‘ amam‘ nited States Patent ‘"0 " Patented Aug. 26, 1958

1 2 It is an object of .this'invention to provide a new class 2,849,471 of organometallic compounds. A’ further object is to pro vide new~organometalliccarbonyl halide compounds of ORGANOMETALLIC CARBONYL HALIDE COM POUNDS OF A GROUP VIII METAL DIRECTLY ‘group VIII metals and processes for-their preparation. BONDED TO ONE CYCLOPENTADIENYL Other objects will appear hereinafter. NUCLEUS AND TO HALOGEN AND (IO-ORDI These objects are accomplished by the following inven -NATELY BONDED TO AT ‘LEAST TWO CAR tion of new organometallic compounds of group VIII BONYL GROUPS, AND THEIR PREPARATION metals of Mendeleef’slPeriodic Table in which the metal is’bonded to ‘at least two-carbonylrgroups and to at least John C. Thomas, Wilmington, Del., assignor to E. I. du 10 one halogen atom, >an'diis Ffurth'er bonded directly to a Pont de Nemours and Company, Wilmington, Deh, a carbocyclic hydrocarboniradicalcontaining one cyclopen corporation of Delaware tadiene ‘ring ‘through "nuclear {carbon of said ring. The .No Drawing. Application January 28, .1955 preferred class of compounds of thisinvention are those Serial No. 484,830 in which the‘metal isof-the *fourth‘period of group 'VIII of theIperiodic>table,-i. e.,ra-metalof'the iron family, and 17 Claims. 1(Cl.‘260-—439) 'isl-b'on‘de'd v‘to =;( a) va cyclopentadienyl rradical I‘ through nu clear ‘carbon thereof, ‘(12) two :carbonyl groups, and This invention relates to a new class of organometallic (c) i’halogenlo‘fa tornic number ‘1710135, i. e., chlorine derivatives and their preparation. Moreparticularly, this or'bromine. invention relates to new organometallic carbonyl‘halide "The'newloompounds of this‘invention arev generally ob derivatives of group'VIII metalsand processes ‘for their ‘.tained ?by 5the:halogenation, ‘either :with free ‘haogen or preparation. with ~a=mercuric halide:of,ve.=g., a cyclopentadienyl group Organometallic compounds, wherein the metal atom is VIII metal carbonyl. bonded directly to carbon of organic radicals,,hav.e "found Thef‘following-‘examples illustrate‘ speci?c embodiments utility in ‘catalytic and synthetic processes. ‘For example, 125 vof thei‘preparation-of the ~new'compouu'ds-of this inven tetraethyllead is used as an antiknock agent in'spark ig tion. nition engines; organomercury compounds are used in‘ the ‘EX’AMPBE ‘I fungicide ?eld, particularly as seed disinfecetants; and organomagnesium, organosodiurn and organolithium com :Prep‘aralion 0f cyclopenmu/ienylimn dicarbonyl chloride pounds are used inorganic syntheses. 'Carbonyls‘of'var by 1chl0i'inati0n 0f.7bis(cyclopentadienyliron) tetracar ious metals, and'in particular of those ofgroup "VIII, rlzanyl ' ‘ have found‘importance in-synthetic reactions-and as cat alysts. . Recently [Kealy and‘Paus-onjNature1168,'1039 ("1951) ] Theientirerpreparation as described below was carried "there has been disclosed a compound-"having‘two’cyclo out under a nitrogen atmosphere. A solution of ‘3.6 g. ‘pentadienyl radicals directly attached to ‘an ‘iron ‘atom. (0.05 mole) of chl0rine_in.5.0_ml.,of deoxygenated carbon This compound has beenconsidered unique "in'that, ac tetrachloride was added‘dropwise’with stirring to a solu cording to Wilkinson ‘et al. in I. Am. Chem. Soc. 74, . tion- of 117.7 rg.- (0.05tmole) {of :bis ( cyclopentadienyliron) ‘2125 (1952), all ?ve positionsof thecyclopenta'diene .tetraoarbonyl .in ‘.280 (ml. rot [methylene-chloride over a ring‘in dicyclopentadienylmetallics areiequivalent 'and‘no ‘.period. of .27 .:-minutes. ‘:The :temperature. of the ‘ mixture isomerism with respect to anyone cyclopentadiene ring was kept at 20-25 ° C. by periodicecooling with an ice is possible. Other group ‘VIII organometallics dicyclo bath. The mixturewasstirredfopBO minutes after com pentadiene have been‘reporte'd. 'For example, the- cobalt pletion of . the. addition. arid was pressure-?ltered. compound has been prepared by Wilkinsonj] ‘Chem. The-solid on-the'?lter vwa‘s'washed‘three times with de ‘Soc. 74, ’6146—9 (1952), and‘theniékelderivative-is the . . woxygenated -::ca.rb.on itetraehloride. 1The ?nal washings subject of my U. S.‘Patent2,‘680,‘758, issued June '8, 1954. were‘ colorless. 'll‘he: combined ?ltrate and'washings were "Wilkinson has also reported the preparation otcorre evaporated at-about 25.“3O1‘minutes. Themixture “pentadienyl radicals directly‘ linked through‘ carbonr‘there was pressure-?ltered; andithe solidwvas washed once with of to the metal atom. Many investigators‘ have attempted deoxygenated Water. tTheJcombined ?ltrate .aud'washing ‘to explain ‘the unusual stability of these lcompoun'ds-as were extracted with three successive 100.:ml. portions of I'due not only to the particular type of>organicradical methylene chloride. - bonded to the metal, but due also to the fact that there are , ‘The extractszwerexdried.oversanhydrous magnesium sul two: radicals 'so linked. . . fate ‘and evaporated at:room temperature or "below in a The preparation and properties of thegrouptVllli deriv "stream .of.;nit1'ogen. ‘:The residual, fred, crystalline solid :atives of cyclopentadienes are- not completely predictable. ‘ was ‘dried. furtherJ-at ?275 ° ‘l C:/ 2-5 mm. There was thus ob~ ‘As an example, dicyclopentadienyliron'has:been obtained :tained 118.‘. g. (38% yield) of ~nowiU.‘-S.1Patent?No...2;8l.0;73l6,iissued - QQtQbeIFZZ, 1957). i _ 2,849,471 , 3 4 EXAMPLE H pear as soon as the ?rst bromine was added. The solid was separated by ?ltration, washed with water, and dried. Preparation of cyclopentadienyliron dicarbonyl chloride There was obtained 14.5 g. of dicyclopentadienylcobalt by the reaction of bis(cycl0pentadienyliron)tetracar (III) tribromide. Recrystallization by dissolving the prod bonyl with mercuric chloride uct in methylene chloride and precipitating with benzene gave 10.5 g. of the tribromide. The monobromide as well as the corresponding triiodide are shown by Wilkinson, J. Am. Chem. Soc. 74, 6148 (1952). The entire preparation was carried out under nitrogen. The bis(cyclopentadienyliron) tetracarbonyl employed A solution of 32.6 g. (0.12 mole) of mercuric chloride in 10 300 ml. of deoxygenated, absolute ethanol was added in Examples I and II is prepared by the method of Catlin all at once to a solution of 42.6 g. (0.12 mole) of his ?led July 1, 1953, now Patent No. 2,810,736, issued (cyclopentadientyliron) tetracarbonyl in 900 ml. of de October 22, 1957, i. e., the reaction of iron petacarbonyl oxygenated, absolute ethanol with stirring at room tem at a temperature of preferably about 200° C. with cyclo pentadiene as follows: perature. The red color of the mixture lightened almost 15 immediately, and a crystalline precipitate came down. Ninety-eight grams (0.5 mole) of iron pentacarbonyl The mixture was stirred for 5 minutes at room tempera and 66 g. (1.0 mole) of cyclopentadiene in the form of its dimer were charged into a stainless steel bomb under ture and for 10 minutes at 40-45 ° C., chilled to 5° C., dry nitrogen. The bomb was closed, evacuated, vented and pressure-?ltered. with dry nitrogen to atmospheric pressure, and heated at The solid on the ?lter was washed two times with cold, 20 deoxygenated, absolute ethanol. This solid, which was 200° C. with rocking over a period of about 2 hours, crude chloromercuric derivative of cyclopentadienyliron and then allowed to cool to room temperature. The dicarbonyl hydride, could be puri?ed by recrystallization product was a dark brown mixture of a viscous liquid from deoxygenated, absolute ethanol. The combined ?l and a crystalline solid. The solid was broken up under 200 ml. of n-hexane, and the mixture was chilled in ice trate and washings were evaporated under about 25 mm. 25 and pressure-?ltered under dry nitrogen. The solid on pressure in a bath at 40-45” C. The residual, brick-red solid was shaken with 280 ml. of deoxygenated benzene, the ?lter was washed twice with cold n-hexane and dried and the mixture was pressure-?ltered. The solid on the in a stream of dry nitrogen. There was thus obtained 59 g. (67%) of a dark red, crystalline solid, which was ?lter was washed once with benzene. shown by analysis to be substantially pure bis(cyclopenta To the clear, dark red ?ltrate and washing was added 30 1120 ml. of deoxygenated n-hexane, and the mixture was dienyliron) tetracarbonyl. thoroughly chilled. The solid that precipitated was sep It will be understood that the above examples are arated by pressure ?ltration, washed three times with cold merely illustrative and that the invention broadly com hexane:benzene (4:1), and dried, ?rst in a stream of nitro prises the production of organometallic compounds in which a group VIII metal is co-ordinately bonded to at gen and then at 25° C./ 0.5 mm. There was thus obtained 35 18.5 g. (73% yield, based on the theoretical as per the least two carbonyl groups, co-valently bonded to a car equation) of a brick-red, crystalline solid having the same bocyclic hydrocarbon radical containing a cyclopenta physical properties as those of the product of Example I. diene ring through nuclear or ring carbon of said cyclo Analysis.—Calcd. for C5H5Fe(CO)2Cl: C, 39.59; H, pentadiene ring, and to halogen. These new com pounds have the formula RM(CO)mX,,, wherein R 2.37; CI, 16.69; Fe, 26.29. Found: C, 38.01; H, 2.49; 4:0 is the carbocyclic hydrocarbon radical containing a Cl, 18.12; Fe, 25.44. cyclopentadiene ring, M is a gorup VIII metal, X EXAMPLE III is a halogen and m is an integer of at least two Preparation of cyclopentadienyliron dicarbonyl bromide and n is an integer of at least 1 and their sum is from dicyclopentadienylcobalt(III) tribromide and the generally three. Thus, when m is 2 and n is 1, the form chloromercuric derivative of cyclopentadienyliron di 45 ula is RM(CO)2X, R being a carbocyclic hydrocarbon carbonyl hydride radical de?ned as aforesaid, particularly the cyclopen tadienyl radical, and M being a group VIII metal, partic ularly of the fourth period, i. e., the iron family, iron, cobalt and nickel. The entire preparation was carried out under nitrogen. 50 Although compounds where R is the cyclopentadienyl A solution of 4.3 g. (0.01 mole) of dicyclopentadienyl radical are particularly suited for reasons of availability cobalt(III) tribromide in 200 ml. of methylene chloride and reactivity, this invention is not so limited. Also in was added all at once to a solution of 4.1 g. (0.01 mole) cluded are those compounds where R is a carbocyclic of the chloromercuric derivative of cyclopentadienyliron hydrocarbon radical of ?ve to twelve carbons containing dicarbonyl hydride (prepared as in Example II) in 41 ml. 55 a cyclopentadiene ring. Examples of such hydrocarbon of methylene chloride. A solid precipitated immediately. substituted cyclopentadienyl radicals are those of 1,3 The mixture was allowed to stand for 5 minutes and diphenylcyclopentadiene and 1,3 - dimethylcyclopenta pressure-?ltered. diene. Radicals of polycyclic compounds, such as indene, The solid on the ?lter was washed two times with 3-phenylindene and 1,3-dimethylindene are also included. methylene chloride. The combined ?ltrate and washings 60 It is generally preferred that the compounds have sub were evaporated at about 25 mm. pressure at room tem stituents on no more than four of the nuclear carbons. perature. There was obtained, after complete removal of Particularly useful are carbocyclic hydrocarbons which solvent, about 2.5 g. of a brownish-red solid, which was contain 5 to 12 carbons and have a cyclopentadienyl soluble in organic solvents and slightly soluble in water. group. It is preferred that the carbocyclic hydrocarbon Analysis.--Calcd. for C5H5Fe(CO)2Br: C, 32.73; H, 65 radical be the unsubstituted cyclopentadienyl radical or 1.95; Br, 31.11; Fe, 21.74. Found: C, 32.33; H, 1.93; a hydrocarbon substituted cyclopentadienyl radical hav Br, 33.95; Fe, 20.79. ing at most one monovalent hydrocarbon‘ substituent, The dicyclopentadienylcobalt?II) tribromide of Ex preferably aliphatically saturated, of one to six carbon ample III Was obtained by treatment of dicyclopenta atoms, and most preferably lower alkyl groups. dienylcobalt(III) bromide with aqueous bromine as fol 70 The halogens which are particularly desired in the new lows: carbonyl halides of this invention are chlorine and bro Bromine was added dropwise with stirring, to a solu mine since they are cheap and readily available. How , tion of approximately 9.2 g. of dicyclopentadienylco ever, the other halides, i. e., the carbonyl ?uorides and balt(III) bromide in 230 ml. water until there appeared to iodides, are also useful and available. For example, cy be excess bromine present. A precipitate began to ap 75 clopentadienyliron dicarbonyl iodide can be obtained by sea-9,471 5 6 treatment of bis(cyclopentadienyliron) tetracarbonyl 4. Process for preparing cyclopentadienyliron dicar with iodine by the general method of Example I, or with bonyl chloride which comprises reacting mercuric chlo mercuric iodide by the general method of Example II. ride in solution with bis(cyclopentadienyliron) tetracar The iodide can also be obtained by treatment of the bonyl at a temperature of O to 50° C. chloromercuric derivative of cylopentadienyliron dicar~ 5. An organometallic carbonyl halide of a group VIII bonyl hydride with iodine. Cyclopentadienyliron dicar metal in which said metal is co-ordinately ‘bonded to each bonyl ?uoride can be obtained by the reaction of bis of at least two carbonyl groups and is further directly (cyclopentadienyliron) tetracarbonyl with mercuric bonded to halogen and to a carbocyclic hydrocarbon rad ?uoride. ical containing a cyclopentadiene ring through nuclear The compounds thus embraced by this invention have 10 carbon of said ring, said carbocyclic hydrocarbon radi a group VIII metal bonded directly to a carbocyclic hy cal containing not more than 12 carbon atoms. drocarbon radical containing the cyclopentadiene ring 6. An organometallic carbonyl halide of a group VIII through ring carbon thereof, and also have bonded to the metal in which said metal is co-ordinately bonded to each metal two carbonyl groups, i. e., two CO groups, and of at least two carbonyl groups and is further directly at least one halogen atom. Compounds speci?cally in 15 bonded to a cyclopentadienyl radical through nuclear cluded in the scope of this invention, in addition to those carbon thereof and to halogen. previously named, are methylclopentadienyliron dicar 7. An organometallic carbonyl halide of a group VIII bonyl bromide, phenylcyclopentadienyliron dicarbonyl metal in which said metal is of the iron family and is chloride, ethyl-cyclopentadienylnickel dicarbonyl bro coordinately bonded to each of two carbonyl groups and mide, cyclopentadienylcobalt dicarbonyl chloride, and 20 is further directly bonded to halogen and to a carbo the corresponding carbonyl halides of ruthenium, osmium, cyclic hydrocarbon radical containing a cyclopentadiene and platinum. Thus, the compounds of this invention ring through nuclear carbon of said ring, said carbocyclic contain a metal of Group VIII of the Periodic Table ac hydrocarbon radical containing not more than 12 carbon cording to Mendeleef, i. e., a metal of the iron family atoms with at most one monovalent hydrocarbon sub or a platinum metal. 25 stituent on its cyclopentadiene ring. The compounds of this invention are readily and prefer 8. An organometallic carbonyl halide of a group VIII ably obtained by the reaction of halogen, particularly metal in which said metal is of the iron family and is chlorine or bromine, upon a bis(hydrocarbon-substituted co-ordinately bonded to each of two carbonyl groups cyclopentadienyl group VIII metal) tetracarbonyl com and is further directly bonded to a cyclopentadienyl radi pound, or a bis(cyclopentadienyl group VIII metal) tetra 30 cal through nuclear carbon thereof and to halogen. carbonyl compound, such as. bis(cyclopentadienyliron) 9. An organoiron carbonyl halide in which iron is co tetracarbonyl, bis(cyclopentadienylnickel) tetracarbonyl, ordinately bonded to each of two carbonyl groups and bis(cyclopentadienylruthenium) tetracarbonyl, bis(cyclo is further directly bonded to halogen and to a carbo pentadienylosmium) tetracarbonyl or other similar group cyclic radical containing a cyclopentadiene ring through VIII metal carbonyls. This method is carried out in solu 35 nuclear carbon of said ring, said carbocyclic hydrocarbon tion, preferably in ahalogenated aliphatic hydrocarbon, radical containing no more than 12 carbon atoms with at a temperature of 0—50° C., and generally gives a purer . at most one monovalent hydrocarbon substituent on its product than other methods. cyclopentadiene ring. Another method involves the use of a mercuric halide 10. A cyclopentadienyliron dicarbonyl halide of the as illustrated in Example II while a further method em 40 formula ' ploys a chloromercuric derivative i. e., salt, of a cyclo RM(CO)2X pentadienylmetal carbonyl hydride to react-with an ionic wherein R is the cyclopentadienyl radical, X is halogen, dicyclopentadienylmetal halide as shown in Example 111. and M is iron which is co-ordinately bonded to each of These methods also can be carried out in solution at the two carbonyl (CO) groups and is further directly temperatures of 0 to 50° C. - 45 bonded to the cyclopentadienyl radical R through nu The compounds of this invention are particularly use clear carbon thereof and to halogen X. i ful as antiknock agents in spark ignition engines. They 11. Cyclopentadienyliron dicarbonyl chloride of the can also be used as catalysts for organic reactions, for formula example, in carbon monoxide reactions. The compounds react with alkali metal cyanides, such as potassium cya nide, to yield cyclopentadienylmetal compounds which 50 wherein C5H5 is the cyclopentadienyl radical and iron also contain carbonyl and cyano groups in addition to (Fe) is co-ordinately bonded to each of the two carbonyl the alkali metal. These products are useful as catalysts. (CO) groups and is further directly bonded to the cyclo They are water soluble. pentadienyl radical (C5l-I5) through nuclear carbon there of and to chlorine (Cl). As many apparently widely di?’erent embodiments of 55 this invention may be made without departing from the 12. Cyclopentadienyliron dicarbonyl bromide of the spirit and scope thereof, it is to be understood that this formula invention is not limited to the speci?c embodiments there of except as de?ned in the appended claims. wherein C5H5 is the cyclopentadienyl radical and ‘iron The embodiments of the invention in which an ex (Fe) is co-ordinately bonded to each of the two carbonyl clusive property or privilege is claimed are de?ned as (CO) groups and is further directly bonded to the cyclo follows: pentadienyl radical (C5H5) through nuclear ‘carbon there I claim: of and to bromine (Br). 1. Process for preparing a cyclopentadienyliron dicar 13. Process for preparing an organometallic dicar bonyl halide which comprises reacting a halogen in solu 65 bonyl halide which comprises reacting in solution, at a tion with bis(cyclopentadienyliron) tetracarbonyl at a temperature of 0 to 50° C., a halogenating agent selected temperature of O to 50° C. from the class consisting of halogen and a mercuric halide 2. Process for preparing cyclopentadienyliron dicar with a bis(carbocyclic metal) tetracarbonyl compound bonyl chloride which comprises reacting chlorine in so wherein said metal is from group VIII of the periodic lution with bis(cyclopentadienyliron) tetracarbonyl at a 70 table and said carbocyclic radical is hydrocarbon of not temperature of O to 501° C. more than 12 carbon atoms and contains a cyclopenta 3. Process for preparing a cyclopentadienyliron dicar diene ring bonded directly to said metal through nuclear bonyl halide which comprises reacting a mercuric halide carbon of said ring. in solution with bis(cyclopentadienyliron) tetracarbonyl 14. Process for preparing an organometallic dicar at a temperature of 0 to 50° C. V75 bonyl halide which comprises reacting in solution, at a 2,849,471 temperature of 0 to 50° C., a halogenating agent selected 16. Process for preparing a cyclopentadienylmetal di from the class consisting of halogen and a mercuric ha carbonyl halide which comprises reacting in solution, at lide with a.bis(carbocyclic metal) tetracarbonyl com a temperature of 0 to 50° C., a halogenating agent se pound wherein said metal is from the iron family of lected from the class consisting of halogen and a mer group VIII of the periodic table and said carbocyclic curic halide with a bis(cyclopentadienyl metal) tetracar radical is hydrocarbon of not more than 12 carbon atoms bonyl compound wherein said metal is from group VIII and contains the cyclopentadiene ring bonded directly to of the periodic table. said metal through nuclear carbon of said ring. 17. Process for preparing a cyclopentadienylmetal 15. Process for preparing an organoiron dicarbonyl dicarbonyl halide which comprises reacting in solution, halide which comprises reacting in solution, at a tempera 10 at a temperature of 0 to 50° C., a halogenating agent ture of 0 to 50° C., a halogenating agent selected from selected from the class consisting of halogen and a mer the class consisting of halogen and a mercuric halide with curic halide with a bis(cyclopentadienyl metal) tetracar a bis(carbocyclic iron) tetracarbonyl compound wherein bonyl compound wherein said metal is from the iron said carbocyclic radical is hydrocarbon of not more than family of group VIII of the periodic table. 12 carbon atoms and contains a cyclopentadiene ring bonded directly to iron through nuclear carbon of said No references cited. ring.

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