US2976303A - Process for the preparation of bis (cyclopentadienyl) manganese compounds - Google Patents

Description

PROCESS FOR THE PREPARATION OF BIS(CYCLO- PENTADIENYL) MANGANESE COMPOUNDS Hymin Shapiro, Detroit, Earl G. De Witt, Royal Oak, and Jerome E. Brown, Detroit, Mich, assignors to Ethyl Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Aug. 8, 1955, Ser. No. 527,125 3 Claims. (Cl. 260-429) This case relates to a process for the preparation of novel hydrocarbon manganese compounds.

Attendant with the development and evolution of the embodiment of the process of this invention is the re-.-

' action of manganese salt with a cyclomatic group HA metal halide. An example of this is the reaction of the manganese salt, such as manganous bromide, with'cyclopentadienyl magnesium bromide. It is found that when the group IIA metal halides are used, the reaction time j is greatly reduced due to the increased activity of the internal combustion engine for passenger car and heavy- 1 duty service, the petroleum industry has been continually called upon to effect improvements in the antiknock quality of hydrocarbon fuels. These improvements have, in general, been brought about by two distinct methods. One of these methods comprises improvements in refining operations, such as thermal and catalytic cracking and reforming or alkylating processes. The other method comprises the use of fuel additives to effect an increase in the antiknock qualities of the hydrocarbon fuels. Inasmuch as improvements in refinery techniques involve considerable capital expenditures, the use of fuel additives'has attained greater and more widespread ac: c'eptance as the more effective method, particularly from the economic standpoint. New organo manganese compounds have been discovered which exhibit a high anticyclomatic group IIA metal compounds.

An especially preferred embodiment in this invention is the process comprising reacting a manganese halide salt' with a cyclomatic group IIA metal halide. I It is found that when .this combination is employed, the hydrocarbon cyclomatic manganese compounds are produced in greater yields in shorter periods of time with less drastic reac" Of the different manganese halide salts employed, the manganous chloride is especially pre tion conditions.

ferred.

The cyclopentadienyl-type group II metal salts which are used in our process are prepared by reacting a cyclomatic compound with an alkyl or aryl group 11 metal wherein C H is methyclcyclopentadiene and C H represents the methylcyclopentadienyl radical. Other cyclomatic group II metal halides, such as cyclopentadienyl beryllium chloride, indenyl calcium iodide, ethylcycloe The alkyl or aryl group IIA metal halides used in the above preparation are made by the reaction of the group Il A metal halides with alkyl or aryl zinc compounds.

knock effect when employed in hydrocarbon fuels. The:

instant invention is concerned with providing a method for the synthesis of these novel hydrocarbon maganese compounds which are useful as additives to fuels and lubricating oils and which are also useful in the synthesis of other manganese compounds capable of improving combustion characteristics of hydrocarbon fuels and as additives to lubricating oils and greases.

It is, therefore, an object of our invention to provide a method for-the preparation of novel hydrocarbon manganese compoimds. It is also an object of this invention to provide'a process for the preparation of novel hydrocarbon manganese compounds which utilizes readily available manganese compounds as starting reagents. Another object of our invention is to provide a method for the preparation of the novel manganese compounds which embodies a process of reacting readily available manganese compounds with easily prepared cyclopentadienyl radical donors.

, The'cyclopentadienyl-type compounds used in our in V vention consist of acyclopentadienyl nucleus, the carbon skeleton of which can have other organic or hydrocarbon substituents thereon having up to 12 or more carbon atoms.

-. When a cyclomatic radical of the compounds of our invention is substituted with univalent aliphatic radicals,

these substituents can be radicals having from 1 to about 12 or more carbon atoms, selected from the group con sistingof alkyl, alkenyl, aralkyl and aralkenyl. Thus,

when these substituents are univalent aliphatic radicals,

The above and other objects are accomplished by pro 1 viding a process'for the preparation of novel hydrocarbon cyclopentadienyl-type maganese compounds, hereinafter called hydrocarbon cyclomatic manganese compounds, having the general formula wherein R and R can be the same or diflerent and are cyclomatic hydrocarbon radicals having from 5 to about 17 or more carbon atoms which embody a group of 5 carbons having the general configuration found in cyclopentadiene, said compound being further characterized in that the cyclomatic hydrocarbon radical is bonded to the manganese through the carbons comprising the cyclopentadienyl-group configuration, comprising reacting a manganese salt with a cyclomatic group II metal salt.

An embodiment of this invention is a process for the preparation of the above'described novel hydrocarbon cyclomatic manganese compounds which comprises reacting a manganese salt, such as MnSO, or Mncl with a "cyclopentadienyl group II metal halide. A'pre'ferred A they can be alkyl radicals, such as methyl, ethyl, 11,- propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butylyu-t amyl, the various positional isomers thereof as, for example, Z-methylbutyl; 1,1-dimethylpropyl; l-ethylpropyli like.

tenyl, A -isobutenyl, A -sec-butenyl, A -sec-butenyl, :A

pentenyl, A -penteny1, and the branched chain isomers f. thereof A -hexenyl, A -hexenyl, A -hexenyl, and, the, branched chain isomers thereof, including 3,3-.dimethyl-' and l-methyl-l- A -buteny1; -2,3dimethyl-A -buteny1; ethyl-A -pr'openyl; and the various isomers of heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetra fiecenyl, heptadecenyl, octodecenyl, 'ke.

a-phenylbutyl,

corresponding a? and finaphthylderivatiyes n Patented Mar. 21, 1961 g eicosenyl, and the When the organic radical substituted in the cyclm Y matic group is a univalent aliphatic radical, it can'be, an aralkyl radical such as, for example,benzyl, ufphenyl ethyl, p-phenylethyl, a-phenylpropyl, a-phenylisopropyh] a-phenylisobutyl, B-phenyl-tbutyl, Inf-f naphthylmethyl, 5 uaphthylmethyl, u (a {naphthyll propyl, a-(p'-naphthyl)isopropyl, 'y-(d-naphthyl-mutyl, a- (d-naphthyl)-isobutyl, B-(E-naphthyl)-sec-butyl, 1

amy 1 awmsds and the various positional isomers thereof, and the like. Other such aralkyl radicals include the a'-, 13-, and 7'- anthryl derivatives of alkyl radicals such as a'-anthrylmethyl, [3-(' '-anthryl)-ethyl, A-(p'-anthryl)-2 niethylamyl, and the like, and the corresponding alkyl derivatives of phenanthrene, fiuorene, acenaphthene, chrysene, pyrene, triphenylene, naphthacene, etc. aliphatic radical can be an aralkenyl radical such as a-' phenylethenyl, B-phenylethenyl, u-phenyl-A -propenyl, and

the phenylderivatives of the isomers of butenyl, penteny], heptenyl, and the like, up to about eicosenyl. Other such arylalkenyls include u-(a-naphthyl)-ethenyl, a-(fi'- naphthyU-ethenyl, a-(a-naphthyl) n -propcnyl, a-(a'- naphthyD-B-propenyl, a-(fi'-naphthyl)-isopropenyl, and the like. In addition, such aromatic derivatives of alkenyls, that is, aralkenyl radicals include derivatives of. phenanthrene, fiuorene, acenaphthene, chrysene, naphthacene, and the like.

When the organic radicals comprising the substituents' in the cyclomatic groups of the compounds of our invention are univalent alicyclic radicals, these can be radicals selected from the group consisting of cycloalkyl and cycloalkenyl radicals. Thus, such univalent alicyclic radicals can be cycloalkyl radicals such as, for example, cyclopropyl, cyclobutyl, cycloamyl, cyclohexyl, cyclononyl, cyclod'ecyl, cyclododecyl, cyclooctodecyl, cyclo cicosyl, and such cycloaliphatic radials as a-cyclopropylethyl, a-cyclobutylpropyl, and the like. Similarly, the alicyclic radical suhstituents can be cycloalkenyl radicals such as a-cyclohexylethenyl, a-cycloheptyl-n -propenyl,- B cyclooctyl A propenyl, a-mcthylene-fi-cyclododecylethyl, and the like.

When the organic radicals substituted in the cyclomatic groups of our compounds are univalent aromatic radicals, they can be selected from the group consisting-of aryland alkaryl radicals. Thus, these univalent aromatic radicals can be aryl radicals such as, for example, phenyl, naphthyl, anthryl, and the like, including the various mono valent radicals of such aromatics as indene, acenaphthene, fluorene, naphthacene, chrysene, and the like. Moreover, these univalent aromatic radicals can be alkaryl radicals such as, for example, tolyl; 3,5-xylyl; p-cumenyl; mesityl; ethylphenyl; 2-me'thyl-u-naphthyl; l-ethyl-fi-naphthyl, and the like.

Having amplydescribed the meaning of the termor ganic radical, the discussion with regard to cyclomatic radicals has been facilitated. As stated hereinabove; the cyclomatic groups of the compounds of the present in= vention can be represented by four general formulae; The first class of cyclomatic radicals can be represented by the general formula Rs 4 R4 wherein each of R ,R R R and R can be the sameor difierent and is selected from the group consisting of hydrogen and organic or hydrocarbon radicals having from about 1 to about 12 or more carbon atoms. Illust'rative examples of such cyclomatic radicals include cyclopentadienyl; methylcyclopentadienyl; 1,2-dimethyl'cyclo, pentadienyl; ethylcyclopentadienyl; 1,3,4-tripropylcyclopentadienyl; 1,55dipenty1cyclopentadienyl;- l-r'net'hyle3-tbutylcyclopentadienyl; isopropenylcyclopentadienyli, 1,2- di(A isobutenyl)-cyclopentadienyl; 1-methyl-3-'( A -pentenyl) cyclopentadienyl; 18 phenylethyl)-cyclopentadi enyl; cyclohexylcyclopentadienyl; phenylcyclopentadienyl; l-ethyl 3 (oz-methyl)-cyclopentadienyl; (o-tolyl)-cyclopentadienyl; acetylcyclopentadienyl; and the like.

The second type of cyclomatic radical is the indenyltype radical represented by the general formula The univalent' (III) wherein each of- R R R R R5,- R R R and R, can be the same or different and is selected from the group consisting of hydrogen and organic and hydrocarbon radicals having fronrl to about 12 or-more carbon atoms. Illustrative examplesof such radical's" include fluorenyl; 3 ethylfiuore'ny1; 4,5-dipropylflu'orenyl; Q-mcthylfluorenyl; ethenylfiuorenylj 4 benzylfiuorenyl;' l-m-tolylfiuorenyl, andthelike; v

The fourthtype ofcyclomatic radical, that is, a radical containing the cyclopentadienyl-moiety can be represented by the eneral formula wherein a and b can be the same or dilferc'nt and are small whole intcgers'including zero and excluding one the sum a+b being at least two, and wherein R is selected from the class. consisting of hydrogen andqorganic radicals; Thus,--when a is zero, each ofthecarbon atoms designated as 2 and, 3- haveattached thereto armonovalcnt. radical selected from" the class consisting of hydrogen: and organic radicals. Furthermore, the monovalent radicals so attached can-bethe same or different; The same discussion applies toeach of the carbon atoms designated as 4 and 5 when" b is zero. Illustrativeexamples' of'thistype er cyclomatic radical include 4,5,6,7-tetrahydroindeny1; 1,2, 3,4,-S,6,7,8 octahydrofluorenyl; 3-methyl4,5,6,7-tetrahydroindenyl, and the like.

Non-limiting examples of the compoundsof this inven tion in which the cyclomatic radical has theconfiguration shown in Structure I above are bis(cyclopentadienyl)manganese;

bis(methylcyclopentadienyl)manganese;

bis (ethylcyclopentadienyl) manganese;

his (propylcyclopentadienyl)manganese;

bis(butenylcyclopentadienyl)manganese} bis(t-butylcyclopentadicnyl)manganese;

his hexylcyclopentadienyl) manganese;

bis(cyclohexylcyclopentadienyl)manganese;

bis (heptylcyclopentadinyl)manganese} bis(d'ecylclopentadienyl)manganese;

bis(dodecylcyclopentadienyl)manganese;

bis(1,2,3,4-tetramethylcyclopentadiehyl)niaiiganese;

his( 1,2,3,4,5-pentamethylcyclopentadieiiyl) manganese;

his 1,l}dibutylcyclopentadienyl)manganese;

his'(1,2 dipropyl 3 cycloheiiyltiyclbpntadinyl)riian ganese;

. 5 bis(tolylcyclopentadienyl)manganese; bis( 1,3-diphenylcyclopentadienyl) manganese; bis(acetylcyclopentadienyl)manganese; cyclopentadienyl(methylcyclopentadienyl)manganese; cyclopentadienyl(indenyl)manganese,

and the like.

When there is only one organo or hydrocarbo substituent on the cyclopentadienyl ring, its position is not specified since, according to theory, the cyclopentadienyl ring or group is bonded to the manganese by five equivalent bonds running from each of the five carbons in the cyclopentadienyl ring to the manganese. Since all these bonds are equivalent and all five-carbons in the ring areequidistant from the manganese, it is immaterial to which of the five carbons a single substituent is attached. When, however, more than one substituent is attached to the cyclopentadienyl ring, the positions are given so as to indicate the relative positions of the diiferent substituents with respect to each other on the cyclopentadienyl ring.

Examples of compounds having the configuration of Structure II given hereinabove are bis(indenyDmanganese; bis( 3 methylindenyDmanganese; bis(3-ethenylindenyl)- manganese; bis(LB-dimethylindenyl)manganese; bis(l,3- diethylindenyDmanganese; bis( 1,7 diisopropylindenyl)- manganese; bis(l,2,3,4,5,6,7-heptamethylindenyl)manganese; (S-pheuylindenyl) (3 (Z-ethylphenyl)indenyl)manganese, etc. Examples of compounds having the configuration of Structure III above are bis(fluorenyl)manganese; bis(3- ethylfluorenyDmanganese; bis(4-propylfluorenyl)manganese; bis(2,3,4,7-tetramethylfluorenyl)manganese; and the like.

Examples of compounds having the configuration of Structure IV above are bis(4, 5, 6, 7-tetrahydroindenyl) manganese; bis(3-methyl-4,7-dihydroindenyl)manganese;

bis(Z-ethyl 3 phenyl-4,5,6,7-tetrahydroindenyl)manganese; bis(l,2,3,4,5,6,7,8 octahydrofluorenyl)manganese; bis(l,4,5,8-tetrahydrofiuorenyl) manganese, and the like. The general method of the instant invention for the preparation of the bis(cyclomatic) manganese compounds involves the reaction of active cyclomatic group II metal compounds, such. as cyclomatic magnesium halides, cyclo-' matic zinc halides, and the like, with a compound of manganese, such as a manganese salt. I

In general, vthe synthesis of bis(cyclomatic) manganese .compounds by the reaction of cyclomatic group II metal salts, such as cyclomatic magnesium halides with-manganese salts, such as manganous halides, has the advantage of being less hazardous than other methods of preparation. Additional advantages are the ease and smoothness with which the reaction proceeds and the good yields of product that are obtained Without resorting to drastic pressure of temperature conditions.

The manganese salts employed are salts of an organic or inorganic acid, preferably the respective, manganous salts. Examples of these manganese salts are manganous acetate, manganous benzoate, manganous carbonate, manganous oxalate, manganous lactate, manganous nitrate, manganous phosphate, manganic phosphate, manganous sulfate, manganous fluoride, manganous chloride, man- ;ganous bromide, manganous iodide, and the like. In addition, manganese salts of B-diketones, such as tris(2,4- pentanedione)manganese and tris(2,4-hexanedione)manganese may also be employed, as Well as manganese salts of B-keto esters, such as the manganese salts ofethylacetoacetate, and the like. An example of the process employed is the reaction of cyclopentadienyl magnesium halide with manganous halide to give bis(cyclopentadienyl)manganese. Cyclomatic group II metal halide com oxide (Mn O manganous sulfide (MnS), manganic suldischarging liquids and solids, gas inlet and outlet means, 1 temperature measuring devices, heating and. means, means for agitation, and means-forcondensing 6 a give bis-(cyclomatic)manganese compounds such pj bis(methylcyclopentadienyl)manganese, etc. I p I. Q

In the process of the present invention, as ,statedhe'reinabove,we react a cyclomatic group ll inetalvsaltfwi th .a manganese salt to form the bis(cyclOmatiQmanQan'Qqe 1 compound. When the cyclomatic group IIj netal used contain a mixture of cyclomatic groups, the prod- .uct will be a mixed cyclomatic manganesecompound. 1 That-is, there may be two different cyclomaticfgroups attached to one manganese atom. The reaction is preferably carried outin the presence of a suitable solvent, examples of which are hydrocarbonssuch as benzene, cyclohexane, diisobutylene, toluene; and ethers such as diethyl ether, ethylene glycol diethyl ether, propylene glycol methylphenyl ether, methylphenyl ether, tetrahydrofuran, dioxane, dodecyl ether, etc. In other words, hydrocarbon and ether solvents having up to about 20 carbon atoms may be employed. I f Y 3 The process of the instant invention is especiallys'uited to the preparation of cyclomatic manganese compounds in which at least one of the carbon-to-carbon double bonds in the cyclopentadienyl-group configuration of the cyclomatic radical is olefinic in nature; that is, not more than two carbons of the cyclopentadienyl ring should be shared with fused aromatic. ring, such as a benzene ring. An example of one of the substituted cyclomaticradicals of this preferred embodiment is the, indenyl radical When R, the cyclomatic radical, has this type of configufiltration, centrifugation, and the like. The product can J also be separated from the reaction mixture by vacuum distillation or selective solvent extraction. The solvent may be removed from the product by fractional distilla-. tion and the product further purified by fractional dis- I tillation or sublimation.- The method of preparation is further illustrated in the examples below. l

EXAMPLE I v v Bis(cyclopentadienyl)manganese A reaction vessel equipped with means of charging vapors'was flushed with prepurifie'd nitrogen} Then, whilemaintaining a nitrogen atmosphere,'there wasadd'ed to the vessel 14.6 parts of'magnesium turningsin 200' parts of dry diethyl ether. This was then followed'byQ the slow addition of 54.5 parts of ethyl bromide in 250 parts of ether, the addition being at such a rate that the contents of the reaction vessel refluxed slowly.- Reflux temperature was maintained for a period' of about one hour after the addition of the ethyl. bromide. The ether solution of the ethyl magnesium bromide, Grignard'solm' tion, was next added with stirringto a solution of3 6.7; parts of cyclopentadiene in parts of ether at room '1' temperature under an atmosphere of nitrogen in ayessel similar to the one described above. Cyclopentadienyl magnesium bromide was immediately 'formed,-with;.-.the evolution of ethane. Upon completion of the, addition of the Grignard reagent to the cyclopentadiene, the reaction mixture was maintained at reflux temperature f an additional period of about 20 hours.. ,To thereactidil mixture was then added 31 parts of manganous chloride and the contents of the vessel maintained at: reflux temperature. for a period of about 40 hours. Following this the ether wasremoved by distillation and the dry residue purifiedby fractional sublimation to give a good yield of bis(cyclopentadienyl) manganese. The bis(cyclopentadienyl)manganese was in the form of brown-black crystals which, on analysis, were found to contain 64.9% carbon and 5.44 hydrogen, corresponding'to the formula (C H Mn; calculated 64.9% carbon and 5.41% hydrogen. The bis(cyclopentadienyl)manganeseoxidizes readily in air and should; therefore, be kept in an inert atmosphere such as nitrogen.

EXAMPLE IIv Bi's(methylcyclopentadienyl) manganese Methylcyclopentadienyl calcium chloride is prepared in a manner analogous to that used for the preparation of cyclopentadienyl magnesium bromide in Example I, the procedure being carried out in tetrahydrofuran 'as a solvent. Reaction with manganous bromide produces a good yield of bis(methylcyclopentadienyl) manganese, a viscous reddish-brown liquid which crystallized on standing. Analysis shows theproduct to be 66.7% carbon and 6.54% hydrogen, corresponding to the formula (C HQ Mn; calculated 67.6% carbon and 6.62% hydrogen. I

EXAMPLE III Bis( indenyl )manganese Following the procedure of Example I a good yield of bis(indenyl)manganes'e is obtained by reacting cyclopentadienyl strontium iodide with manganous iodide in ethylene glycol dimethyl ether. Upon analysis the composition of the compound is found to correspond to the empirical formula (CgHq)2MIl.

EXAMPLE IV B is dodecylcyclopentadz' enyl manganese A reaction between dodecylcyclopentadienyl barium chloride and manganous sulfate according to the procedure of Example I gives a good yield of bis(dodccylcy- .clopentadienyhmanganese corresponding to the empirical formula (C 'H hMn.

Good results are also obtained when other manganese salts are employed as, for example, manganous nitrate,

m'anganous oxalate, manganous carbonate, etc.

EXAMPLE V Bis(phenylcyciopentadienyl)manganese Phenylcyclopentadi'ene, obtained by treating cyclopentenone with phenyl lithium to give 1-phenyl-2-cyclopentadiene-l-ol which, upon distillation, yields phenylcyclopentadiene, is. reacted with ethyl magnesium bromide according 'to the procedure described in Example Following the procedure of Example I, 3-cyclchexylindene is reacted with butyl strontium bromide followed by reaction. with tris(2,4-pcntanedione)rnanganese and bis(3-cyclohexylindenyl)manganese is obtained in good .y d-

. The temperature at which our process is carried outmay be varied depending on the solvent that is employed. It is usually found advantageous toconduct the reaction at the reflux temperature of the solvent and this is found to vary from 10 C. to about 200 C. The solvent need not be an ether; it may be an excess of the cyclopentadienyl (or cyclomatic) compound. The manganese salt, i.e., MnCl MnBR MnSO etc., may be added to the cyclomatic group II salt solution at temperatures ranging from -20 to about C. and higher depending on the boiling point of the solvent and, since there is no great temperature rise upon addition of the manganese salt, the temperature limits are not critical. However, we prefer to conduct this reaction at a tem perature of from 20 to about 65 C. in order to cut down the time of reaction. The reaction mixture need not be refluxed, however, reflux periods of up to 20 hours after the addition of the manganese salt to the reaction mixtures have been employed with good suce cess. The time of reaction of the manganese salt with the cyclomatic group II metal salt will vary depending on the metal employed as well as upon the complexity of the cyclopentadienyl radical and also on the particular salt that is used. It is found that when cyclopentadienyl group 11A metal halides are employed, the reaction proceeds with relative ease and higher yields are obtained.

Solvents other than those employed in the examples given hereinabove are used to good advantage. Such other solvents. or mixtures thereof are n-butyl ether, dioxane, toluene, ethylene, glycol ethers, etc.

In. the illustrative examples given above, nitrogen was employed. as. the inert atmosphere to prevent oxygen from coming in contact with the reactants. Other inert gases are also used with satisfactory results. Examples of such other gases are argon, methane, ethane, pro pane, and other hydrocarbons, as well as vapors of the solvents employed in the reaction. When nitrogen is used, it should preferably be prepurlfied so as to have a minimum of oxygen contamination.

The reaction conditions should be preferably anhydrous when carrying out the process of this invention. However, small amounts of water are tolerable although they may have a tendency to reduce the yield of desired product.

The compounds which are prepared by the process of our invention are useful in the synthesis of other manganese compounds which are also capable of improvingcombust'ion characteristics of hydrocarbon fuels. An example of such use is the preparation of methylcyclopentadienyl manganese tricarbonyl as described in the following example.

EXAMPLE VIII Methylcyclopentaa'ienyl manganese tricarbonyl Bis(methylcyclopentadienyl)manganese, prepared as described in Example 11, was added to a pressure resistant vessel under a nitrogen atmosphere and the vessel charged with carbon monoxide. The vessel and contents were then heated from 22 C. to about 148 C.

while maintaining the pressure in the reaction vessel hydrocarbon fuels used in spark ignition engines. The

use and preparation of these cyclopentadienyl manganese tricarbonyl compounds is more fully disclosed in our copending application Serial No. 521,364, filed July 11, 1955, now U.S. Patent No. 2,818,417

The cyclomatic compounds prepared by the prcc ess of the "present invention possess particular utility as additives. Thus, many of the cyclomatic derivatives can be used as fuel additives such as for fuels for in ternal combustion engines of both the spark ignition and compression ignition types, fuels for jet engines and rocket fuels, and the like. Likewise, many of the cyclematic compounds of the present invention can be successfully employed as additives to natural and synthetic lubricants as Well as the more viscous unctuous materials exemplified by natural and synthetic greases.

Other important uses of the cyclomatic compounds of the present invention include the use thereof as chemical intermediates, particularly in the preparation of metal and metalloid containing polymeric materials. In addition, some of the cyclomatic derivatives of this invention can be used in the manufacture of medicinals and other therapeutic materials as well as agricultural chemicals such as, for example, fungicides, insecticides, defoliants, growth regulants, and so on.

A particular advantage of the new compositions of matter of the present invention is the fact that by proper selection of the cyclomatic groups attached to the manganese, compounds having tailormade characteristics can be obtained. For example, compounds such as his- (cyc'lopentadienyl)manganese, cyclopentadienyl indenyl manganese, methylcyclopentadienyl indenyl manganese, bis(indenyl)manganese, will possess different degrees of stability, volatility, and solubility due to the varying complexity of the cyclomatic groups in the molecule. Likewise, the selection of the cyclomatic constituents enables the preparation of compounds of diverse applicability. This application is a continuation-in-part of our copending applications Serial No. 297,392, filed July 5, 1952,

and Serial No. 417,920, filed March 22, 1954, and Serial No. 325,224, filed December 10, 1952, now Patent No. 2,818,416.

Having fully described the novel cyclomatic derivatives of the present invention, the need therefor, and the best methods devised for their preparation, we do not intend that our invention be limited except within the spirit and scope of the appended claims.

radicals are bonded to the manganese through the car-' bons of the cyclopentadienyhgroup, comprising reacting, in proportions to produce said R Mn compounds and in an inert atmosphere, an ionic manganese salt with a compound having the formula RMX wherein M is a group II metal and X is halogen.

2. The process of claim 1 wherein said group 11 metal is a group IIA metal.

3. A process for the preparation of bis(cyclopentadienyl)manganese comprising reacting manganous chloride in an inert atmosphere at a temperature in excess of -20 C. with cyclopentadienyl magnesium chloride in proportions to produce said bis(cyclopentadienyl) manganese and separating the bis(cyclopentadienyl)manganese from the reaction product by fractional distillation.

References Cited in the file of this patent UNITED STATES PATENTS 2,012,356 Shappirio Aug. 27, 1935 2,272,133 Shappirio Feb. 3, 1942 2,434,578 Miller Jan. 13, 1948 OTHER REFERENCES Egerton et al.: Journal of Institution of Petroleum Technologists, February-December 1927, vol. 13, pages 244-255.

Kealey et al.: Nature, vol. 168, pages 103940, De-

cernber 15, 1951.

Claims (1)

1. A PROCESS FOR THE PREPARATION OF HYDROCARBON CYCLOMATIC MANGANESE COMPOUNDS HAVING THE GENERAL FORMULA R2MN WHEREIN R IS A CYCLOMATIC HYDROCARBON RADICAL SELECTED FROM THE GROUP CONSISTING OF THE CYCLOPENTADIENYL RADICAL AND HYDROCARBON SUBSTITUTED CYCLOPENTADIENYL RADICALS HAVING FROM 5 TO ABOUT 17 CARBON ATOMS WHICH EMBODY A GROUP OF 5 CARBONS HAVING THE GENERAL CONFIGURATION FOUND IN CYCLOPENTADIENE, SAID COMPOUND BEING CHARACTERIZED IN THAT THE CYCLOMATIC HYDROCARBON RADICALS ARE BONDED TO THE MANGANESE THROUGH THE CARBONS OF THE CYCLOPENTADIENYL-GROUP, COMPRISING REACTING, IN PROPORTIONS TO PRODUCE SAID R2MN COMPOUNDS AND IN AN INERT ATMOSPHERE, AN IONIC MANGANESE SALT WITH A COMPOUND HAVING THE FORMULA RMX WHEREIN M IS A GROUP II METAL AND X IS HALOGEN.