Process for preparing finely divided highly reactive magnesium and use thereof

Claim 1

A process for preparing a highly reactive finely divided magnesium comprising thermally decomposing a magnesium-containing compound selected from the group consisting of (i) a magnesium anthracene and/or its derivatives prepared from magnesium and anthracene and/or its alkyl or phenyl derivatives, (ii) a magnesium butadiene and/or its alkyl or phenyl derivatives prepared from magnesium and a conjugated diene having the general formula R 1 -CH=CR 2 -CH=CH-R 3 , wherein R 1 , R 2 and R 3 are the same or different and represent H, a linear or branched alkyl group having from 1 to 6 carbon atoms or a phenyl residue, and (iii) a magnesium hydride-prepared from magnesium and hydrogen either in the presence of homogenous catalysts comprising a halide of a metal of the Subgroups IV to VII of the Periodic System and an organomagnesium compound or a magnesium hydride and in the presence of a polycyclic aromatic or a tertiary amine, after hydrogenating magnesium with magnesium anthracene or magnesium diene, said thermal decomposition taking place at a pressure from 10 -6 to 1 bar and in the absence or presence of an organic apretic solvent, either the decomposition being carried out in the presence of a co-reactant being added only after completion of the precipitation of the highly reactive magnesium, or in the absence of such co-reactant, the magnesium obtained by said decomposition being isolated as a highly reactive powder.