DE1206897B - Process for the production of dicyclopentadienyls of cobalt and nickel - Google Patents

Description

Process for the production of dicyclopentadienyls of cobalt and Nickels It is known that one can use cyclopentadienyl compounds of iron or manganese can be prepared in such a way that the halides of the metals mentioned, in particular the chlorides, with alkali or alkaline earth compounds of cyclopentadiene or its Implements derivatives.

For a number of metals, e.g. B. with cobalt and nickel, it was however, their halides have so far not been possible or only possible with a very poor yield with alkali or alkaline earth compounds of cyclopentadiene or its derivatives to react.

It has now been found that dicyclopentadienyls of cobalt and Nickel from the corresponding alkali or alkaline earth metal cyclopentadienyls and the anhydrous halides of cobalt or nickel in organic solvents Can be used if the reaction is carried out at temperatures above 0 ° C in the presence carried out by ammonia.

As cyclopentadienyl alkali compounds according to the invention for the Implementation with anhydrous halides are suitable, for. B.

Cyclopentadienyl sodium, cyclopentadienyl potassium, cyclopentadienyl lithium, Alkylcyclopentadienyl sodium, such as methyl or ethylcyclopentadienyl sodium and Indenyl sodium.

As cyclopentadienyl alkaline earth compounds, z. B. dicyclopentadienyl calcium and dicyclopentadienyl magnesium.

Of the halides of cobalt and nickel, the main ones have become the chlorides proved to be particularly reactive.

As an organic solvent in which the implementation of cyclopentadienyl alkali compounds to be carried out with the halides of cobalt and nickel are suitable especially polar solvents such as alcohols, e.g. B. isobutanol, straight-chain Ethers, such as glycol ethers, or cyclic ethers, such as tetrahydrofuran or dioxane.

The reaction according to the invention is carried out at temperatures which are between 0 ° C and the boiling point of the solvent used. ; Normal pressure or higher pressures can be used as pressures.

Although it is already known to use cyclopentadienyl sodium with anhydrous Nickel chloride in the presence of pyridine or ammonia at low temperatures (-40 " C) to implement Niccelocen. With the known methods, however, only low Yields obtained. Only through the use of ammonia at temperatures above 0 ° C, which is technically considerably simpler and cheaper, it was possible to produce dicyclo- pentadienyls of cobalt and nickel in high yields.

Example 1 12 g of sodium wire are in the absence of air and Moisture in 400 ml of tetrahydrofuran with 65 ml of freshly obtained monomeric cyclopentadiene brought to reaction. The solution - also with the exclusion of air and moisture - then a moderate stream of gaseous ammonia for 1 hour directed. Then 35 g of anhydrous nickel chloride are introduced, and the reaction mixture is heated for 2 hours until the solvent boils.

After the mixture has cooled, the solvent is distilled off and the remaining residue is heated in a sublimation apparatus in vacuo. At about 100 "C, 31 g of dicyclopentadienyl nickel of a deep green color sublime The amount obtained corresponds to a yield of 62 percent by weight of theory.

Example 2 As in Example 1 from 12 g of sodium in 400 ml of tetrahydrofuran Cyclopentadienylnati ium obtained was admixed with 35 g of anhydrous nickel chloride.

The mixture was heated to 500 ° C. in a moderate flow for 1 hour gaseous ammonia passed. Then another 1 hour until the solvent boiled warmed up.

Work-up was carried out as in Example 1. 39 g of dicyclopentadienylnickel were obtained obtain; this corresponds - based on the cyclopentadienyl sodium used - a yield of 83,010 of theory.

In a parallel experiment without the use of ammonia could not once traces of dicyclopentadienylnickel are found.

Example 3 12 g of sodium were added to 400 ml of tetrahydrofuran with methylcyclopentadiene implemented. The reaction solution was then mixed with 35 g of anhydrous nickel chloride added and treated with gaseous ammonia for 1 hour. After the mixture is still After heating for 2 hours until the solvent boiled, the tetrahydrofuran became distilled off at normal pressure. Then a deep green liquid went in the vacuum that froze after standing in the refrigerator for a long time. That way were 47 g of dimethylcyclopentadienyl nickel with a melting point of 35 to 370 ° C. were obtained.

That corresponds to a yield of 87 ob, the theory.

Example 4 As in Example 1, 12 g of sodium were dissolved in 400 ml of tetrahydrofuran reacted with cyclopentadiene. After adding 35 g of anhydrous cobalt (II) chloride became 1 hour passed gaseous ammonia through the reaction mixture and then heated for another 2 hours until the solvent boils.

There were 41 g of dicyclopentadienylcobalt in the form of violet-black Crystals with a melting point of 171 to 173 "C were obtained.

This corresponds to a yield of 8701o of theory.

Claims (1)

Claim: Process for the production of dicyclopentadienylene of cobalt and nickel from the corresponding alkali or alkaline earth cyclopentadienyls and the anhydrous halides of cobalt or nickel in organic solvents, characterized in that the reaction is carried out at temperatures above 0 ° C. in Performs presence of ammonia. References considered: U.S. Patent No. 2,920 090.