each mole of bis(cyclomatic) nickel reactant. Higher or lower quantities of the acetylenic reactant may be used but, in general, I find that quantities within this range insure a relatively high yield of product.

As previously set forth, my invention embraces a variety of bis (cyclomatic nickel) acetylenic compounds. Typical of these compounds are bis(cyclopentadienyl nickel) acetylene, bis(cyclopentadienyl nickel) propyne, !bis(cyclopentadienyl nickel) pentyne-l, bis(cyclopentadienyl nickel) bu-tyne-l, bis(cycl0pentadienyl nickel) phenyla'cetylene, bis(cyclopentadienyl nickel) diphenyl- V culated for acetylene, bis(cyclopentadienyl nickel) butyne-Z, bis- (cyclopentadienyl nickel) hexyne-3, bis(cyclopentadienyl nickel) perfluorobutylene-Z, bis(cyclopentadienyl nickel) decyne-S, bis (methylcyclopentadienyl nickel) octyne-4, bis(indenyl nickel) hexyne-l, bis(cyclopentadienyl nickel) octodecyne-9, bis(cyclopentadienyl nickel) propargyl alcohol, cyclopentadienyl nic'kel methyl cyclopentadienyl nickel hexyne-3, and the like.

Preferably, the process is carried out under a protective atmosphere of an inert gas such as nitrogen, helium, argon and the like. This prevents decomposition of the reactants and/or products and results in the obtaining of higher yields.

To further illustrate my compounds and their mode of preparation, there are presented the following examples in which all parts and percentages are by weight unless otherwise indicated.

anhydrous tetrahydrofuran to form a solution which was sealed in a stainless steel autoclave. Acetylene was added to the autoclave until an equilibrium pressure of 100 p.s.i.g. was attained over the solution. The autoclave was then pressurized to 2,000 p.s.i.g. with pure nitrogen. The reaction mixture was heated for two and one-half hours at C. and allowed to cool overnight. It was then discharged from the autoclave under nitrogen. On filtering, two parts of amorphous decomposition product was separated from the reaction mixture. The solvent was then removed from the remaining reaction mixture under reduced pressure to leave a darkgreen residue. The residue was triturated with a small volume of petroleum ether to remove oil-like contaminants, and the residue was sublimed at 0.05 mm. Hg and room temperature to give 12 parts of nickelocene having a melting point of 172173 C. When sublimation appeared to have ceased, the temperature was raised to 60 C. This caused further sublimation to yield a dank-green solid sublimate. Repeated fractional sublimation followed by recrystallization from petroleum ether yielded 0.5 part of a flaky, light-green lustrous solid having a melting point of 143 C. This solid was analyzed and found to be -bis(cyclopentadienyl nickel) acetylene.

Analysis-Found: C, 52.3; H, 4.49; Ni, 42.6. Cal- (C H Nl) HCECHI C, 52.7; H, 4.39; Ni, 42.9. 7

EXAMPLE II was cooled. The reaction product was filtered to remove some black decomposition product. The black decomposition product was thoroughly washed with low-boiling petroleum ether and the washings were kept separate from the filtrate. The filtrate was cooled to 70 C.

yielding green crystals which were filtered off under nitrogen and washed with cold petroleum ether. The washed crystals were then sublimed at 0.05 mm. Hg and room temperature to give three parts of nickelocene having a melting point of 172l73 C. When the nickelocene had ceased to sublime, the temperature of the sublimator was raised to 60 C. which caused the sublimation of 0.7 part of a dark-green solid. This solid was recrystallized from petroleum ether to yield flaky green crystals having a melting point of 142143 C. with decomposition. An additional 3.1 parts of nickelocene and 0.3 part of the flaky green crystals melting at 143 C. were recovered from the dimethyl carbitol filtrate by dilution with water, extraction with benzene and fractional sublimation. Evaporation of the petroleum ether washings followed by fractional sublimation yielded an additional 1.0 part of nickelocene and 0.2 part of product. On analysis, the flaky green crystals melting at 142-143 C. were found to be bis(cyclopentadienyl nickel) acetylene. The total yield of this compound was 1.2 parts.

EXAMPLE III To 704 parts of benzene were added 20 parts of nickelocene to form a solution which was charged to a stainless steel autoclave. To autoclave was then pressurized with commercial grade acetylene to an equilibrium pressure of about 100 p.s.i.g. The autoclave was then pressurized to 2,000 p.s.i.g. with pure nitrogen and heated at 85 C. for six hours. On discharge, filtration of the reaction mixture yielded about 34 parts of a black nickelcontaining intractable solid. Removal of the solvent from the filtrate under reduced pressure and room temperature gave a brown residue which was triturated with about 320 parts of low-boiling petroleum ether. Removal of the ether solvent followed by repeated fractional sublimation of the residue and recrystallization of the dark-green condensate from petroleum ether yielded about 0.3 part of a flaky green solid having a melting point of 142143 C. with decomposition. This product was found to have an infrared spectrum which was identical to the infrared spectrum of bis(cyclopentadienyl nickel) acetylene as prepared in the previous examples. This proved conclusively that the product obtained was bis(cyclopentadienyl nickel) acetylene.

EXAMPLE IV A solution comprising 20 parts of nickelocene in 710 parts of tetrahydrofuran was charged to a stainless steel autoclave. The autoclave was pressurized to an equilib rium pressure of 85 p.s.i.g. with acetylene, and the reaction mixture was heated at 45 C. for approximately 100 hours. The autoclave Was discharged, and the reaction mixture was filtered. Excess solvent was stripped off under reduced pressure without heating. The green crystalline fractions, which separated as the volume of the solution and the temperature decreased, were filtered under nitrogen and fractionally sublimed at 0.05 mm. Hg. A total of 12.6 parts of unreacted nickelocene and 1.2 parts of bis(cyclopentadienyl nickel) acetylene were isolated. The bis(cyclopentadienyl nickel) acetylene had a melting point of 14l-142 C. and was identical to the bis(cyclopentadienyl nickel) acetylene as prepared in the previous examples.

EXAMPLE V A solution comprising 20 parts of nickelocene dissolved in 622 parts of anhydrous tetrahydrofuran was charged to a stainless steel autoclave along with 100 parts of propyne. The reaction mixture was heated at 85 C. for four and one-half hours after which the reaction vessel was cooled to room temperature. The vessel was then discharged, and the reaction product was filtered. The solvent was removed at room temperature under reduced pressure, and the dark-green residues were triturated with approximately 38.4 parts of petroleum ether and filtered. Sublimation of the triturate residues at room temperature and 0.05 mm. Hg yielded 11 parts of nickelocene. The petroleum ether solubles from the sublimation residues were combined with the dark-green triturate liquors and the whole was chromatographed on alumina and eluted with petroleum ether. This procedure enabled separation of a darkagreen crystalline solid from small amounts of nickelocene in the eluate. Repeated chromatognaphy of the dark-green solid followed by fractional sublimation yielded 2.1 parts of dark-green needle-like crystals having a melting point of 68-69 C. which on Four parts of nickelocene, seven parts of 3-hexyne and 8.9 parts of tetrahydrofuran were charged to a reaction vessel and heated at 100 C. for 15 hours. The reaction vessel was then cooled and discharged. Excess tetrahydrofuran was removed under reduced pressure at room temperature. The dark-green oily residue was dissolved in petroleum ether and chromatographed on alumina. Elution with petroleum ether gave poor resolution of the dark-green product band from traces of unreacted nickelocene. Removal of excess petroleum ether from the center cut of the dark-green product band yielded a light-green residue which was evaporatively distilled at 0.05 mm. Hg and 50 C. Repeated chromatographic purification followed by evaporative distillation failed to cause crystallization at room temperature. The darkgreen liquid possessed infrared absorbencies in the nine to 13 micron regions characteristic of bis(cyclopentadienyl nickel) acetylene. On analysis, the dark-green liquid product (2.4 parts) was found to be his (cyclopentadienyl nickel) hexyne-3.

Analysis.Found: C, 58.6; H, 6.21; Ni, 35.4. Calculated for (C H Ni) C H CECC H C, 58.3; H, 6.10; Ni, 35.6 percent.

EXAMPLE V11 T0 18 parts of nickelocene and 534 parts of tetrahydrofuran in an autoclave was added sufficient acetylene to raise the equilibrium pressure to 180 p.s.i.g. The reaction mixture was heated for 16 hours at C. The autoiclave was then discharged, and the reaction product was filtered. The solvent was removed at room temperature under reduced pressure. The green residue was triturated with about 64 parts of petroleum ether to remove oily contaminants. The residue was then fractionally sublimed at 0.01 mm. Hg. During the sublimation, unreacted nickelocene was sublimed at room temperature whereas the product, bis(cyclopentadienyl nickel) acetylene, required a sublimation temperature of 60 C. Additional nickelocene and product was also isolated from the petroleum ether triturates by means of chromatography on alumina. The total yield of bis(cyclopentadienyl nickel) acetylene, having a melting point of l42-143 C., was 6.3 parts which corresponds to a yield of 71 percent.

EXAMPLE VIII Five parts of nickelocene, 10 parts of l-pentyne and 13.3 parts of tetrahydrofurasn were charged to a sealed reaction vessel and heated at C. for 17 hours. The reaction vessel was discharged under nitrogen, and the solvent was stripped from the reaction product under reduced pressure Sublimation of the crude reaction residue at 0.05 mm. Hg and 60 C. resulted in the isolation of a dark-green liquid which slowly crystallized. Chromatographic purification of the material on alumina, using petroleum ether eluant, removed traces of an oily contaminant. Resublimation of the chromatographed solid gave 1.1 parts of bis(cyclopentadienyl nickel) l-pentyne which was a dark-green solid having a melting point of 505l C. On analysis, there was found: C, 56.4; H, Calculated for (C5H5ND2HCECC3H7: C, 57.0; H, 5.80; Ni, 37.2 percent.

EXAMPLE IX Fifteen parts of nickelocene and 32 parts of Z-butyne were dissolved in 534 parts of tetrahydrofuran. The solution was charged to a stainless steel autoclave and heated at C. for 20 hours. The autoclave was then cooled, and the reaction product was discharged. The re action product was filtered, and solvent was removed under reduced pressure. The green reaction residue was vessel at 120 C. for 10 hours. moved under reduced pressure, and the residue is taken 1 up in low-boiling petroleum ether, chromatographed on EXAMPLE X A solution of 5.0 parts of nickelocene and 10 parts of ethynyl benzene in 26.6 parts of tetrahydrofuran was heated at reflux for 30 minutes under a protective atmosphere of nitrogen. The solvent and unreacted ethynyl benzene were then removed under reduced pressure, and the reaction residue was triturated with low-boiling petroleum ether. The triturates were chromatographed on alumina and eluted with petroleum ether. This procedure yielded one part of unreacted nickelocene. The remaining reaction residues were fractionally sublimed at 0.05

Hg, and an additional 1.5 parts of unreacted nickelocene was obtained. On increasing the temperature of the sublimator to 60 C., there was obtained 0.8 part 'of bis(cyclopentadienyl nickel) phenylacetylene which was a dark-green solid that crystallized rrorn isooctane as dark-green needles having a melting point of 132 C. On analysis, there was found: C, 61.2; H, 4.6; Ni, 33.3. Calculated for (C5H5Nl) HCECC H5I C, 61.8; H, 4.6; Ni, 33.5 percent.

EXAMPLE XI A solution of two parts of nickelocene and two parts of perfluorobutyne-Z in 20 parts of tetrahydrofuran was allowed to stand at room temperature for 70 hours. The viscous reaction mixture was relieved of the volatile solvent at reduced pressures, and the residue was sublimed at 0.02 mm. Hg and 40 C. The sublimate was triturated with low-boiling petroleum ether, and the triturates were chromatographed on alumina and eluted with petroleum ether. This procedure resulted in the recovery of 1.2 parts of nickelocene and 0.05 part of a dark-green crystalline material having a melting point of 93 C. This product was identified as bis(cyclopentadienyl nickel) perfluorobutyne-Z through its elemental analysis and a comparison of its infrared spectrum with the similar infrared spectra of other bis(cyclopentadienyl nickel) alkyne compounds of my invention.

EXAMPLE XII A solution of four parts of nickelocene and three parts of diphenylacetylene in 50 parts of toluene was refluxed for 10 hours. Excess solvent was removed under reduced pressure, and unreacted nickelocene and diphenylacetylene were sublimed out of the reaction mixture under reduced pressures at 50 C. The residue was triturated with petroleum ether, and the triturate was filtered and chilled to Dry Ice temperatures where crystallization occurred. On recrystallization from petroleum ether, there Was obtained one part of bis(cyclopentadienyl nickel) diphenylacetylene having a melting point of 148 C. The compound was. clearly identified as bis(cyclopentadienyl nickel) diphenylacetylene through means of an elemental analysis and the infrared spectrum of the compound which closely resembled those of my other 'bis(cyclopentadienyl nickel) alkyne compounds;

EXAMPLE XIII A solution of 0.2 mole of nickelocene and 0.15 mole of decyne-S is dissolved in isooctane and heated in a sealed Excess solvent is realumina, and eluted with petroleum ether. This results in a good yield of bis(cyclopentadienyl nickel) decyne-S with an infrared spectrum characteristic of the bis(cyclopentadienyl nickel) alkyne compounds.

EXAMPLE XIV This enables the. isolation of a good yield of bis(methyl cyclopentadienyl nickel) oc-tyne-4 with an infrared spectrum characteristic of the bis(cyclopentadienyl nickel) alkyne compounds.

EXAMPLE XV A solution of 0.05 mole of his (indenyl) nickel and 1.5 moles of hexyne-l is heated in a closed vessel at C. for 10 hours. Excess hexyne-l is removed under reduced pressure, and the residue is taken up in petroleum ether and chromatographed on alumina and eluted with petroleum ether. A good yield of bis(indenyl nickel) hexyne-l is obtained.

A further embodiment of the present invention comprises the use of the compounds of my invention as antiknock agents in a liquid hydrocarbon fuel used in spark ignition internal combustion engines. For this use, I provide a liquid hydrocarbon fuel of the gasoline boiling range containing from about 0.05 to about 10 grams per gallon of nickel as a compound of my invention. It is found that these compositions, when employed as fuels for a spark ignition internal combustion engine, greatly reduce the tendency of. the engine to knock.

A preferred composition of my invention comprises a hydrocarbon of the gasoline boiling range containing from about 1.0 to about 6.0 grams of metal per gallon of fuel as a nickel compound as defined previously. This range of metal concentration is preferred since it is found that superior fuels result from its employment.

A further preferred class of compositions of my invention comprises hydrocarbon fuels containing a bis(cyclomatic nickel) acetylenic compound wherein the bridging acetylenic group contains from four to 10 carbon atoms. A still further preferred class of compositions are those in which the bridging acetylenic group contains six carbon atoms. A most preferred composition is that containing bis(cyclomatic nickel) hexyne-3 since these compounds are found to be most excellent antiknock additives.

The base fuels used to prepare the compositions of my invention have a Wide variation of compositions. They generally are petroleum hydrocarbons and are usually blends of two or more components containing a mixture of many individual hydrocarbon compounds.

' These fuels can contain all types of hydrocarbons, in-

- chains; and aromatics containing aliphatic side chains.

The fuel type depends on the base stock from which it is obtained and on the method of refining. For example, it can be a straight run or processed hydrocarbon, includnig thermally cracked, catalytically cracked, refer-med fractions, etc. When used for spark-fired engines, the boiling range of the components in gasoline can vary from zero to about 430 'F., although the boiling range of the fuel blend is often found to be between an initial boiling point of from about 80 F. to F. and a final boiling point of about 430 F. While the above is true for ordinary gasoline, the boiling range is somewhat more restricted in the case .of aviation gasoline. Specifications for the latter often call for a boiling range of from about impurities. One such impurity is sulfur, which can be present either in a combined form as an organic or inorganic compound, or as elemental sulfur. The amounts of such sulfur can vary in various fuels about 0.003 percent to about 0.30 percent by weight. Fuels containing quantities of sulfur, both lesser and greater than the range of amounts referred to above, are also known. These fuels also often contain added chemicals in the nature of antioxidants, rust inhibitors, dyes, and the like.

The bis(cyclomatic nickel) acetylenic compounds of my invention can be added directly to the hydrocarbon fuel, and the mixture then subjected to stirring, mixing or other means of agitation until a homogeneous fluid results. In addition to the bis(cyclornatic nickel) acetylenic compounds, the fuel may have added thereto antioxidants, metal deactiva-to-rs, halohydrocarbon scavengers, phosphorus compounds, anti-rust and anti-icing agents, and supplementary wear inhibitors. The following examples are illustrative of improved fuels of improved fuels of my invention containing a lbis(cyclornatic nickel) acetylenic compound, and also a method for preparing said improved fuels.

EXAMPLE XVI To a synthetic fuel consisting of 20 volume percent toluene, 20 volume percent isobutylene, 20 volume percent isooctane and 40 volume percent n-heptane is added :bis(cyclopentadienyl nickel) hexyne-3 in amount such that the nickel concentration is 0.05 gram per gallon. The mixture is agitated until a homogeneous blend of the bis- (cyclopentadienyl nickel) hexyne-3 compound in the fuel is achieved. This fuel has substantially increased octane value.

EXAMPLE XVII To 1000 gallons of commercial gasoline having a gravity of 59.0" API, an initial boiling point of 98 F. and a final boiling point of 390 P. which contains 45.2 volume percent paraffins, 28.4 volume percent olefins and 25.4 volume percent aromatics is added 10.0 grams per gallon of nickel as bis(cyclopentadienyl nickel) pentyne- 1 to give a fuel of enhanced octane quality.

EXAMPLE XVIII Bis(cyclopentadienyl nickel) diphenylacetylene is added in amount sufficient to give a nickel concentration of 6.0 grams per gallon to a gasoline having an initial boiling point of 93 F., a final boiling point of 378 F. and an API gravity of 562.

EXAMPLE XIX To a liquid hydrocarbon fuel containing 49.9 volume percent paraflins, 15.9 volume percent olefins and 34.2 volume percent aromatics and which has an API gravity of 51.5, an initial boiling point of 11 F. and a final boiling point of 394 F. is added Ibis(cycl-opentadienyl nickel) acetylene to a nickel concentration of 3.0 grams per gallon.

EXAMPLE XX To the fuel of Example XIX is added bis(indenyl nickel) decyne-3 in amount such that the nickel concentration is 2.0 grams per gallon.

A further embodiment of the present invention comprises a liquid hydrocarbon fuel of the gasoline boiling range containing an organolead antiknock agent and in addition a bis(cyclomatic nickel) acetylenic compound as defined previously. In this embodiment of the invention, it is often desirable that the fuel contain also conventional halohydrocanbon scavengers or corrective agents as conventionally used with organolead antiknock agents. When an organolead antiknock agent is employed, it may be present in the fuel in concentrations up to about eight grams of lead per gallon. In the case of aviation fuels, up to 6.34 grams of lead may be employed.

For each gram of lead, there may be present from about 0.008 to about grains of nickel as a bis(cyclornatic 10 nickel) acetylenic compound. A preferred range comprises those compositions containing from about 0.1 to about six grams of nickel as a bis(cyclomatic nickel) acetylenic compound for each gram of lead as an organolead compound.

A preferred embodiment of my invention comprises a liquid hydrocarbon fuel of the gasoline boiling range containing from about 0.5 to about 6.34 grams of lead per gallon as an organolead an-tiknock agent and from about 0.008 to about one gram of nickel per gallon as a bis(cyclomatic nickel) acetylenic compound as defined above. A further preferred aspect of my invention com prises compositions, as defined previously, in which the nickel concentration ranges from about 0.01 to about 0.5

and most preferably from about 0.01 to about 0.3 gram of nickel per gallon. These ranges of metal concentrations are preferred as it has :been found that especially superior fuelsparticularly from a cost-effectiveness standpoint-result from their use.

A most preferred aspect of my invention comprises leaded fuels containing a bis(cyclomatic nickel) acetylenic compound, as defined previously, in which the bridging acetylenic group contains from four to about 10 carbon atoms. Most preferably, the bridging acetylenic group contains six carbon atoms as in the specific compound, bis (cyclopentadienyl nickel) hexyne-3. These compounds are preferred since they have the requisite volatility and solubility in gasoline to make them easily inducted into an internal combustion engine.

The organolead ant-iknock agents are ordinarily hydrocarb-olead compounds including tetraphenyllead, dimethyldiphenyllead, tetrapropyllead, dimet-hyldiethyllead, tetrarnethyllead and the like. Tetraethyllead is preferred as it is most commonly available as a commercial antiknock agent. It is also convenient in the case where organolead antiknock agents are employed to premix into a fluid the bis(cyclomatic nickel) acetylene compound, the organolead an-tiknock agent and supplementary agents, such as scavengers, antioxidants, dyes and solvents, which ffuids are later added to the liquid hydrocarbon fuel to be improved.

Where halohydrocalrbon compounds are employed as scavenging agents, the amounts of halogen used are given in terms of theories of halogen. A theory of halogen is defined as the amount of halogen which is necessary to react completely with the metal present in the antiknock mixture to convert it to the metal dihalide, as for example, lead dihalide. In other words, a theory of halogen represents two atoms of halogen for every atom of lead present. In like manner, a theory of phosphorus is the amount of phosphorus required to convert the lead present to lead orth-ophosphate, Pb (PO that is, a theory of phosphorus represents two atoms of phosphorus for every three atoms of lead. One theory of arsensic, antimony and bismuth is defined in the same general way. That is, one theory thereof is two atoms of the element per each three atoms of lead.

The hal-ohydrocarbon scavengers which can be employed in the compositions of this invention can be either aliphatic or aromatic halohydrocarbons tor a combination of the two having halogen attached to carbon in either the aliphatic or aromatic portion of the molecule. The scavengers may also be carbon, hydrogen and oxygen containing compounds, such as haloalkyl ethers, halohydrins, halo ethers, halonitro compounds, and the like. Still other examples of scavengers that may be used in the fuels of this invention are illustrated in US. Patents 1,592,954; 1,668,022; 2,398,281; 2,479,900; 2,479,901; 2,479,902; 2,479,903; 2,496,983; 2,661,379; 2,822,252; 2,849,302; 2,849,303; and 2,849,304. Mixtures of different scavengers may also be used and other scavengers and modifying agents, such as phosphorus compounds, may also be included. Concentrations of organic halide scavengers ranging from about 0.5 to about 2.5 theories I given in U.S. Patent 2,398,381.

, invention.

When used in the compositions of this invention, phosphorus, arsensic, antimony and bismuth compounds have the property of altering engine deposit characteristics in sevenal helpful Ways. Thus, benefits are achieved by including in the compositions of this invention one or more gasoline-soluble organic compounds of the elements of. Group VA of the periodic table, which elements have atomic numbers 15 through 83. The periodic table to which reference is made is found in Langes Handbook of Chemistry, 7th Edition, pages 58-59. One efiect of these Group VA compounds is to alter the deposits so that in the case of spark plugs the resulting deposits are less conductive. Thus, imparted to the spark plug is greater resistance to fouling. In the case of combustion chamber surface deposits, the Group VA element renders these deposits less catalytic with respect to hydrocarbon oxidation and thus reduces surface ignition. In addition, these Group VA elements in some Way inhibit deposit build up on combustion chamber surfaces, notably exhaust valves. This beneficial efiect insures excellent engine durability. In particular, excellent exhaust valve life is assured. Of these Group VA elements the use of gasoline-soluble phosphorus compounds is preferred from the oost-efiectiveness standpoint. Applicable phosphorus additives include the general organic phosphorus compounds, such as derivatives of phosphoric and phosphorus acids. Representative examples of these compounds include trimethylphosphate, ltrimethylphosphite, phenyldimethylphosphate, triphenylphosphate, tricresylphosphate, tri-B-chloropropyl thionophospha-te, tributoxyethy'lphosphate, xylyl dimethylphosphate, and other alkyl, aryl, aralkyl, alkaryl and cycloalkyl analogues and homologues of these compounds. Phenyldimethylphosphates in which the phenyl group is substituted with up to three methyl radicals are particularly preferred because they exhibit essentially no antagonistic effects upon octane quality during engine combustion. Other suitable phosphorus compounds are exemplified by dixyly-l phosphoramidate, tributylphosphine, triphenylphosphine oxide, t-ricresyl thiophosphate, cresyldiphenyl phosphate, and the like. Gasoline-soluble compounds of arsensic, antimony and bismuth corresponding to the above phosphorus compounds are likewise useful in this respect. Thus, use can be made of various alkyl, cycloaikyl, aralkyl, aryl land/or alkaryl, arsenates, arsenites, antimonates, antimonites, bismuthates, bismuthites, etc. Tricresyl arsenite, rtricumenyl arsenate, trioctyl antimonate, triethyl antimonite, d-iethylphenyl bismuthate and the like serve as examples. Other very useful arsensic, antimony and bismuth compounds include methyl arsine, rtrimethyl arsine, triethyl arsine, triphenyl arsine, arseno benzene, triisopropyl bismuth-inc, tripentyl stibine, tricresyl stibine, trixylyl bismuthine, tricyclohexyl bismuthine and phenyl dicresyl bismuthine. From the gasoline solubility and engine inductibility standpoints, or-

ganic compounds of these Group VA elements having up to about 30 carbon atoms in the molecule are preferable. Concentrations of these Group VA compounds ranging fnom about 0.05 to about one theory based on the lead normally sufiice. In other Words, the foregoing technical benefits are achieved when the atom ratio of Group VA element-to-lead ranges from about 0.123 to about 2:3.

A further embodiment of my invention comprises antiknock fluids containing [an organolead antiknock agent, a bis(cyclomatic nickel) acetylenic compound, and, optionally, a scavenger for the organolead compound. The quantities of nickel compound and scavenger present with respect to the quantity of lead present are the same as set forth in the preceding paragraphs in describing a hydrocarbon fuel containing these various components. Thus, thefluid can be blended with a hydrocarbon base fuel to i give the fuel compositions described above.

The following examples are illustrative of fuels and fluids containing organolead compounds in combination with various bis(cyclomatic nickel) acetylene compounds.

EXAMPLE XXI To 10-00 gallons of a gasoline containing 46.2 percent paraflins, 28.4 percent olefins, and 25.4 percent aromatics which has a final boiling point of 390 F. and an API gnavity of 59.0 and which contains three milliliters of tetraethyllead as 62Mix (1 theory of ethylene dichloride and 0.5 theory of ethylene dibromide) is added sufficient bis(cyclopentadienyl nickel) pentyne-l to give a nickel concentration of six grams per gallon.

EXAMPLE XXII To a typical aviation fuel having an API gravity of 64.4 and an end boiling point of 335 F. and which contains 8.0 grams of tetraethyllead and one theory of dibromobutane is added a mixture of bis(cyclopentadienyl nickel) pentyne-l and bis(cyclopentadienyl nickel) hexyne-3 in amounts such that two grams of nickel from the pentyne-l compound and one gram of nickel from the hexyne-3 compound are present in the finished fuel.

EXAMPLE XXIII A fluid for addition to gasoline is prepared by admixing tetraethyllead, bis(cyclopentadienyl nickel) hexyne-3 and trimethy lphosphate in amount such that for each gram of lead there is 0.01 gram of nickel and 0.1 theory of trimethylphosphate.

To demonstrate the etfectiveness of hydrocarbon fuels blended with bis(cyclomatic nickel) acetylene compounds according to the invention, tests 'were made on fuels to -Which no antiknock agent Was added and fuels which were blended in accordance with this invention. These tests were conducted according to the Research Method. The Research Method of determining octane number of a fuel is generally accepted as a method of test which gives a good indication of fuel behavior in full scale automotive engines under normal driving conditions and is the method most used by commercial installations in determining the value of a gasoline additive. The Research Method of testing antiknocks is conducted in a single cylinder engine especially designed for this purpose and referred to as the CFR engine. This engine has a variable compression ratio and during the test the temperature of the jacket Water is maintained at 212 F. and the inlet air temperature is controlled at =125 F. The engine is operated at a speed of 600 rpm. with a spark advance of 13 before top dead center. The test method employed is more fully described in Test Procedure D- 908-55 contained in the 1956 edition of ASTM Manual of Engine Test Methods for Rating Fuels. When tested in this manner, it is found that the addition of one gram of nickel per gallon as the compound, bis(cyclopentadienyl nickel) hexyne-3, causes a substantial increase in the octane number of a non-additive containing gasoline. Further tests which were performed using the Research Method involved the base reference fuels which contained both a lead antiknock and halohydrocarbon scavengers. To the reference fuels was added a typical compound of my invention, bis(cyclopentadienyl nickel) hexyne-3. In each case, a substantial gain in the octane number of the base fuel was noted.

These results are set forth in the following table. The i a fuel designated as A in the table comprised 40 percent by volume of toluene, 30 percent by volume of n-heptane, 20 percent by volume of diisobutylene, and 10 volume percent isooctane containing three milliliters of tetraethyllead per gallon as 62-mix. 62-mix is a commercial antiknock fluid comprising tetraethyllead, 1.0 theory of ethylt enedichloride and 0.5 theory of ethylene dibromide. The t 13 fuel designated as B is a commercial regular grade fuel containing three milliliters of tetraethyllead per gallon as 62-mix, and the fuels designated C, D, E and F are commercial premium grade fuels containing three milliliters per gallon of tetraethyllead as 62-mix.

Table I.Research Octane Number vs. Fuel Type Similar results are obtained using concentrations of the nickel additive up to grams of nickel for each gram of lead in the fuel. Also, good results are obtained using other of the nickel compounds of my invention as the antiknock additive.

As shown by the above data, a typical compound of my invention, bis(cyclopentadienyl nickel) hexyne-3, is a very effective supplemental antiknock. As in the case of most supplemental antiknocks, it is generally more effective as a supplement at low concentrations, and its eifectiveness is diminished as its concentration is increased.

Further tests were conducted in a slightly modified version of the single cylinder CFR engine described above. In the modified test version, the fuel is injected directly into the engine cylinder rather than being inducted via a carburetor. In addition, the fuel is continually recirculated prior to injection into the cylinder so as to minimize any precipitation of the additive from the fuel. In this modified test, the single cylinder CFR engine is operated under the following conditions:

When tested in the above manner in the modified CFR injector engine, the following results were obtained using reference fuel A as described previously with respect to Table I.

Table II Grams of Octane Additive nickel per number gallon Bis(cyclopentadienyl nickel) propyne.. 0 99.9 1.0 101. 4 Bis (cyclopentadienyl nickel) heXyne-3 0 99.8 0.2 110. 0

As shown by the above table, compounds of my invention prove extremely effective as supplemental antiknocks 14 when tested in the modified CFR injector engine. As will be noted by a comparison of Tables I and II, the modified injector engine rating is extremely sensitive. Consequently, the increase in octane number, noted in this type of test, is larger than would generally be observed in the Research Method used in establishing the data for Table I.

A further use for my compounds is in gas phase metal plating. In this application, the compounds are thermally decomposed in an atmosphere of a reducing gas such as hydrogen or a neutral atmosphere such as nitrogen to form metallic films on a sub-strate material. These films have a wide variety of applications. They may be used in forming conductive surfaces such as employed in a printed circuit, in producing a decorative effect on a substrate material, or in applying a corrosion-resistant coating to a sub-strate material.

The compounds of my invention also find application as additives to distillate fuels used in home heating, and as additives to lubricating oils and greases to impart improved lubricity characteristics thereto. Further, my compounds may be incorporated in paints, varnish, printing inks, synthetic resins of the drying oil type, oil enamels and the like to impart improved drying characteristics to such compositions. Other important uses of my compounds include their use as chemical intermediates in the preparation of metal-containing polymeric materials. Also, some of the metallic derivatives of my invention can be employed in the manufacture of medicinals and other therapeutic materials, as well as in agricultural chemicals such as, for example, fungicides, defoliants, growth regulants, and the like. In addition to the use of my compounds in reducing smoke and soot when used as additives in distillate fuels used in home heating, they are also useful as additives to jet fuels and diesel fuels in reducing smoke and soot.

Having fu-lly defined the novel compounds of my invention, their mode of preparation and their manifold utilities, I desire to be limited only within the lawful scope of the appended claims.

I claim:

1. Organometallic compounds represented by the formula;

QCECQ' CyNiNiCy in which Q and Q are selected from the group consisting of hydrogen and univalent hydrocarbon radicals containing from one to about 10 carbon atoms, Cy and Cy are cyclomatic hydrocarbon groups having 5 to about 13 carbon atoms each of which donates five electrons to the nickel atom for bonding, and each of the two nickel atoms in the molecule achieves the electron configuration of krypton.

2. The compounds of claim '1 wherein Q is hydrogen and Q is an alkyl group containing from one to about 6 carbon atoms.

3. The compounds of claim 1 wherein Q and Q are alkyl groups containing from one to about 6 carbon atoms.

. Bis(cyclopentadienyl nickel) acetylene.

. Bis(cyolopentadienyl nickel) propy-ne.

. BisQcyclopentadienyl nickel) hexyne-S.

. Bis(-cyclopentadienyl nickel) pentyne-l.

. Bis(cyclop-entadienyl nickel) butyne-2.

. Bis(cyclopentadienyl nickel) phenylacetylene.

10. A process comprising reacting a compound having the formula Cy Ni wherein Cy is a cyclomatic hydrocarbon group having 5 to about 13 car-bon atoms with an acetylenic compound having the formula:

QCECQ' wherein Q and Q are selected from the group consisting of hydrogen and univalent hydrocarbon radicals containing from one to about 10 carbon atoms.

11. Process for the preparation of bisQcyclopentadienyl nickel) acetylene, said .process comprising reacting nickelocene with acetylene.

12. Process for the preparation of bis(cyclopentadienyl V ocene with pentyne-l.

'15. Process for the preparation of bis(cyclopen-tadienyl nickel) butyne-Z, said process comprising reacting nickelocene with butyne-2.

16. Process for the preparation of bis(cyc1opentadienyl nickel) phenylacetylene, said process comprising reacting nickelocene with phe-nylacetylene.

References Cited in the file of this patent UNITED STATES PATENTS 2,875,223 Pedersen et a1. Feb. 24, 1959 2,898,359 Leedham et a1. Aug. 4, 1959 2,901,336 Brown Aug. 25, 1959 2,918,360 Lauer Dec. 22, 1959 OTHER REFERENCES Dubeck: J.A.C.S. Jan. 20, 1960, vol. 82, No. 2. Hubel et al.: J. Inorg. Nucl. Chem, March 1959, v0

V 9, pp. 204 to 210.

T iln'ey-B-assett et -al.: J.A.C.S., volume 81, Sept. 5, 1959, p. 4757-4758?

Claims (1)

1. ORGANOMETALLIC COMPOUNDS REPRESENTED BY THE FORMULA: