US3088962A - Acetylenic nickel compounds - Google Patents

Description

United States Patent 3,088,962 ACETYLENIC NICKEL COMPOUNDS Michael Dubeck, Royal Oak, Mich, assignor to Ethyl Corporation, New York, N.Y., a corporation of Virginia N0 Drawing. Filed Sept. 12, 1960, Ser. No. 55,180 10 Claims. (Cl. 260439) This invention relates to novel organometallic com pounds and their mode of preparation More specifically, this invention relates to bis(cyclomatic nickel) acetylenic compounds as hereinafter described.

An object of this invention is 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. Additional objects will become apparent by a reading of the specification and claims which follow.

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

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

In the above formula, at least one of the groups Z and Z, as described later, is an electron withdrawing group. The other Z substituent group can either be an electron withdrawing group or can be a monovalent substituent group which is unreactive with nickel and which is not an electron withdrawing group. Cy and Cy represent cyclomatic hydrocarbon groups which donate five electrons to the nickel atoms for bonding. By virtue of the electrons donated to each of the nickel atoms from the cyclomatic hydrocarbon groups, the acetylenic molecule, and the other nickel atom, each of the nickel atoms present in the molecule achieves the inert gas 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 con tains the cyclopentadienyl moiety. In general, such cyclomatic hydrocarbon groups can be represented by the formulae:

s Eli; R1 WERE] RP R R wherein the Rs are selected from the group consisting or hydrogen and univalent hydrocarbon radicals.

A preferred class of cyclomatic radicals suitable in the practice of my invention are those which contain from five to about 13 carbon atoms. These are exemplified by cyclopentadienyl, indenyl, methylcyclopentadienyl, propylcyclopentadienyl, diethylcyclopentadienyl, phenylcyclopentadienyl, tert-butyl cyclopentadienyl, p-ethylpheny) cyciopentadienyl, 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.

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 3,088,962 Patented May 7, 1963 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 at solid lines.

At least one of the substituent groups, Z or Z as shown in the above formula, is an electron withdrawing group. The other substituent group can also be an electron withdrawing group or can be a monovalent substituent group which is unreactive with nickel and further is not an electron withdrawing group. Typical of the electron withdrawing groups Z and/or Z are the following:

secn

In the above electron withdrawing groups, which are typical of Z and Z, R can be any group which does not react with the nickel reactant. Typically, R is a monovalent hydrocarbon group which may be an alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl, cycloalkenyl and the like. Typical of such groups are methyl, tert-butyl, cyclohexyl, propenyl, benzyl, p-methylphenyl and the like. Preferably, R does not contain more than 10 carbon atoms. X denotes a halogen group such as fluoro, chloro, bromo or iodo. When X is attached to a carbon atom which is in the alpha position relative to the triple bond of the bridging acetylenic compound, X is preferably fluorine. Since the fluorine atom is smaller than the other halogen atoms, it does not tend to sterically interfere with the reactivity of the acetylenic triple bond to the extent that larger halogen atoms do.

As indicated previously, when one of the Z substituent groups is an electron withdrawing group, the other Z substituent may be monovalent groups such as hydrogen, a monovalent organic group such as alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl, cycloalkenyl and the like which does not react with the nickel reactant and is not an electron withdrawing group. The groups may also contain non-hydrocarbon atoms such as in the case of a mercuro halide, a silyl, phosphine, arsine or stibinc group. Typical of such substituent groups which are not electron withdrawing groups are the lower alkyls, e.g. methyl,

ethyl, butyl, amyl and octyl; the aryls such as phenyl, anthracyl and the like; aralkyl groups such as benzyl, phenylbutyl, phenylheptyl and the like; alkaryl groups such as p-ethylphenyl, amylphenyl and heptylphenyl; alkenyl groups such as 3-buten-l-yl, 1-tridecen-13-yl, 2,4-butadien-1-yl and the like; cycloalkyl groups such as cycllohexyl, 4-methylcyclopentyl and cyclooctyl, and cycloalkenyl groups such as cyclopentadienyl, cyclohexenyl and the like. Preferably, the monovalent group is a hydrocarbon group and contains no more than 13 carbon atoms.

The novel compounds of my invention are formed according to the following reaction scheme:

ZCE CZ QCECQ' CyNiNiCy- As shown, my process involves a displacement reaction wherein one acetylenic molecule, ZCECZ, displaces another acetylenic molecule, QCECQ, from a bis(cyclo matic nickel) acetylenic reactant, QCECQ'CyNiNiCy'. As a result, there is formed a new bis(cyclomatic nickel) acetylenic compound having the formula ZCE CZ CyNiNiCy The above reaction is reversible. Thus, my process, in its broadest form, embodies the concept of displacing any acetylenic group with another acetylenic group from a compound QCEC-Q-CyNiNiCy wherein Q and Q are defined below and, in which the acetyleuic group bridges and is bonded to both nickel atoms in the manner described previously. The preferred embodiment of my process involves using as the displacing acetylenic group a compound ZCECZ as described above. This embodiment is preferred because, as will be described later, the acetylenic group ZCECZ reacts with nickelocene to form compounds having the formula ZCzCZ-CyNiNiCy. Thus, my preferred process aifords a way to make compounds ZCECZCyNiNiCy which cannot be made, except in low yield, by direct reaction of an acetylenic compound, ZCECZ', and a bis(cyclomatic) nickel com pound CyNiCy'.

The compounds formed by my process,

and the displacing acetylenic reactant, ZCECZ', are both described above. The bis(cyclomatic nickel) acetylenic reactant, QCECQ-CyNiNiCy, is defined in detail in my prior co-pending application Serial No. 852,216, filed November 12, 1959. As set forth in that application,

In this formula, Q and Q represent either hydrogen or univalent hydrocarbon radicals containing from one to about 10 carbon atoms. Cy and Cy represent cyclomatic hydrocarbon groups which donate five electrons to the nickel atoms for bonding. By virtue of the electrons donated 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 achieves the inert gas electron configuration of krypton.

As can be seen by comparing the structural formula of my novel organometallic compounds,

ZCE CZ CyNiNiCy with the structural formula of the organ-onickel reactant, QCECQ-CyNiNiCy, they are identical except for the difference in the acetylenic group which is bonded to and bridges the two nickel atoms in the molecule. The compounds, QCECQ-CyNiNiCy, as described in my prior application Serial No. 852,216, are formed by direct reaction of an acetylenic compound and a bis(cyclomatic) nickel compound. Surprisingly, the compounds of the present invention, ZCECZ-CyNiNiCy, are formed, if at all, in low yield by reaction of a bis(cyclomatic) nickel compound and an acetylenic compound, ZCECZ, in which at least one of the Z groups is an electron with drawing group. This is illustrated by reference to my prior co-pending application Serial No. 30,075, filed May 19, 1960, now abandoned, where there is described the reaction of a bis(cyclomatic) nickel compound with an acetylenic compound, ZCECZ, to give primarily a compound having the formula, CyNiCy-ZCECZ.

By virtue of the present invention, it is now possible to form binuclear cyclomatic nickel compounds,

in which Z or Z is an electron withdrawing group. The electron withdrawing substituent groups, Z or Z or both, on the bridging acetylenic molecule are reactive groups and thereby permit the use of the binuclear cyclomatic nickel-acetylenic compounds in a host of new applications. Because of the reactive nature of the substituent groups, Z and Z, my compounds can be utilized as intermediates in the preparation of nickel-containing polymers. Also, my compounds find great utility as intermediates in the preparation of new organic compounds.

My process is normally carried out in the presence of a solvent although in certain cases the acetylenic reactant, ZCECZ, may, if used in sufficient excess, serve as the solvent. In general, any unreactive solvent may be employed in which the bis(cyclomatic nickeD-acetylenic reactant is sufficiently soluble. Typical of such solvents are high boiling saturated hydrocarbons such as n-octane, n-decane, and other paratfinic 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 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 pentyl 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, glutaric, adipic, pimelic, suberic, azelaic, sebacic and pinic acids. Specific examples of such esters are (ii-(- ethylhexyl) adipate, di-(Z-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, the solvent should be selected so that it has a normal boiling point differing by at least 20 C. from the normal boiling point of the liquid product. Use of such a solvent enables separation of the product by means of distillation. If the product is a solid, the solvent should be selected so that its freezing point is sufficiently low to enable separation of the product therefrom by means of crystallization.

Although not critical, it is generally desirable to agitate the reaction mixture when carrying out my process. Agitation, especially if the reactants are not mutually soluble in the reaction solvent, insures a homogeneous reaction mass and an even reaction rate. Obviously, both conditions are desirable since they increase the efficiency of the process.

I generally employ a large excess of the acetylenic reactant, ZCECZ, in my process. The displacement reaction through which my process functions is reversible, and use of excess acetylenic reactant tends to force the reaction to completion. Further, the acetylenic reactant, ZCECZ', is generally cheaper than the nickel reactant, QCzCQ' CyNiNiCy. Thus, the presence of excess 'acet'ylenic reactant, ZCECZ, tends to force the reaction to completion so as to consume all of the nickel reactant, QCECQ-CyNiNiCy'. In some instances, such as when the displaced acetylenic moiety, QCECQ', is gaseous so that it can be readily removed from the reaction system, it is not necessary to employ an excess of the acetylenic reactant, ZCECZ'.

My process is generally carried out at a temperature from about zero to about 110 C. Preferably, however, my process is carried out from about 60 to about 80 C. since within this temperature range yields are maximized while undesirable side reactions are minimized. The pressure employed in my process is not critical and generally, the process can be conducted at atmospheric pressure. If desired, however, my process can be conducted under pressures up to about 100 atmospheres.

My process is preferably conducted in the presence of a blanketing atmosphere of an inert gas. Typical of such gases are krypton, neon, argon and the like. A preferred inert gas is nitrogen since it is relatively cheap and readily available. The function of the inert gas is to protect the reactants and products of my process against oxidation.

The product, ZCECZ-CyNiNiCy, formed in my proc ess can be separated from the reaction product by conventional means. Typical means of separation are chromatography and fractional crystallization.

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

Example I A mixture comprising two parts of bis(cyclopentadienyl nickel) acetylene and 1.5 parts of dimethyl acetylene dicarboxylate dissolved in 35.5 parts of tetrahydrofuran was charged to a reaction vessel that was equipped with a condenser which was connected through a protective drierite tube to a water-leveled gas measuring tube. After purging the reaction system thoroughly with nitrogen, the reaction mixture was heated at reflux for 18 hours. At the end of this time, the quantity of gas which had been evolved was 50 percent of that predicted by theory for displacement of all of the acetylene from the bis(cyclopentadienyl nickel) acetylene reactant. By this time, the reaction mixture had changed in color from a dark green to a dark brown. The reaction product was discharged and was reduced to one-half its volume by heating in vacuo. It was then diluted with an equal volume of petroleum ether, and a green-brown solid precipitate was formed. The mother liquor was decanted from the precipitate and cooled to 0 C. where a new precipitate formed. The mother liquor was again decanted and cooled to 40 C. at which point a third precipitate formed. The mother liquor was again decanted and cooled again to -40 C. to give a fourth precipitate. At this point, the remaining mother liquor was decanted and heated under reduced pressure to remove solvent and give a fifth isolated solid fraction. The first solid fraction was chromatographed on an alumina column using a :70 (volume ratio) mixture of benzene and petroleum ether as the solvent and eluant. The remaining fractions were chromatographed on similar columns employing pure benzene as both the solvent and eluant. By this procedure, there were isolated two fractions which differed considerably in polarity. The less polar material was bis(cyclopentadienyl nickel) acetylene, of which 1.0 part was recovered. The more polar green fraction, which exhibited strong absorption on alumina, was purified by recrystallization from low-boiling petroleum ether followed by sublimation at 60 C. and 0.05 mm. Hg. There was obtained 0.57 part of bis(cyclopentadienyl nickel) dimethyl acetylene dicarboxylate in the form of dark green crystals having a melting point of 103 C. On analysis, there was found: C, 49.6; H, 4.12 percent with a molecular weight, according to the Signer Method, of 384. Calculated for C H O Ni C, 49.3; H, 4.11 percent with a molecular weight of 390.

Example II A solution comprising one mole of bis(cyc1opentadienyl nickel) acetylene and 1.5 moles of diethylacetylcne dicarboxylate in toluene is charged to a reaction vessel under nitrogen. After heating for eight hours at 110 C. and atmospheric pressure, the reaction product is discharged. Excess solvent is stripped from the reaction product, and the residue is chromatographed on alumina using a 30:70 (volume ratio) benzene-petroleum ether mixture. A good yield of bis(cyclopentadienyl nickel) diethylacetylcne dicarboxylate is obtained from the eluate by means of fractional crystallization.

Example 111 A solution comprising 0.5 mole of bis(cyclopentadienyl nickel) propyne-l and 1.0 mole of diisopropylacetylene dicarboxylate in benzene is charged to a reaction vessel under nitrogen and heated for 15 hours at 30 C. at atmospheric pressure. The reaction product is then discharged, and a good yield of bis(cyclopentadienyl nickel) diisopropylacetylene dicarboxylate is obtained from the reaction product by means of chromatography followed by fractional crystallization of the cluate.

Example IV A solution comprising one mole of bis(cyclopentadienyl nickel) butyne-Z and one mole of dicyano acetylene in tetrahydrofuran is charged to a reaction vessel under nitrogen and heated for 10 days at 20 C. and atmospheric pressure. The reaction product is then discharged; solvent is removed by heating in vacuo, and the residue is dissolved in petroleum ether and chromatographed on alumina. A good yield of bis(cyclopentadienyl nickel) dicyano acetylene is recovered from the eluant by means of fractional crystallization.

Example V A solution comprising 0.1 mole of bis(cyclopentadienyl nickel) acetylene and 0.3 mole of dimethyl-4,4'-acetylenedibenzoate in diethylene glycol dimethyl ether solvent is charged to a reaction vessel under nitrogen and heated for 10 hours at 100 C. and atmospheric pressure. The reaction product is then discharged, and the compound, bis (cyclopentadicnyl nickel) dimethyl-4,4'-acetylenedibenzoate is recovered by means of chromatography followed by fractional crystallization.

Example VI A solution comprising 0.1 mole of bis(cyclopentadienyl nickel) hexyne-3 and 0.15 mole of dimethyl-octa-2,6-dien- 4-ynoate in benzene is charged to a reaction vessel under nitrogen and heated for 20 hours at C. and atmospheric pressure. The reaction product is then discharged; solvent is moved by heating in vacuo, and the residue is dissolved in a 30:70 (volume ratio) benzene-petroleum ether mixture and chromatographed on alumina. The eluate is then cooled repeatedly to yield the compound, bis(cyclopentadienyl nickel) dimethyl-octa-2,6 dien 4- ynoate by means of fractional crystallization.

Example VII A solution comprising 0.25 mole of bis(cyclopentadienyl nickel) pentyne-l and 0.3 mole of bis(m-methoxy phenyl) acetylene in diethyl ether is charged to a reaction vessel which is then pressurized with nitrogen. The reaction mixture is heated for 30 hours at 70 C. under a pressure of 80 p.s.i.g. with agitation. The reaction product is then discharged and the product, bis(cyclopentadienyl nickel) bis(m-methoxyphenyl) acetylene, is obtained by means of chromatography followed by fractional crystallization.

Example VIII A solution comprising 0.1 mole of bis(indenyl nickel) acetylene and 0.2 mole of perfluorobutyne-2 in isooctane solvent is charged to a reaction vessel which is then pressurized with nitrogen. After heating for 35 hours at 60 C. and a pressure of 50 p.s.i.g., the reaction product is discharged, and excess solvent is stripped therefrom. The residue is dissolved in a 30:70 (volume ratio) benzenepetroleum ether mixture and chromatographed on alumina. A good yield of bis(indenyl nickel) perfiuorobutyne-Z is obtained from the eluate by means of fractional crystallization.

My compounds can be used an antiknock agents in a liquid hydrocarbon fuel used in spark ignition internal combustion engines. For this use, Iemploy liquid hydrocarbon fuels of the gasoline boiling range containing from about 0.05 to about 10 grams per gallon of nickel as a compound of my invention. Preferred compositions are hydrocarbon fuels of the gasoline boiling range containing from about 1.0 to about 6.0 grams of nickel per gallon as a compound of my invention.

My compounds may be used as the sole antiknock agent in a liquid hydrocarbon fuel of the gasoline boiling range, or they may be present in addition to a conventional antiknock agent such as an organolead compound. Typical organolead compounds are tetraethyllead, tetramethyllead, dimethyldiethyllead, tetrapropyllead and the like. The fuels in which my compounds are employed may also contain such conventional additives as scavengers, antioxidants, and solvents, antiicing agents and the like.

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 substrate 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 substrate material.

The compounds of my invention also find application 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, my compounds 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.

Another use for my compounds is an additives to residual and distillate fuels, e.g., home heater fuels, jet fuels and diesel fuels, to reduce smoke and soot formation on combustion of the fuel. A still further utility for my compounds is as additives to solid propellants to control the burning rate.

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

I claim:

1. Organometallic compounds having the formula ZC E CZ CyNiNiCy' in which Cy and Cy are cyclomatic hydrocarbon groups having to about 13 carbon atoms and which are stable toward nickel, and Z and Z are selected from the group consisting of hydrogen, univalent hydrocarbon groups containing up to about 13 carbon atoms, and which are stable toward nickel, and electron withdrawing groups which are stable toward nickel and are selected from the class consisting of NEC- NEC:C:C

wherein R is a monovalent hydrocarbon group having up to 10 carbon atoms which is stable toward nickel, and X is a halogen radical, at least one of Z and Z being an electron withdrawing group.

2. Process for the formation of the compounds of claim 1, said process comprising reacting a compound having the formula QCECQ' CyNiNiCy' in which Cy and Cy are cyclomatic hydrocarbon groups having 5 to about 13 carbon atoms, and Q and Q are selected from the group consisting of hydrogen and univalent hydrocarbon groups containing from one to about 10 carbon atoms, with a compound ZCECZ' in which Z and Z are selected from the group consisting of hydrogen and univalent hydrocarbon groups having up to about 13 carbon atoms and which are stable toward nickel, and an electron withdrawing group which is stable toward nickel, selected from the class consisting of 0 ll RO-C NEG- acetylene clicarboxylate in a non-reactive organic solvent.

5. Process for the formation of his(cyclopentadienyl nickel) dimethyl acetylene dicarboxylate, said process comprising reacting bis(cyc1opentadienyl nickel) acetylene and dimethyl acetylene dicarboxylate in tetrahydrofuran.

6. The process of claim 2 wherein the solvent is tetrahydrofuran.

7. The process of claim 2 wherein the reaction temperature is within the range from about 0 to about 110 C.

8. Process comprising reaction bis(cyclopentadienyl nickel) acetylene and dimethylacetylene dicarboxylate in 10 tetrahydrofuran and separating the product, bis(cyclopentadienyl nickel) dimethylacetylene dicarboxylate.

9. The process of claim 2 wherein the groups, Q and Q, are hydrogen.

10. Bis(cyclopentadienyl nickel) dimethylacetylene dicarboxylate.

References Cited in the file of this patent Hubel et al., Journal of Inorganic and Nuclear Chemistry, vol. 9, pp. 204-206 (1959).

Tilney-Bassett, J.A.C.S., vol. 81, pp. 4757-8, Sept. 5, 1959.

Dubeck, J.A.C.S., vol. 82, No. 2, p. 502, Jan. 20, 1960.

Claims (1)

1. ORGANOMETALLIC COMPOUNDS HAVING THE FORMULA