Magnesium anthracene
Magnesium anthracene is an organomagnesium compound that is almost invariably isolated as its adduct with three tetrahydrofuran ligands. With the formula Mg3, this air- and water-sensitive orange solid is obtained by heating a suspension of magnesium in a thf solution of anthracene.According to X-ray crystallography, the Mg center is 5-coordinate, occupying a C2O3 ligand sphere. The fold angle between the two benzo groups is 72.6°.
The compound behaves as a source of the carbanion 2- as well as a source of highly reactive Mg. With electrophiles, the compound reacts to give dihydroanthracene derivatives C14H10E2. Electrophiles include ketones, CO2, organotin chlorides, and organoaluminium chlorides. Ethylene inserts into one Mg-C bond. Hydrogen induces release of anthracene, yielding magnesium hydride.
