Production of transition metal complexes

The invention relates to a process for the production of complex compounds of the transition metals which is characterized in that transition metals are reacted with magnesium, to which a catalytic quantity of anthracene and/or magnesium anthracene has been added as activator, in the presence of complexing ligands.

This invention relates to a general process for the synthesis of transition 
metal complexes by reacting transition metal compounds with specially 
activated magnesium in the presence of complexing electron donors. Several 
processes for the production of transition metal complexes using reducing 
alkali and alkaline-earth metals have been described, magnesium being 
particularly advantageous in terms of economy, non-toxic, safe handling 
and availability. 
Thus the reaction of nickel salts with particulate magnesium in the 
presence of triphenyl phosphane is described in as early a publication as 
DAS No. 11 26 864. However, the nickel complex formed through this 
reaction cannot be isolated, but instead is used in situ as a catalyst. 
DOS No. 14 43 461 describes the production of a nickel catalyst by 
reacting nickel compounds with inter alia magnesium metal in the presence 
of 1,3-dienes. No nickel-olefin complex is formed in this case either. The 
in situ reaction of nickel compounds with magnesium in the presence of 
phosphanes is also described in DOS No. 22 21 113, although no complex 
compound of nickel is characterized as such. These processes are clearly 
unsuitable for the production of transition metal complex compounds of 
defined composition. Italian Pat. No. 887,228 (C.A. 83, 28373) describes 
the production of bis(cyclo-(1,5)-octadiene) nickel from nickel halides 
and cyclo-(1,5)-octadiene by reaction inter alia with magnesium. However, 
the product is decomposable and requires the addition of stabilizers. 
However, pure storable substances are required for commercial applications. 
Klein and Karsch reported on the synthesis of 
tetrakis(trimethylphosphane)-cobalt (O) with magnesium metal as reducing 
agent in a reaction lasting 24 hours (H.-F. Klein and H. H. Karsch, Chem. 
Ber. 108, 944-955 (1975)). Finally, G. Wilke and W. Gausing used magnesium 
metal for the reductive synthesis of tris(butadiene)-molybdenum and 
-tungsten (Angew. Chem. 93, 201-202 (1981)). In this case, the reaction 
time was 48 hours. However, faster production processes are required for 
commercial applications. In addition, the reactivity of magnesium metal 
depends to a large extent upon the size and purity of its active surface 
(cf. for example J. R. Blackborrow, D. Young: "Metal Vapour Synthesis in 
Organometallic Chemistry", Springer-Verlag 1979 page 179). Hitherto, there 
has never been a satisfactory process for the economic production of 
transition metal complexes using magnesium as reducing agent. 
There has been no shortage of attempts to improve the reactivity of 
magnesium metal by the addition of activators and accelerators (cf. for 
example Y.-H. Lai, Synthesis 1981, 586). Accelerators and activation 
techniques such as these have also been occasionally used for the 
heterogeneous reaction of transition metal salts with magnesium. Thus, DOS 
No. 23 53 198 and DOS No. 23 53 240 describe a process for the production 
of a zerovalent nickel complex using inter alia magnesium and zinc halides 
or ammonium halides as accelerators in organic nitriles as solvents. For 
technical purposes, however, nitriles are generally uneconomical as 
solvents and the addition of foreign metal salts, such as zinc halides, 
complicates purification of the products. 
For the reduction of certain cyclopentadienyl transition metal halides with 
magnesium, M. D. Rausch and D. J. Sikora (J. Am. Chem. Soc. 103, 1265-1267 
(1981)) use mercury chloride as activator or employ a magnesium obtained 
from magnesium chloride using potassium metal (cf. R. E. Rieke et. al., J. 
Am. Chem. Soc. 96, 1775-1781 (1974)). These activation processes are 
highly involved when applied on a commercial scale and require the use of 
highly toxic mercury. 
It has now surprisingly been found that the addition of a catalytic 
quantity of anthracene and/or or magnesium anthracene to magnesium 
produces a highly active reducing agent which is as inexpensive as it is 
easy to handle and which generally enables transition metal compounds to 
be economically reacted in the presence of complexing ligands to form 
complex compounds of the transition metals. 
To produce the complex compounds by the process according to the invention, 
from 1 to 10 mole percent and preferably from 2 to 6 mole percent of 
anthracene is initially added to magnesium metal powder, which preferably 
has a particle size of less than 0.15 mm, in a solvent, preferably 
tetrahydrofuran or diglyms. Although the addition of an alkyl halide, such 
as methyl iodide, is favorable, it is not crucial to the process according 
to the invention. After 1 to 3 hours, a highly active magnesium is 
obtained in addition to a small quantity of magnesium anthracene and may 
be used for reduction of the transition metal salts in the presence of 
complexing ligands under mild conditions. In one variant of the process 
according to the invention, preformed magnesium anthracene is added as 
activator. Carrying out activation in an ultrasonic bath promotes the 
formation of a clean metal surface. According to the invention, the 
transition metal salts and the complexing ligands are contacted with the 
magnesium/anthracene system or magnesium anthracene at temperatures in the 
range from -78.degree. C. to + 150.degree. C. and preferably at 
temperatures in the range from -30.degree. C. to +80.degree. C., the 
reaction being accompanied by the evolution of heat and being complete 
within a few minutes to at most 3 hours. 
In this connection, it is important that anthracene or magnesium anthracene 
act as catalysts for the production of highly reactive Mg-species during 
reaction of the magnesium with the particular transition metal salts. The 
omission of these activation catalysts results in considerably poorer 
complex yields or in incomplete reduction of the starting product, as 
shown by comparison tests (cf. for example Examples 7, 8 and 29). As is 
typical of a catalyst, the readily separable anthracene may be recovered 
from the reaction mixtures and re-used (Example 22). 
Preferred transition metals are the elements of Groups IVB to VIIIB of the 
Periodic System of Elements, whilst preferred transition metal salts or 
compounds are those which contain either inorganic or organic anions, 
preferably those which are solvated in the systems used as solvent, such 
as halides, alcoholates and salts of organic acids. Examples of transition 
metals of Groups IVB, VB, VIB, VIIB and VIIIB of the Periodic System are 
titanium, zirconium, hafnium, vanadium, niobium, tantalum; chromium, 
molybdenum, tungsten; mangangese, technetium, rhenium; iron, cobalt, 
nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum. 
Suitable complexing agents are in general electron donors which form 
penetration complexes with transition metals. Electron donors such as 
these are compounds containing C--C-multiple bonds, such as olefins, for 
example ethylene, and also substituted olefins, such as methylene 
cyclopropane, stilbene, maleic acid anhydride or acrylonitrile, cyclic 
olefins, such as cyclopropene derivatives, norbornene, cyclic poly 
olefins, such as cyclooctadiene, cyclopentadiene and derivatives thereof, 
cyclododecatriene, and also polyolefins, such as allene, and conjugated 
olefin systems, such as 1,3-dienes (for example butadiene, isoprene, 
methylheptatriene), sorbic acid esters, also alkines, such as acetylene, 
2-butine, tolane, and cycloalkines, such as for example cyclododecine. 
Other suitable electron donors are ligands containing free electron pairs, 
such as phosphanes, phosphites, arsanes, triorganyl antimony compounds, 
pyridines and dipyridines, carbon monoxide and also combinations of 
various complexing agents. 
The process according to the invention enables magnesium, which is 
inexpensive, non-toxic and safe to handle, to be generally and effectively 
used for the first time for the production of transition metal complexes. 
In this connection, the following classes of complex compounds of the 
transition metals may be obtained with particular advantage using 
magnesium as reducing agent: .eta..sup.5 -cyclopentadienyl-transition 
metal complexes (metallocenes); .eta..sup.5 
-cyclopentadienyl-cobalt-olefin half-sandwich compounds which cannot be 
obtained in a single stage by known methods; .eta..sup.3 -allyl-complexes 
of the transition metals, preferably nickel and cobalt, in the presence of 
1,3-dienes; olefin complexes, particularly bis-(cyclooctadiene)-complexes 
and butadiene complexes of zerovalent transition metals, such as Ni, Pd, 
Pt and Mo; MTL.sub.n -complexes of the transition metals, MT representing 
a zerovalent transition metal, L a neutral ligand, such as phosphane or 
phosphite, and n being a number of from 2 to 5; metallocene dihalides, 
particularly .eta..sup.5 -cyclopentadienyl titanium dihalides. 
The complex compounds which may be inexpensively obtained in accordance 
with the present invention are used for example as catalysts in industrial 
chemistry (P. W. Jolly in: Ullmann's Enzyklopadie der Technischen Chemie, 
Vol. 16, pages 587 et seq.). Ferrocene is used as an addition in the 
low-smoke combustion of mineral oils. 
Cobaltocenes and cyclopentadienyl-cobalt half-sandwich complexes are used 
as catalysts in the production of pyridine derivatives from alkines and 
nitriles [cf. H. Bonnemann, Angew. Chemie 90, 517 (1978) and also U.S. 
Pat. No. 4,006,149 and DBP No. 2,840,460] and also in the production of 
pyridine derivatives (cf. Examples 16, 17, 18, 19, 20 and 21 of the 
present application). 
Bicycloocta-(1,5)-diene nickel is widely used in the synthesis of nickel 
complexes by ligand exchange [Inorg. Synth. XV, 5 (1974)] and as a 
catalyst in organic synthesis, especially in the production of natural 
substances [P. W. Jolly and G. Wilke; The Organic Chemistry of Nickel, 
Vol. II, Academic Press (1975), and also P. W. Jolly and G. Wilke in Merck 
Kontakte, 21, (1974)]. Tetrakis-triphenyl phosphane palladium is used as a 
catalyst in the functionalization of olefins [J. Tsuji in: Adv. in 
organomet. Chem. 17 (1979), pages 141 et seq.]. Phosphite complexes of 
nonvalent nickel enable butadiene to be catalytically hydrocyanated to 
form adipic acid nitrile on an industrial scale [Chem. Eng. News, Apr. 26, 
1971, 30; Chem. Week, May 12, 1971, 32-37]. In addition, metallocene 
dihalides, for example of titanium, are of interest as potential 
cytostatic agents (cf. H. Kopf and P. Kopf-Maier, Nachr. Chem. Techn. Lab. 
29 (1981), page 154).

EXAMPLE 1 
Cobaltocene 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyliodide 
are added to 14.4 g (600 mMoles) of magnesium powder (particle size &lt;0.15 
mm) in an inert gas atmosphere. A yellow-green solution is formed with 
stirring at 20.degree. C., orange-colored magnesium anthracene 
precipitating therefrom after about 2 hours. The reaction mixture is 
treated for about 3 hours in an ultrasonic bath (continuous peak HF output 
240 watts, 35 kHz) and then heated with stirring to 60.degree. C. After 
the addition of 19.8 g (300 mMoles) of monomeric cyclopentadiene, the heat 
source is removed and 35.6 g (100 mMoles) of solid cobalt-(III) acetyl 
acetonate are added over a period of 20 minutes. The reaction mixture 
changes color to dark brown with vigorous evolution of heat and begins 
refluxing (66.degree. C.). After cooling to 20.degree. C., the reaction 
mixture is filtered off from unreacted magnesium through a G-3-glass frit 
and the clear dark brown filtrate is concentrated by evaporation to 
dryness (max. bath temperature 30.degree. C.) in a high vacuum (10.sup.-3 
Torr). The residue is taken up in 500 ml of pentane and any undissolved 
fractions are isolated by filtration through a G-3-glass frit. The filter 
cake is washed several times with a total of 500 ml of pentane until the 
filtrate is substantially colorless. The clear red-brown filtrate is 
concentrated to approximately 200 ml and the complex is left to 
crystallize out at -80.degree. C. The supernatant mother liquor is removed 
under pressure and washed 2 to 3 times with approximately 50 ml of pentane 
cooled to -80.degree. C. Drying in vacuo (0.1 Torr) gives 12.4 g (63.7 
mMoles=63.7% of the theoretical) of pure cobaltocene in the form of 
black-violet crystals melting at 172.5.degree. C., as measured in an inert 
gas atmosphere. 
EXAMPLE 2 
Bis-(indenyl)-cobalt 
1.1 g (6.2 mMoles) of anthracene, 350 ml of THF and 0.1 ml of methyliodide 
are added to 14.4 g (600 mMoles) of magnesium powder (particle size &lt;0.15 
mm) in an inert gas atmosphere. A yellow-brown solution is formed while 
stirring at 23.degree. C., orange-colored magnesium anthracene 
precipitating therefrom after 100 minutes. The reaction mixture is treated 
for about 3 hours in an ultrasonic bath (continuous peak HF output 240 
watts, 35 kHz) and subsequently heated with stirring to 60.degree. C. 
After the addition of 34.8 g (300 mMoles) of indene, the heat source is 
removed and 35.6 g (100 mMoles) of solid cobalt-(III) acetylacetonate are 
added over a period of 40 minutes. The reaction mixture changes color to 
dark brown with an increase in temperature to 68.degree. C. After cooling 
to 23.degree. C., the reaction mixture is filtered off from excess 
magnesium through a G-3-glass frit and the clear brown red filtrate is 
concentrated by evaporation to dryness (max. bath temperature 30.degree. 
C.) in a high vacuum (10.sup.-3 Torr). The residue is taken up in 500 ml 
of pentane and any insoluble fractions are isolated by filtration through 
a G-3-glass frit. The filter cake is washed several times with a total of 
500 ml of pentane until the filtrate is substantially colorless. The clear 
red-brown filtrate is concentrated to approximately 200 ml and the complex 
left to crystallize out at -80.degree. C. The supernatant mother liquor is 
removed under pressure and washed 2 to 3 times with approximately 50 ml of 
pentane cooled to -80.degree. C. Drying in vacuo (0.1 Torr) gives 10.3 g 
(35 mMoles=35.5% of the theoretical) of bis-(indenyl)-cobalt in the form 
of glittering black crystals. 
EXAMPLE 3 
.eta..sup.5 -indenyl-.eta..sup.5 -cyclopentadienyl cobalt 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyliodide 
are added to 7.2 g (300 mMoles) of magnesium powder (particle size &lt;0.15 
mm) in an inert gas atmosphere. A yellow-brown solution is formed while 
stirring at 20.degree. C., orange-colored magnesium anthracene 
precipitating therefrom after about 2 hours. The reaction mixture is 
treated for about 3 hours in an ultrasonic bath (as in Example 1) and then 
heated with stirring to 60.degree. C. After the addition of 34.3 g (295.7 
mMoles) of indene and 7.7 g (116.7 mMoles) of monomeric cyclopentadiene, 
the heat source is removed and 35.6 g (100 mMols) of solid cobalt-(III) 
acetylacetonate are added over a period of 20 minutes. The reaction 
mixture changes color to dark red-brown with a vigorous heat effect 
(temperature up to 70.degree. C.). After cooling to 23.degree. C., the 
reaction mixture is filtered off from any insoluble fractions and from 
unreacted magnesium through a G-3-glass frit and the clear red-brown 
filtrate is concentrated in vacuo (10.sup.-2 Torr) until the sublimation 
of a red compound is observed. The vacuum is removed, the highly viscous, 
almost black residue is taken up in approximately 400 ml of pentane and 
any insoluble fractions are isolated by filtration through a G-3-frit. The 
filtrate is concentrated to dryness in a vacuum (10.sup.-1 Torr) and a 
scarlet-red compound is sublimated from the violet-brown residue in a high 
vacuum (10.sup.-3 Torr) at a bath temperature of 30.degree. to 150.degree. 
C. The sublimate is dissolved in approximately 100 ml of pentane, the 
resulting solution freed from any insoluble fractions through a G-3-frit 
and the clear, deep red filtrate is cooled to -80.degree. C. The 
supernatant mother liquor is removed under pressure from the complex 
formed and the crystals are washed twice with 25 ml of pentane cooled to 
-80.degree. C. Drying in vacuo (10.sup.-1 Torr) gives 4.2 g of .eta..sup.5 
-indenyl-.eta..sup.5 -cyclopentadienyl cobalt (17.6 mMoles=17.6% of the 
theoretical) of scarlet-red needles melting at 173.degree. C. 
Mass spectrum: m/e: 239 (M.sup.+); 174, 124; 59. 
EXAMPLE 4 
Ferrocene 
Following the procedure of Example 1, 0.6 g (3.4 mMoles) of anthracene are 
added to 3.6 g of magnesium powder in 300 ml of THF and the orange-colored 
reaction mixture is heated to 65.degree. C. After the addition of 19.8 g 
(300 mMoles) of monomeric cyclopentadiene, 16.2 g (100 mMoles) of 
FeCl.sub.3 are introduced over a period of 1 hour, the reaction mixture 
changing color to yellow-brown with vigorous evolution of heat. After 
cooling to 23.degree. C., the reaction mixture is concentrated to dryness 
in vacuo and the residue is extracted with a total of 500 ml of pentane. 
The dark yellow extract is cooled to -80.degree. C. and ferrocene is 
crystallized out. Drying in vacuo gives 12.9 g (69% of the theroetical) of 
ferrocene. 
EXAMPLE 5 
.eta..sup.5 -cyclopentadienyl cobalt cyclopentadiene 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyliodide 
are added with stirring in an inert gas atmosphere at 20.degree. C. to 7.2 
g (300 mMoles) of magnesium powder (particle size &lt;0.15 mm). After about 2 
hours, the reaction mixture is activated for about 3 hours in an 
ultrasonic bath (cf. Example 1). The mixture is then heated with stirring 
to 60.degree. C. After the addition of 52.8 g (800 mMoles) of monomeric 
cyclopentadiene, the heat source is removed and 35.6 g (100 mMoles) of 
solid cobalt-(III)-acetylacetonate are added over a period of 30 minutes, 
the reaction mixture changing color to deep red-brown with a vigorous heat 
effect (65.degree. C.). After cooling to 23.degree. C., the reaction 
mixture is filtered off from any insoluble fractions through a G-3-glass 
frit and the deep red-brown filtrate is concentrated to dryness (max. bath 
temperature 30.degree. C.) in vacuo (10.sup.-1 Torr). The residue is taken 
up in 500 ml of pentane and any insoluble fractions eliminated by 
filtration. The clear deep red filtrate is concentrated to dryness (max. 
bath temperature 30.degree. C.) in vacuo (10.sup.-1 Torr) and the residue 
sublimated at 10.sup.-3 Torr (bath temperature up to 60.degree. C., 
sublimation beginning at a bath temperature of 30.degree. C.). The 
sublimate is dissolved in approximately 100 ml of pentane and the complex 
crystallized out at -80.degree. C. 11.9 g (62.6 mMoles=62.6% of the 
theoretical) of .eta..sup.5 -cyclopentadienyl cobalt cyclopentadiene are 
obtained in the form of wine-red crystals melting at 98.degree. to 
99.degree. C. 
Mass spectrum: m/e: 190 (M.sup.+). 
EXAMPLE 6 
.eta..sup.5 -methylcyclopentadienyl cobalt methylcyclopentadiene 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyliodide 
are added in an inert gas atmosphere to 7.2 g (300 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-green solution is formed while 
stirring at room temperature, orange colored magnesium anthracene 
precipitating therefrom after about 2 hours. The reaction mixture is 
treated for about 3 hours in an ultrasonic bath (as in Example 1) and then 
heated while stirring to 60.degree. C. After the addition of 32.0 g (400 
mMoles) of monomeric methyl cyclopentadiene, the heat source is removed 
and 35.6 g (100 mMoles) of solid cobalt-(III)-acetylacetonate are added 
over a period of 30 minutes, the reaction mixture changing color to deep 
red-brown with a reflux-producing heat effect (65.degree. C.). After 
cooling to 23.degree. C., the reaction mixture is filtered off from any 
undissolved fractions through a G-3-glass frit and the deep red-brown 
filtrate is concentrated to dryness (max. bath temperature 30.degree. C.) 
in vacuo (10.sup.-1 Torr). The residue is taken up in 500 ml of pentane 
and any undissolved fractions are eliminated by filtration. The clear, 
deep red filtrate is concentrated to dryness (max. bath temperature 
30.degree. C.) in vacuo (10.sup.-1 Torr) and the residue distilled at 
10.sup.-3 Torr (bath temperature 80.degree.-140.degree. C.). 13.6 g (62.4 
mMoles=62.4% of the theoretical) of .eta..sup.5 -methylcyclopentadienyl 
cobalt methylcyclopentadiene are obtained in the form of a dark red oil 
which solidifies at around -5.degree. C. 
EXAMPLES 7 TO 21 
The use of anthracene-activated magnesium for the production of 
cyclopentadienyl cobalt diolefin half-sandwich derivatives is illustrated 
in the form of a Table in Examples 9 to 21. 
The procedure adopted is the same as in Example 1, anthracene initially 
being added to the magnesium, followed by ultrasonic treatment. The 
olefinic complex partners are then added together and the cobalt salts 
introduced into the mixture. Working up is carried out by changing the 
solvent from THF or diglyms to pentane. 
The following abbreviations are used in the Table. Examples 7 and 8 are 
comparison examples without anthracene. 
______________________________________ 
ac = acetate 
acac = acetylacetonate 
OEt = ethylate 
Cp = .eta..sup.5 -cyclopentadienyl 
CpH = cyclopentadiene 
Ind = .eta..sup.5 -indenyl 
Me = methyl 
t-but = tert-butyl 
COD = cycloocta-(1,5)-diene 
NBD = norbornadiene 
______________________________________ 
The complexes denoted by an asterisk are hitherto unknown products and are 
described after the Table. 
TABLE 1 
__________________________________________________________________________ 
Cyclopenta- 
Co-compound 
Reducing agent/ 
dienyl 
mMoles, addi- 
activator compound 
Olefin 
Solvent/ 
Yield 
No. Complex tion time 
mMoles/mMoles 
mMoles mMoles 
Temp. .degree.C. 
% 
__________________________________________________________________________ 
7 Ind Co COD 
CoCl.sub.2 
Mg act. with 
indene COD THF/30 
6.0 
100/30 mins. 
C.sub.1 - 104 
245 257 
8 Ind Co COD 
CoCl.sub.2 
Mg act. with I.sub.2 
indene COD THF/65 
19.2 
100/30 mins. 
100 250 250 
9 Ind Co COD 
CoCl.sub.2 
Mg/anthracene 
indene COD THF/65 
73.8 
100/20 mins. 
108/6.2 250 250 
10 Ind Co COD 
Co ac.sub.2 
Mg/anthracene 
indene COD THF/65 
80.5 
100/35 mins. 
200/6.2 250 250 
11 Ind Co COD 
Co acac.sub.3 
Mg/anthracene 
indene COD THF/65 
85.1 
100/40 mins. 
300/6.2 250 250 
12 Ind Co COD 
Co acac.sub.3 
Mg/anthracene 
indene COD THF/65 
51.0 
100/35 mins. 
300/6.2 110 110 
13 Ind Co COD 
Co acac.sub.3 
Mg/anthracene 
indene COD diglyms/ 
70.2 
100/30 mins. 
300/6.2 250 250 70-88 
14 Cp Co COD 
Co acac.sub. 3 
Mg/anthracene 
CpH COD THF/66 
79.1 
100/20 mins. 
300/6.2 111 250 
15 Cp Co COD 
Co(OEt).sub.2 
Mg/anthracene 
CpH COD THF/65 
45.1 
100/40 mins. 
400/7.5 250 250 
16* MeCpCoCOD 
Co acac.sub.3 
Mg/anthracene 
MeCpH COD THF/67 
71.1 
100/35 mins. 
300/6.2 110 250 
17* t-butCpCoCOD 
Co acac.sub.3 
Mg/anthracene 
t-butCpH 
COD THF/65 
41.7 
50/15 mins. 
150/3.1 57 125 
18.sup.++ 
Sime.sub.3 CpCoCOD 
Co acac.sub.3 
Mg/anthracene 
Me.sub.3 SiCpH 
COD THF/65 
70.0 
100/20 mins. 
300/6.2 110 250 
19* phenylCpCoCOD 
Co acac.sub.3 
Mg/anthracene 
phenylCpH 
COD THF/69 
approx. 40 
100/16 mins. 
300/6.2 90 250 
20* Sime.sub.3 IndCoCOD 
Co acac.sub.3 
Mg/anthracene 
Sime.sub.3 -indene 
COD THF/69 
50.6 
100/20 mins. 
300/6.2 115 250 
21* Ind Co NBD 
Co acac.sub.3 
Mg/anthracene 
indene NBD THF/69 
30.5 
100/40 mins. 
300/6.2 250 250 
__________________________________________________________________________ 
18.sup.++ The use of trimethylsilyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene as catalyst in the reaction of acetonitrile with 
acetylene: 
0.0458 g (0.1507 mMole) of trimethylsilyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene is dissolved in 114.2 g (2.785 moles) of 
acetonitrile and the resulting solution introduced under suction at room 
temperature into a 500 ml fine steel autoclave fitted internally with a 
coil condenser. The acetonitrile is saturated with acetylene at 18 bars, 
approx. 57.5 g (2.212 moles) of acetylene being added. The contents of the 
autoclave are then heated to 150.degree. C. over a period of 72 minutes 
during which the pressure rises to 46 bars. Increasing the reaction 
temperature to 212.degree. C. over a period of 160 minutes allows the 
pressure to rise to a maximum of 52 bars. After a total reaction time of 
312 minutes, the contents of the autoclave are internally cooled with 
water to 20.degree. C. over a period of 45 minutes. 
146.2 g of crude product are discharged from the autoclave and the volatile 
constituents removed by condensation at 10.sup.-3 Torr, 0.4 g of residue 
remaining behind. According to analysis by gas chromatography, the 
condensate (145.8 g) contains 80.88 g (1.973 moles) of acetonitrile, 52.58 
g (0.565 mole) of 2-picoline and 8.61 g (0.110 mole) of benzene, 
corresponding to a 39.4% 2-picoline solution in acetonitrile. The molar 
ratio of 2-picoline to benzene is 5.1:1 and the yield of 2-picoline, based 
on the acetonitrile reacted, amounts to 69.5%. Conversion: 29.2% of 
acetonitrile. Catalyst utilization: 3749 moles of 2-picoline/g-atom of 
cobalt or 5913.6 kg of 2-picoline/kg of cobalt. 
The use of trimethylsilyl cyclopentadienyl cobalt cycloocta-(1,5)-diene in 
the reaction of 2-cyanopyridine to form 2,2'-bipyridyl: 
0.0360 g (0.1190 mMoles) of trimethylsilyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene and 52.4 g (0.5038 mole) of 2-cyanopyridine are 
dissolved in 100 ml (87.9 g) of toluene and the resulting solution 
introduced under suction at room temperature into a 500 ml fine steel 
autoclave equipped with an internal coil condenser. The solution is 
saturated with acetylene at 16 bars, approximately 21 g (0.808 mole) of 
acetylene being added. The contents of the autoclave are then heated to 
150.degree. C. over a period of 45 minutes, during which the pressure in 
the autoclave rises to a maximum of 42 bars. The reaction temperature is 
increased to 202.degree. C. over a period of 120 mins. After a total 
reaction time of 165 minutes, the contents of the autoclave are internally 
cooled with water to 20.degree. C. over a period of 40 minutes. 
144.5 g of crude product are discharged from the autoclave and the volatile 
constituents are removed by condensation at 10.sup.-3 Torr, 1.0 g of 
residue remaining behind. According to analysis by gas chromatography, the 
condensate (143.3 g) contains 87.8 g of toluene, 41.0 g (0.394 mole) of 
2-cyanopyridine, 11.46 g (0.073 mole) of 2,2'-bipyridyl and 2.44 g (0.031 
mole) of benzene, corresponding to an 11.5% 2,2'-bipyridyl solution in 
toluene. The molar ratio of 2,2'-bipyridyl to benzene amounts to 2.4:1 and 
the yield of 2,2'-bipyridyl, based on the 2-cyanopyridine reacted, to 
66.4%. Conversion: 21.8% of 2,2'-bipyridyl. Catalyst utilization: 613 
moles of 2,2'-bipyridyl/g-atom of cobalt or 1632.2 kg of 2,2'-bipyridyl/kg 
of cobalt. 
*Characterization of the new compounds in Table 1: 
No. 16: Methyl-.eta..sup.5 -cyclopentadienyl cobalt cycloocta-(1,5)-diene; 
yellow-brown crystals melting at -15.degree. C. from pentane by 
concentration and crystallization at -80.degree. C. 
______________________________________ 
.sup.1 H--NMR (CDCl.sub.3, 80 Mhz) 
______________________________________ 
.delta. H.sub.1 4.58 (m) 
.delta. H.sub.2 4.27 (m) 
.delta. H.sub.3 3.22 (m) 
.delta. H.sub.4 2.34 (m) 
.delta. H.sub.5 1.57 (m) 
.delta. H.sub.6 1.55 (s) 
______________________________________ 
Mass spectrum: m/e: 246 (M.sup.+, 78%); 216 (90%); 138 (100%); 59 (53%). 
##STR1## 
Use as a catalyst: 
0.0364 g (0.1480 mMoles) of methyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene are dissolved in 119.0 g (2.902 moles) of 
acetonitrile and the resulting solution introduced under suction at room 
temperature into a 500 ml fine steel autoclave fitted with an internal 
coil condenser. The acetonitrile is saturated with acetylene at 15 bars, 
approximately 50.0 g (1.923 moles) of acetylene being added. The contents 
of the autoclave are heated to 140.degree. C. over a period of 30 minutes, 
during which the pressure rises to 48 bars. Increasing the reaction 
temperature to 180.degree. C. over a period of 72 minutes allows the 
pressure to rise to its maximum level of 48 bars. After a total reaction 
time of 120 minutes, the contents of the autoclave are internally cooled 
with water to 22.degree. C. over a period of 35 minutes. 
129.7 g of crude product are discharged from the autoclave and the volatile 
constituents are removed by condensation at 10.sup.-3 Torr, 0.1 g of 
residue remaining behind. According to analysis by gas chromatography, the 
condensate (128.2 g) contains 99.41 g (2.425 moles) of acetonitrile, 24.16 
g (0.260 mole) of 2-picoline and 3.74 g (0.048 mole) of benzene, 
corresponding to a 19.6% 2-picoline solution in acetonitrile. The molar 
ratio of 2-picoline to benzene is 5.4:1 and the yield of 2-picoline, based 
on the acetonitrile reacted, amounts to 54.3%. Conversion: 16.5% of 
acetonitrile. Catalyst utilization: 1757 moles of 2-picoline/g-atom of 
cobalt or 2766.8 kg of 2-picoline/kg of cobalt. 
No. 17* Tert-butyl-.eta..sup.5 -cyclopentadienyl cobalt 
cycloocta(1,5)-diene; dark brown crystals melting at 45.degree. C. After 
preliminary purification by sublimation at a bath temperature of 
80.degree. to 150.degree. C./10.sup.-3 Torr, the product is obtained from 
pentane at -80.degree. C.; highly sensitive to air in solution. 
Elemental Analysis: Observed: C: 70.93%; H: 8.62%; Co: 20.52%; Calculated: 
C: 70.82%; H: 8.74%; Co: 20.44%. 
______________________________________ 
.sup.1 HNMR 
(d.sub.8 -toluene, 80 Mhz) 
______________________________________ 
.delta.H.sub.1 
4.60 (t; J = 2.2 Hz) 
.delta.H.sub.2 
3.39 (t; J = 2.2 Hz) 
.delta.H.sub.3 .delta.H.sub.4 .delta.H.sub.5 .delta.H.sub.6 
##STR2## 
______________________________________ 
Mass spectrum: m/e: 288 (M.sup.+, 61%); 231 (93%); 229 (100%); 164 (54%); 
137 (28%); 125 (31%); 59 (47%). 
Use as a catalyst: 
0.0381 g (0.1321 mMole) of t-butyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene are dissolved in 116.25 g (2.835 moles) of 
acetonitrile and the resulting solution introduced at room temperature 
into a 500 ml fine steel autoclave fitted with an internal coil condenser. 
The acetonitrile is saturated with acetylene at 15 bar, approximately 54.0 
g (2.077 moles) of acetylene being introduced. The contents of the 
autoclave are heated to 150.degree. C. over a period of 54 minutes during 
which the pressure rises to 49 bars. Increasing the reaction temperature 
to 201.degree. C. over a period of 120 minutes allows the pressure to rise 
to a maximum level of 54.5 bars. After a total reaction time of 120 
minutes, the contents of the autoclave are internally cooled with water to 
25.degree. C. over a period of 45 minutes. 132.5 g of crude product are 
discharged from the autoclave and the volatile constituents are removed by 
condensation at 10.sup.-1 Torr, 0.4 g of residue remaining behind. 
According to analysis by gas chromatography, the condensate (132.0 g) 
contains 98.93 g (2.413 moles) of acetonitrile, 24.97 g (0.258 moles) of 
2-picoline and 4.55 g (0.0583 mole) of benzene, corresponding to a 20.2% 
2-picoline solution in acetonitrile. The molar ratio of 2-picoline to 
benzene is 4.6:1 and the yield of 2-picoline, based on the acetonitrile 
reacted, amounts to 63.5%. Conversion: 14.9% of acetonitrile. Catalyst 
utilization: 2032 moles of 2-picoline/g-atom of cobalt or 3203:8 kg of 
2-picoline/kg of cobalt. 
No. 19: Phenyl-.eta..sup.5 -cyclopentadienyl cobalt cycloocta-(1,5)-diene; 
analyzed by chromatography using a 70 cm long SiO.sub.2 column 
(eluent:pentane) and obtained in the form of copper-red flakes melting at 
64.3.degree. C. by crystallization from the eluent at -50.degree. C. 
Mass spectrum: m/e: 308 (M.sup.+, 98%); 278 (68%); 200 (100%); 141 (64%) 59 
(42%). 
Use as a catalyst: 
0.0403 g (0.1308 mMole) of phenyl cyclopentadienyl cobalt 
cycloocta-(1,5)-diene is dissolved in 116.3 g (2.115 moles) of 
propionitrile and the resulting solution introduced under suction at room 
temperature into a 500 ml capacity fine steel autoclave fitted with an 
internal coil condenser. The propionitrile is saturated with acetylene at 
14 bars, approximately 40.5 g (1.558 moles) of acetylene being introduced. 
The contents of the autoclave are heated to 130.degree. C. over a period 
of 72 minutes, the pressure rising to 42 bars. Despite an increase in the 
reaction temperature to 154.degree. C. over a period of 59 minutes, the 
pressure falls to 39 bars. After a total reaction time of 120 minutes, the 
contents of the autoclave are internally cooled with water to 20.degree. 
C. over a period of 30 minutes. 128.5 g of crude product are discharged 
from the autoclave and the volatile constituents removed by condensation 
at 10.sup.-3 Torr, 0.1 g of residue remaining behind. According to 
analysis by gas chromatography, the condensate (128.3 g) contains 103.9 g 
(0.226 mole) of propionitrile, 20.01 g (0.187 mole) of 2-ethylpyridine and 
2.60 g (0.033 mole) of benzene, corresponding to a 16.1% 2-ethylpyridine 
solution in propionitrile. The molar ratio of 2-ethylpyridine benzene 
amounts to 5.6:1 and the yield of 2-ethylpyridine, based on the 
propionitrile reacted, to 82.7%. Conversion: 10.7% of propionitrile. 
Catalyst utilization: 1430 moles of 2-ethylpyridine/g-atom of cobalt or 
2592.9 kg of 2-ethylpyridine/kg of cobalt. 
No. 20: Trimethylsilyl-.eta..sup.5 -indenyl cobalt cycloocta-(1,5)-diene; a 
deep red oil is obtained by evaporation from pentane and may be distilled 
at a path temperature of 130.degree.-190.degree. C./10.sup.-3 Torr, 
leaving a deep red, highly viscous oil. 
Elemental analysis: Observed: C: 67.84%; H: 7.66%; Co: 16.55%; Si: 7.86%; 
Calculated: C: 67.77%; H: 7.68%; Co: 16.63%; Si: 7.92%. 
Mass spectrum: m/e: 354 M.sup.+, (100%); 279 (63%); 246 (25%); 59 (17%). 
______________________________________ 
.sup.1 HNMR (d.sub.8 -toluene, 80 Mhz) 
______________________________________ 
.delta.H.sub.1 5.29 (d, J = 2.7 Hz) 
.delta.H.sub.2 3.97 (d, J = 2.7 Hz) 
.delta.H.sub.3 7.50 (m) 
.delta.H.sub.4 7.08 (m) 
.delta.H.sub.5 3.50 (m) 
.delta.H.sub.6 3.03 (m) 
.delta.H.sub.7 2.08 (m) 
.delta.H.sub.8 1.35 (m) 
.delta.H.sub.9 0.34 (s) 
______________________________________ 
.sup.13 CNMR (d.sub.8 -toluene) 
______________________________________ 
.delta.C.sub.1/2 68.43 
.delta.C.sub.2/1 66.09 
.delta.C.sub.3/4 31.55 
.delta.C.sub.4/3 31.29 
.delta.C.sub.5 78.78 
.delta.C.sub.6 94.51 
.delta.C.sub.7 78.87 (s) 
.delta.C.sub.8/9 108.81 (s) 
.delta.C.sub.9/8 108.53 (s) 
.delta.C.sub.10/13 
125.04 
.delta.C.sub.13/10 
124.72 
.delta.C.sub.11/12 
123.61 
.delta.C.sub.12/11 
123.52 
.delta.C.sub.14 -0.13 
______________________________________ 
##STR3## 
##STR4## 
______________________________________ 
Use as a catalyst: 
0.0746 g (0.2108 mMole) of trimethylsilyl indenyl cobalt 
cycloocta-(1,5)-diene is dissolved in 117.6 g (2.868 moles) of 
acetonitrile and the resulting solution introduced under suction at room 
temperature into a 500 ml fine steel autoclave fitted with an internal 
coil condenser. The acetonitrile is saturated with acetylene at 15 bars, 
approximately 52.0 g (2.000 moles) of acetylene being introduced. The 
contents of the autoclave are heated to 90.degree. C. over a period of 20 
minutes during which the pressure rises to 34 bars. Increasing the 
reaction temperature to 170.degree. C. over a period of 82 minutes allows 
the pressure to rise to a maximum level of 38 bars. After a total reaction 
time of 142 minutes, the contents of the autoclave are internally cooled 
with water to 21.degree. C. over a period of 45 minutes. 
146.3 g of crude product are discharged from the autoclave and the volatile 
constituents are removed by condensation at 10.sup.-3 Torr, 0.4 g of 
residue remaining behind. According to anlaysis by gas chromatography, the 
condensate (145.6 g) contains 87.31 g (2.130 moles) of acetonitrile, 46.69 
g (0.502 mole) of 2-picoline and 7.38 g (0.095 mole) of benzene, 
corresponding to a 34.8% 2-picoline solution in acetonitrile. The molar 
ratio of 2-picoline to benzene amounts to 5.3:1 and the yield of 
2-picoline, based on the acetonitrile reacted, to 67.9%. Conversion: 27.8% 
of acetonitrile. Catalyst utilization: 2381 moles of 2-picoline/g-atom of 
cobalt or 3754.1 kg of 2-picoline/kg of cobalt. 
No. 21: .eta..sup.5 -indenyl cobalt norbornadiene; from pentane by cooling 
to -80.degree. C. The supernatant mother liquor is removed under pressure 
from the complex which has crystallized out and the crystals are washed 
twice with 50 ml of pentane cooled to -80.degree. C. Drying in vacuo 
(10.sup.-1 Torr) gives red-brown needles melting at 58.degree. C. 
Elemental analysis: Observed: C: 72.32%; H: 5.52%; Co: 22.12%; Calculated: 
C: 72.19%; H: 5.64%; Co: 22.15%. 
______________________________________ 
.sup.1 HNMR 
(d.sub.8 -toluene, 80 MHz) 
______________________________________ 
.delta.H.sub.1 
7.14 (s) 
.delta.H.sub.2 
5.75 (t, J = 2.0 Hz) 
.delta.H.sub.3 
4.03 (d, J = 2.0 Hz) 
.delta.H.sub.4 .delta.H.sub.5 .delta.H.sub.6 
##STR5## 
______________________________________ 
Mass spectrum: m/e: 266 (M.sup.+, 95%); 239 (24%); 174 (50%); 150 (97%); 
115 (100%); 59 (40%). 
EXAMPLE 22 
Regeneration of the anthracene catalyst 
11 g (62 mMoles) of anthracene, 3000 ml of THF and 1 ml of methyliodide are 
added to 72 g (3.00 moles) of magnesium powder (particle size &lt;0.15 mm) in 
an inert gas atmosphere. A yellow-green solution is formed while stirring 
at 23.degree. C., orange-colored magnesium anthracene precipitating 
therefrom after about 2 hours. The reaction mixture is then activated for 
about 3 hours in an ultrasonic bath, followed by heating with stirring to 
65.degree. C. After the addition of 270 g (2.5 moles) of cyclooctadiene 
and 290 g (2.5 moles) of indene, the heat source is removed and 356 g 
(1.00 mole) of solid cobalt-(III)-acetylacetonate are introduced over a 
period of 30 minutes, the reaction mixture changing color to deep red 
brown with a vigorous heat effect (up to 73.degree. C.). After cooling to 
23.degree. C., the reaction mixture is filtered off from any insoluble 
fractions and from excess magnesium through a G-3 -glass frit and the 
clear red brown filtrate is concentrated to dryness (max. bath temperature 
40.degree. C.) in a high vacuum (10.sup.-3 Torr). The residue is taken up 
in 2.times.3000 ml of hot toluene and the resulting solution is filtered 
off while still hot from any insoluble residues. The filter cake is washed 
in portions with a total of 500 ml of hot toluene. Oxygen is passed 
through the clear, deep red-brown filtrate to oxidize the complex, 
followed by another hot filtration step. The solution of aromatics is then 
chromatographed at 60.degree. C. through a 60 cm Al.sub.2 O.sub.3 -column 
(activity stage 4) and the toluene evaporated in vacuo. Recrystallization 
from xylene gives 7.6 g of anthracene corresponding to 69% of the catalyst 
used. 
Mass spectrum: m/e: 178 (M.sup.+). 
EXAMPLE 23 
.eta..sup.3 -methylheptadienyl cobalt butadiene 
Following the procedure of Example 1, 2.4 g (100 mMoles) of magnesium 
powder are activated with 1.1 g (6.2 mMoles) of anthracene in 200 ml of 
THF and the orange colored reaction mixture cooled to -40.degree. C. After 
the addition of 200 g (3700 mMoles) of liquid 1,3-butadiene, 13.0 g (100 
mMoles) of solid Co-(II) chloride are introduced over a period of 60 
minutes, during which the color of the reaction mixture changes via 
grey-green to grey-brown with a slight increase in temperature (max. 
-34.degree. C.). After stirring overnight at -40.degree. C., the reaction 
mixture is cooled to -80.degree. C. and filtered off from any insoluble or 
precipitated fractions at -80.degree. C. The clear brown filtrate is 
concentrated in a high vacuum (10.sup.-3 Torr) at -80.degree. C. to 
-30.degree. C., the residue is taken up in 150 to 200 ml of ethanol and 
the complex is crystallized out at -90.degree. C. to -100.degree. C. The 
supernatant mother liquor is removed under pressure and the crystals are 
washed twice with 20 ml of pentane cooled to -100.degree. C. Drying in a 
high vacuum (10.sup.-3 Torr) at -30.degree. C. gives 13.5 g (60.9 
mMoles=60.8%) of methylheptadienyl cobalt butadiene. 
Mass spectrum: m/e: 222 (M.sup.+). 
EXAMPLE 24 
Bis-cycloocta-(1,5)-diene nickel-(O) 
7.2 g (300 mMoles) of magnesium powder are evacuated together with 1.1 g 
(6.2 mMoles) of anthracene (Mg:Ant=48:1) and placed in an atmosphere of 
argon. After suspension in 300 ml of THF dried over LiAlH.sub.4, 0.1 ml of 
ethyl bromide is added. After a few minutes, the solution becomes 
yellow-green in color and orange-colored magnesium anthracene soon begins 
to precipitate. The reaction is normally over after 3 hours. The 
suspension is cooled to 0.degree. C. and 61 ml (54 g-500 mMoles) of 
cycloocta-(1,5)-diene and approximately 15 ml of liquid butadiene are 
siphoned in with stirring, followed by the addition of 12.96 g (100 
mMoles) of solid anhydrous nickel chloride. The suspension soon becomes 
dark in color and is left to react overnight while cooling with ice. 
Hardly any heat effect is observed. 
The solution, which has meanwhile become deep violet in color, is freed 
from excess magnesium by filtration through a D-4-frit and 2 washes with 
50 ml of THF (reweighed quantity of Mg approx. 3.5 g), followed by cooling 
for 3 hours to -80.degree. C. The fine yellow crystals are filtered off at 
-80.degree. C. by means of a D-4-jacket frit and rinsed twice with a 
little THF and pentane. They are then completely freed from the deep 
violet solution and the pale yellow color of the Ni(COD).sub.2 becomes 
visible. The product is dried for 30 minutes at 23.degree. C. in an oil 
pump vacuum and subsequently transferred to a suitable vessel. (This 
intermediate isolation is not absolutely essential). Yield: 21.0 g. 
For purification and for complete separation from the NiCl.sub.2, the 
Ni(COD).sub.2 is recrystallized. To this end, it is transferred to a 
medium-sized D-4-frit, approximately 200 ml of toluene heated to 
40.degree. C. are added and, after stirring, the solution is rapidly 
introduced under pressure into a receiver cooled at .+-.0.degree. C. The 
rewashing operation may have to be repeated 1 to 2 times until the 
crystals are substantially dissolved. The filtrate is cooled for 2 hours 
at -80.degree. C., the resulting crystals are filtered off through a 
D-4-frit at -80.degree. C., washed twice with a little pentane, dried and 
transferred. Yield: 16.5 g of fine lemon-yellow flakes of Ni(COD).sub.2 
=60% of the theoretical (based on NiCl.sub.2). 
Elemental analysis: Observed: C: 69.89%; H: 9.06%; Ni 21.12%; Calculated: 
C: 69.86%; H: 8.79%; Ni 21.34%. 
EXAMPLE 25 
Bis-cycloocta-(1,5)-diene platinum 
Following the procedure of Example 1, 0.49 g (20 mMoles) of Mg are 
activated with 71 mg (0.4 mMole) of anthracene in 50 of THF, the orange 
colored reaction mixture is heated to 65.degree. C., 16.2 g (150 mMoles) 
of 1,5-cyclooctadiene are added and solid platinum-(II)-chloride is 
introduced over a period of 20 minutes. The reaction mixture becomes 
red-brown in color with a vigorous heat effect (up to max. 79.degree. C.). 
After cooling to 23.degree. C., the reaction mixture is concentrated to 
dryness in a high vacuum (10.sup.-3 Torr) and the residue is extracted 6 
times with 100 ml of toluene. The brown solution is filtered through an 
Al.sub.2 O.sub.3 -column (5 cm deactivated with 7% of H.sub.2 O) and the 
filtrate is concentrated in vacuo to approximately 30 ml. The mother 
liquor is removed under pressure from the light colored deposit 
precipitated, followed by washing with cold toluene. 
Bis-cycloocta-(1,5)-diene platinum is obtained in a yield of 3.7 g (9 
mMoles=45%). 
Mass spectrum: m/e: 410 (M.sup.+); 302. 
EXAMPLE 26 
Bis-cycloocta-(1,5)-diene palladium 
Following the procedure of Example 1, 0.6 g (25 mMoles) of Mg are activated 
with 90 mg (0.5 mMole) of anthracene in 60 ml of THF and the 
orange-colored reaction mixture is cooled to -40.degree. C., followed by 
the addition of 35 ml of cycloocta-(1,5)-diene and 1 ml of 1,3-butadiene. 
7.1 g (25 mMoles) of solid cycloocta-(1,5)-diene palladium dichloride are 
then introduced over a period of 30 minutes. After 1 hour, all the 
volatile constituents are rapidly distilled off from the dark reaction 
mixture in a high vacuum (10.sup.-3 Torr) at -40.degree. C., the residue 
is taken up in 100 ml of pentane (to which 5 ml of butadiene have been 
added) and the resulting solution filtered through an Al.sub.2 O.sub.3 
-column (5 cm) cooled to -30.degree. C. Concentration of the filtrate 
gives 1.2 g=15% of the theoretical of product which may be purified by 
further recrystallization. 
EXAMPLE 27 
Tris-(butadiene)-molybdenum 
Following the procedure of Example 1, 1.5 g (0.84 mMole) of anthracene are 
added to 3.3 g (135.8 mMoles) of magnesium in 500 ml of THF, followed by 
activation in an ultrasonic bath. The mixture is then cooled to 
-30.degree. C. and 23 ml of liquid butadiene are siphoned in. The 
hydrolysis-sensitive MoCl.sub.5 (9.8 g=35.8 mMoles) is introduced into the 
mixture over a period of 30 minutes in an inert gas atmosphere, initiating 
a highly exothermic reaction. The reaction mixture turns brown in color 
even in this short time. The THF is evaporated off at -10.degree. 
C./10.sup.-2 Torr and the solid residue is dried at 20.degree. 
C./10.sup.-2 Torr. After concentration by evaporation, extraction with 
toluene gives a tacky crude product which is re-extracted with 100 ml of 
pentane and recovered by cooling. After dissolution in another 30 ml of 
THF at 50.degree. C., the solution is cooled to -20.degree. C. The 
addition of 80 ml of cold ether produces 3.7 g (40% of the theoretical) 
of (C.sub.4 H.sub.6).sub.3 Mo. 
EXAMPLE 28 
Tetrakis-triphenylphosphane palladium 
Following the procedure of Example 1, 0.48 g (20 mMoles) of magnesium 
powder are activated with 0.1 g (0.45 mMole) of anthracene in 40 ml of THF 
and the orange colored reaction mixture is heated to 65.degree. C., 
followed by the addition of 21.0 g (80 mMoles) of triphenyl phosphane. 6.1 
g (20 mMoles) of solid Pd acac.sub.2 are then introduced over a period of 
20 minutes. The complex precipitates from the dark orange reaction mixture 
with evolution of heat (up to 69.degree. C.). After cooling to 23.degree. 
C., the crystals are filtered off through a G-3-frit and washed with 30 ml 
of pentane. Drying in vacuo (10.sup.-1 Torr) gives 20.6 g (17.9 
mMoles=89.5% of the theoretical) of yellow crystalline product melting at 
116.degree. C. 
EXAMPLE 29 
Reduction of Pd acac.sub.2 with Mg in the absence of activator 
240 mg (10 mMoles) of magnesium powder are suspended in 40 ml of THF and 
the resulting suspension treated for 2 hours in an ultrasonic bath, 
followed by the addition of 10.5 g (40 mMoles) of triphenylphosphane. 
After heating to 65.degree. C., 3.05 g (10 mMoles) of solid 
palladium-(II)-acetylacetonate are introduced over a period of 10 minutes, 
the reaction mixture becoming light brown in color. After stirring for 6 
hours at 65.degree. C., a pale yellow compound precipitates. After 
cooling, the deposit is filtered off and washed with 20 ml of ether, 
giving 5.9 g of a pale yellow triphenyl phosphine palladium 
acetylacetonate compound. 
Elemental analysis: Observed: Pd: 13.00%; P 9.40%. 
Infra-red spectrum: Acetylacetonate bands: 1655; 1550; 1350; 1232 cm.sup.-1 
; Triphenylphosphine bands: 1480; 1430; 1180; 1150; 1090; 1020; 995; 510 
cm.sup.-1. 
EXAMPLE 30 
Bis-(triorthotolylphosphite) nickel ethylene 
Following the procedure of Example 1, 2.4 g (100 mMoles) of magnesium 
powder are activated with 1.1 g (6.2 mMoles) of anthracene in 300 ml of 
THF and the orange colored reaction mixture is cooled to 0.degree. C. 
After the addition of 70.5 g (200 mMoles) of triorthotolylphosphite, 
ethylene gas is introduced through the mixture for 10 minutes and 25.7 g 
(100 mMoles) of solid nickel-(II)-acetylacetonate are introduced while 
ethylene gas is continuously passed through. Despite external cooling with 
ice, the internal temperature rises to 15.degree. C. The reaction mixture 
is left to react for 3 hours while ethylene is passed through and is then 
filtered off from any insoluble fractions through a G-3-frit. The 
yellow-brown filtrate is concentrated to dryness in vacuo (10.sup.-1 Torr) 
and the glassy-brittle residue is taken up in 300 ml of pentane and 100 ml 
of toluene. The solution is filtered off from any insoluble residues and 
the product is crystallized out by the addition of 100 ml of methanol. 
Crystallization is completed by cooling to B -20.degree. C. Yield: 51.5 
g=65% of the theoretical of yellow crystals melting or decomposing at 
118.degree. C. 
EXAMPLE 31 
Tris-(triorthotolylphosphite) nickel 
Following the procedure of Example 1, 1.44 g (60 mMoles) of magnesium 
powder are activated with 0.66 g (3.7 mMoles) of anthracene in 180 ml of 
THF. After the addition at 23.degree. C. of 70.5 g (200 mMoles) of 
triorthotolyphosphite, 15.4 g (60 mMoles) of solid 
nickel-(II)-acetylacetonate are introduced over a period of 20 minutes. 
The reaction mixture is freed from volatile constituents in vacuo 
(10.sup.-2 Torr) and the residue is taken up in 200 ml of pentane and 70 
ml of toluene. The solution is filtered off from any insoluble residues 
and 150 ml of methanol are added to the filtrate, followed by cooling to 
-20.degree. C., the complex precipitating in the form of light red 
crystals. Yield: 50.2 g=75% of the theoretical. 
EXAMPLE 32 
Pentamethyl-.eta..sup.5 -cyclopentadienyl cobalt bis-ethylene 
Following the procedure of Example 1, 8.3 mg (0.047 mMole) of anthracene in 
8 ml of THF are added to 48.2 mg (2.01 mMoles) of fine magnesium powder, 
followed by additional activation in an ultrasonic bath. Gaseous ethylene 
is passed through the solution at 0.degree. C. and 893.8 mg (1.99 mMoles) 
of [(Co(C.sub.5 Me.sub.5)I.sub.2).sub.2 ] are added all at once. The 
initially green-black suspension changes into an orange-brown solution 
which is evaporated at up to 25.degree. C./0.1 Torr. The residue is taken 
up in 8 ml of pentane, filtered and cooled to -80.degree. C. After a 
while, orange colored crystals of Me.sub.5 CpCo(C.sub.2 H.sub.4).sub.2 are 
obtained in a yield of 373.1 mg, corresponding to 75% of the theoretical. 
EXAMPLE 33 
Bis-(pentamethyl-.eta..sup.5 -cyclopentadienyl) zirconium dicarbonyl 
Following the procedure of Example 1, 10.1 mg (0.057 mMole) of anthracene 
in 25 ml in 25 ml of THF are added to 72 mg (2.96 mMoles) of fine 
magnesium powder, followed by additional activation for 5 hours in an 
ultrasonic bath. CO is the introduced, steps having to be taken to ensure 
thorough intermixing. 869.2 mg (2.01 mMoles) of (.eta..sup.5 C.sub.5 
Me.sub.5).sub.2 Zr Cl.sub.2 are then introduced and the mixture left to 
react for 2 hours. The dark red solution is concentrated by evaporation to 
dryness and the residue is taken up in 50 ml of pentane. The solution is 
filtered off from suspended particles. 696.1 mg (83% of the theoretical) 
of (.eta..sup.5 C.sub.5 Me.sub.5).sub.2 Zr(CO).sub.2 in the form of black 
needles are obtained at -30.degree. C. from the solution concentrated to 
20 ml. 
EXAMPLE 34 
(.mu.-dichloro) (bis-cyclopentadienyl-titanium)-fulvene 
Following the procedure of Example 1, 1.1 g (6.2 mMoles) of anthracene and 
42.7 g of cyclopentadiene are added to 10.94 g (450 mMoles) of fine 
magnesium powder in 300 ml of THF, followed by activation with 0.1 ml of 
methyliodide and by treatment for 3 hours in an ultrasonic bath. 56.9 g 
(33 ml=300 mMoles) of TiCl.sub.4 are then added dropwise, which initiates 
an extremely vigorous reaction and an increase in temperature to 
69.degree. C. After the addition, the mixture is allowed to cool to 
23.degree. C. and 14.8 g of a scarlet-red compound are obtained after 12 
hours, being isolated by filtration. Another 69.1 g are obtained from the 
filtrate by concentration. Total yield: 83.9 g of C.sub.5 H.sub.4 
--C.sub.5 H.sub.4 Ti.sub.2 (C.sub.5 H.sub.5).sub.2 Cl.sub.2 corresponding 
to 179.9 mMoles=66% of the theoretical. 
Elemental analysis: Observed: C: 40.05%; H: 5.75%; Ti: 7.26%; Cl: 32.21%. 
Mass spectrum: m/e: 424 (M+). 
EXAMPLE 35 
Cp.sub.2 TiCl.sub.2 
6 g (24.2 mMoles) of pale red Cp.sub.2 TiCl.sub.2 (corresponding to 48.4% 
of the theoretical) are obtained from a mixture corresponding to Example 
34 containing 1.2 g (50 mMoles) of magnesium powder, 0.2 g (1 mMole) of 
anthracene in 50 ml of THF and also 8.4 g (128 mMoles) of cyclopentadiene 
and 16.7 g (50 mMoles) of TiCl.sub.4.2THF by concentrating the reaction 
mixture by evaporation to dryness, extraction with CH.sub.2 Cl.sub.2 and 
crystallization. 
Elemental analysis: Observed: C: 45.00%; H: 4.19%; Ti: 18.59%; Cl: 32.5%. 
Mass spectrum: m/e: 248 (M.sup.+) 
EXAMPLE 36 
Bis-.eta..sup.5 -methylcyclopentadienyl titanium dichloride 
Following the procedure of Example 1, 0.18 g (1 mMole) of anthracene is 
added to 1.2 g (50 mMoles) of magnesium powder in 50 ml of THF, followed 
by additional activation for 3 hours in an ultrasonic bath. After heating 
to 65.degree. C., 8 g (100 mMoles) of 1-methylcyclopentadiene are added 
and 16.7 g (50 mMoles) of solid titanium-(IV)chloride.2THF are introduced 
over a period of 10 minutes. The reaction mixture changes color via 
grey-brown to scarlet red with vigorous evolution of heat (up to 
70.degree. C.). After cooling to 23.degree. C., the reaction mixture is 
concentrated to dryness in vacuo (10.sup.-2 Torr) and the residue is 
extracted with chloroform, giving 5.92 g (21.46 mMoles=43%) of a 
yellow-red product. 
EXAMPLE 37 
.eta..sup.5 -(.alpha.-methylindenyl)-cobalt cycloocta-(1,5)-diene 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyl iodide 
are added in an inert gas atmosphere to 7.2 g (300 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-green solution is formed while 
stirring at room temperature, orange colored magnesium anthracene 
precipitating therefrom after 1 to 2 hours. The reaction mixture is then 
activated for about 1 hour in an ultrasonic bath and heated while stirring 
to 65.degree. C. After the addition of 27.32 g (253 mMoles) of CO-1,5-D 
and 13.84 g (107 mMoles) of .alpha.-methyl indene, the heat source, is 
removed and 35.61 g (100 mMoles) of cobalt-(III)-acetylacetonate are added 
in portions over a period of 30 minutes, the reaction solution undergoing 
a change in color to black-red with spontaneous heating to the point of 
vigorous refluxing (72.degree. C.). After cooling to room temperature, the 
reaction mixture is stirred overnight (approximately 16 hours), filtered 
off from unreacted magnesium and insoluble fractions through a G-3-glass 
frit and the filtrate concentrated to dryness in a high vacuum (10.sup.-3 
mbar). The black-brown residue is taken up in 400 ml of pentane and 
refiltered through a G-3-glass frit for separation from insoluble 
fractions. The filter cake is washed in portions with a total of 150 ml of 
pentane and the red-brown filtrate is concentrated to 100 ml. The complex 
is then crystallized out by gradual cooling to -80.degree. C. The 
supernatant mother liquor is removed under pressure, washed twice with 50 
ml of pentane cooled to -80.degree. C. and the crystals dried in a high 
vacuum (10.sup.-3 mbar). Yield: 14.3 g=48.3 mMoles=48.3% of .eta..sup.5 
-(.alpha.-methylindenyl) cobalt cycloocta-(1,5)-diene, 
M.p. 72.degree.-73.degree. C. 
Elemental analysis: Calculated: C: 72.97%; H: 7.09%; Co: 19.93%; Observed: 
C: 72.92%; H: 7.14%; Co: 19.98%. 
IR-analysis: 2820-3000; 1468; 1452; 1424; 1370; 1335; 1318; 1205; 845; 810 
cm.sup.-1. 
__________________________________________________________________________ 
.sup.1 HNMR 
(d.sub.8 -toluene) 
__________________________________________________________________________ 
.delta.H.sub.1 
5.59 
ppm (d, J = 2.8 Hz) 
.delta.H.sub.2 
3.82 
ppm (d, J = 2.8 Hz) 
.delta.H.sub.3 .delta.H.sub.4 .delta.H.sub.5 .delta.H.sub.6 .delta.H.sub.7 
4 7.20 1.30 3.21 2.12 1.50 
ppm (m) ppm (s) ppm (m) ppm (m) ppm (m) 
##STR6## 
__________________________________________________________________________ 
.sup.13 CNMR 
(d.sub.8 -toluene) 
__________________________________________________________________________ 
.delta.C.sub.1/4 .delta.C.sub.2 .delta.C.sub.3 .delta.C.sub.4/1 .delta.C.s 
ub.5 69.71 31.87 30.81 67.67 84.97 
ppm ppm ppm ppm ppm 
##STR7## 
.delta.C.sub.6 
89.92 
ppm .delta.C.sub.10/13 
121.06 ppm 
.delta.C.sub.7 
73.86 
ppm .delta.C.sub.11/12 
124.04 ppm 
.delta.C.sub.8 
105.59 
ppm .delta.C.sub.13/10 
123.40 ppm 
.delta.C.sub.9 
105.44 
ppm .delta.C.sub.14 
9.81 ppm 
__________________________________________________________________________ 
Mass spectrum: m/e 296 (100%); 266 (44%); 188 (86%); 129 (42%); 128 (60%); 
113 (38%); 59 (89%). 
EXAMPLE 38 
0.36 g (2.0 mMoles) of anthracene and 0.1 ml of ethylbromide are added to 
2.43 g (0.10 mole) of magnesium powder (50 mesh) in 150 ml of THF and the 
resulting suspension is stirred at room temperature until the 
orange-colored deposit of magnesium anthracene has precipitated 
(approximately 2 hours). 26 ml (0.3 mole) of liquid butadiene are then 
added to the suspension at 0.degree. C., followed by the introduction with 
stirring over a period of 30 minutes of 13.0 g (0.10 mole) of anhydrous 
NiCl.sub.2. After stirring for 20 hours at 0.degree. C., the mixture is 
cooled to -78.degree. C., filtered off from MgCl.sub.2, unreacted 
magnesium and NiCl.sub.2 at that temperature and the filter cake washed 
with cold THF. The deep red colored filtrate contains 82.5% of the nickel 
used in soluble form. A 10 ml sample of the filtrate (275 ml in all) takes 
up 328 ml of H.sub.2 during hydrogenation (25.degree. C./1 bar), metallic 
nickel being quantitatively separated out. The removal of THF and 
distillation in a high vacuum leaves 0.62 g of saturated hydrocarbons 
having the following composition (in % by weight, according to analysis by 
gas chromatography): n-dodecane 76.8, cyclododecane 10.3, n-octane 3.1 and 
n-hexadecane 0.5% (remainder unknown compounds). The quantity of 
n-dodecane corresponds to a yield of the 
.eta..sup.3,.eta..sup.2,.eta..sup.3 -dodeca-2,6,10-triene-1,13-diyl nickel 
(I) (Bogdanovic, Heimbach, Kroner, Wilke, Hoffmann and Brandt, Liebigs 
Ann. Chem. 727, 143 (1969)) of 77% (based on the NiCl.sub.2 used). The 
molar ratio of Ni to n-dodecane amounts to 1.00:0.93 (theoretical 1:1). 
##STR8## 
For comparison, a test was carried out in the same way using the same 
quantities of materials, but no anthracene. In this case, only 37% of the 
nickel used was recovered in solution after filtration at low temperature. 
EXAMPLE 39 
.eta..sup.6 -phenylborinato-cobalt cycloocta-(1,5)-diene 
24 mg (0.13 mMole) of anthracene, 6 ml of THF and 1 drop of methyliodide 
are added in an inert gas atmosphere to 146 mg (6 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-green solution is formed while 
stirring at room temperature, orange-colored magnesium anthracene 
precipitating therefrom in about 1 to 2 hours. The reaction mixture is 
activated for about 3 hours in an ultrasonic bath (Sonorex RK 514, a 
product of the Bandelin company, continuous HF peak output 400 watts, 35 
kHz) and then heated while stirring to 60.degree. C. After the addition of 
550 mg (5.09 mMoles) of cycloocta-(1,5)-diene and 350 mg (2.27 mMoles) of 
1-phenylboracyclohexa-2,5-diene in 4 ml of THF, the heat source is removed 
and 710 mg (1.99 mMoles) of solid cobalt-(III)-acetylacetonate are 
introduced over a period of 3 minutes, the reaction mixture changing color 
to deep orange-brown with spontaneous heating to the point of vigorous 
refluxing (73.degree. C.). After cooling to room temperature, all the 
volatile fractions are distilled off in vacuo (10.sup.-3 mbar), the 
brittle brown residue is taken up on approximately 80 ml of pentane and 
the resulting solution filtered off from insoluble residues through a 
G-3-frit. The complex is crystallized out from the clear orange colored 
filtrate by gradual cooling to -80.degree. C., the supernatant mother 
liquor is separated off and the crystals are dried in vacuo (10.sup.-1 
mbar). Yield: 270 mg=0.84 mMole=42.2% of .eta..sup.6 -phenylborinatocobalt 
cycloocta-(1,5)-diene, M.p. 169.degree. C. (lit.: 169.degree. C.). 
Literature: G. E. Herberich, W. Koch and H. Leuken, J. Organomet. Chem. 
160 (1978) 17-23. 
EXAMPLE 40 
.eta..sup.5 -cyclopentadienyl vanadium 
1.1 g (6.2 mMoles) of anthracene, 300 ml of THF and 0.1 ml of methyliodide 
are added in an inert gas atmosphere to 7.2 g (300 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-green solution is formed with 
stirring at room temperature, orange colored magnesium anthracene 
precipitating therefrom in about 1 to 2 hours. The reaction mixture is 
activated for about 3 hours in an ultrasonic bath (Sonorex RK 514, a 
product of the Bandelin company, continuous HF peak output 400 watts, 35 
kHz) and then heated with stirring to 65.degree. C. After the addition of 
26.4 g (400 mMoles) of monomeric cyclopentadiene, 15.7 g (100 mMoles) of 
solid vanadium-(III)-chloride are introduced over a period of 10 minutes. 
The reaction mixture is then heated for another 4.5 hours to 60.degree. C. 
and, after cooling to room temperature, is filtered off from insoluble 
fractions through a G-3-glass frit. The deep violet filtrate is 
concentrated to dryness in vacuo (10.sup.-1 mbar) and the black-violet 
residue is taken up in approximately 150 ml of pentane. After refiltration 
through a G-3-glass frit for separation from insoluble fractions, the 
clear deep violet filtrate is slowly cooled to -80.degree. C. and the 
complex allowed to crystallize out overnight. The supernatant mother 
liquor is removed under pressure and the crystals are washed twice with 30 
to 40 ml of pentane cooled to -80.degree. C. and dried in vacuo (10.sup.-1 
mbar) at room temperature. 
Yield: 3.4 g=18.8 mMoles=18.8% of bis-.eta..sup.5 -cyclopentadienyl 
vanadium, M.p. 166.degree. C. (lit.: 167.degree.-168.degree. C.). 
Literature: E. O. Fischer, W. Hafner, Z. Naturforsch. 96 (1954) 503-504. 
EXAMPLE 41 
.eta..sup.5 -cyclopentadienyl cobalt cycloocta-(1,5)-diene (two stages) 
1st stage 
1.1 g (6.2 mMoles) of anthracene, 150 ml of THF and 0.1 ml of methyliodide 
are added in an inert gas atmosphere to 7.2 g (300 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-brown solution is formed with 
stirring at room temperature, orange colored magnesium anthracene 
precipitating therefrom in approximately 1 to 2 hours. The reaction 
mixture is cooled to -25.degree. C., followed by the addition of 32.4 g 
(300 mMoles) of cycloocta-(1,5)-diene. 21.9 g (100 mMoles) of solid 
cobalt-(II)-bromide are then introduced over a period of 3 hours 20 
minutes, the reaction mixture changing color from green to dark 
grey-green. After stirring overnight at -30.degree. C. (16 hours), 100 ml 
of toluene cooled to -30.degree. C. are added to the green-black 
heterogeneous reaction mixture which is filtered off from insoluble 
residues at -30.degree. C. through a G-3-glass frit with a cooling jacket. 
The grey-green frit residue is dried for 3 hours in a high vacuum 
(10.sup.-3 mbar) and extracted with 400 ml of toluene heated to 80.degree. 
C., followed by filtration at 80.degree. C. to remove undissolved 
residues. A green-black solid precipitates from the clear dark green 
filtrate by gradual cooling to room temperature. After the supernatant 
mother liquor has been removed under pressure, followed by drying in a 
high vacuum (10.sup.-3 mbar), a black-green solid is obtained in a 
quantity of 2.8 g. 
Elemental analysis: Observed: C: 32.56%; H: 4.80%; Co: 7.26%; Mg: 6.83%; 
Br: 40.37%. 
2nd stage 
700 mg (0.83 mMoles of cobalt) of the green-black solid described above are 
dissolved in 50 ml of THF and 560 mg (3.15 mMoles) of solid 
cyclopentadienyl sodium/dimethoxy ethane adduct added to the resulting 
solution at room temperature. After heating for 6 hours to 60.degree. C., 
a brown solution and a light deposit are formed. The solution is filtered 
off from the deposit through a G-4-glass frit and the brown filtrate is 
concentrated to dryness in a high vacuum (10.sup.-3 mbar). The residue is 
taken up in approximately 100 ml of pentane, the resulting solution 
filtered off from any insoluble residues and the filtrate concentrated to 
approximately 30 ml. After the addition of 20 ml of oxygen-free water, the 
mixture is vigorously stirred for about 1 hour. The orange colored organic 
phase is then isolated and separated up by adsorption chromatography in an 
approximately 30 cm long Al.sub.2 O.sub.3 -column (activity stage II). The 
orange colored main runnings are concentrated to approximately 10 ml and 
the complex is crystallized out by cooling to -80.degree. C. The 
supernatant mother liquor is removed under pressure and the orange colored 
crystals are dried in vacuo (10.sup.-1 mbar). 
Yield: 19 mg=0.082 mMole=9.9% of .eta..sup.5 -cyclopentadienyl cobalt 
cycloocta-(1,5)-diene, M.p. 102.degree. C. (lit.: 103.degree. C.). 
Literature: R. B. King, P. M. Treichel and F. G. A. Stone, J. Am. Chem. 
Soc. 83 (1981) 3593-3597. 
EXAMPLE 42 
.eta..sup.5 -cyclopentadienyl cobalt cycloocta-(1,5)-diene (two stages) 
1st stage 
1.1 g (6.2 mMoles) of anthracene, 150 ml of THF and 0.1 ml of methyliodide 
are added in an inert gas atmosphere to 7.2 g (300 mMoles) of magnesium 
powder (particle size &lt;0.15 mm). A yellow-green solution is formed while 
stirring at room temperature, orange colored magnesium anthracene 
precipitating therefrom in about 1 to 2 hours. The reaction mixture is 
cooled to -25.degree. C., followed by the addition of 32.4 g (300 mMoles) 
of cycloocta-(1,5)-diene. 13.0 g (100 mMoles) of cobalt-(II)-chloride are 
then introduced over a period of 3 hours, the reaction mixture changing 
color from the blue to grey-green. After stirring for 48 hours at 
-30.degree. C., 100 ml of toluene cooled to -30.degree. C. are added to 
the dark grey-green heterogeneous reaction mixture which is then filtered 
off at -30.degree. C. from any insoluble residues through a G-3-glass frit 
with a cooling jacket. The grey-green frit residue is washed twice with 
200 ml of pentane and dried for 3 hours in a high vacuum (10.sup.-3 mbar). 
The grey-green powder is extracted with 500 ml of toluene heated to 
80.degree.-90.degree. C., followed by filtration at 80.degree. C. for 
separation from insoluble residues. A green-black solid is precipitated 
from the clear dark green filtrate by gradual cooling to room temperature. 
After the supernatant mother liquor has been removed under pressure, 
followed by drying in vacuo (10.sup.-3 mbar), a green black, glistening 
solid is obtained in a quantity of 19.5 g. 
Elemental analysis: Observed: C: 54.76%; H: 8.28%; Co: 7.27%; Mg: 5.71%; 
Cl: 13.11%. 
2nd stage 
1.2 g (1.5 mMoles of cobalt) of the green-black solid described above are 
dissolved in 75 ml of THF and 5.2 g (29 mMoles) of solid cyclopentadienyl 
sodium/dimethoxy ethane adduct are added to the resulting solution at room 
temperature. After heating overnight to 70.degree. C. (approximately 16 
hours), a brown solution and a light voluminous deposit are formed. The 
solution is filtered off from the deposit through a G-4-glass frit and the 
brown filtrate is concentrated in a high vacuum (10.sup.-3 mbar). The oily 
residue is taken up in 100 ml of pentane, the solution filtered off from 
any insoluble residues and the clear orange colored filtrate is separated 
up by adsorption chromatography in an approximately 30 cm long Al.sub.2 
O.sub.3 -column (activity stage II). The orange-yellow colored main 
runnings are concentrated to approximately 20 ml and the complexes 
crystallized out by cooling to -80.degree. C. The supernatant mother 
liquor is removed under pressure and the orange-brown crystals are dried 
in vacuo (10.sup.- 1 mbar). Yield: 27 mg=0.12 mMoles=8% of .eta..sup.5 
-cyclopentadienyl cobalt cycloocta-(1,5)-diene, M.p. 
102.degree.-103.degree. C. (lit.: 103.degree. C.). Literature: R. B. King, 
P. M. Treichel and F. G. A. Stone, J. Am. Chem. Soc. 83 (1981) 3593-3597. 
EXAMPLES 43 TO 46 
The use of magnesium activated by substituted anthracenes is illustrated by 
4 examples for the production of .eta..sup.5 -indenyl cobalt 
cycloocta-(1,5)diene. 
EXAMPLE 43 
The procedure of example 11 is followed except that 6 mMoles 
2-methylanthracene is used in place of anthracene. 
Yield: 20.3 g (20.3 mMoles=72%). 
EXAMPLE 44 
The procedure of example 11 is followed except that 6 mMoles 
9-methylanthracene is used in place of anthracene. 
Yield: 18.3 g (18.3 mMoles=65%). 
EXAMPLE 45 
The procedure of example 11 is followed except that 6 mMoles 
1,4-dimethylanthracene is used in place of anthracene. 
Yield: 18.9 g (18.9 mMoles=67%). 
EXAMPLE 46 
The procedure of example 11 is followed except that 6 mMoles 
9,10-diphenylanthracene is used in place of anthracene. 
Yield: 16.1 g (16.1 mMoles=57%).