9,10-Dihydroanthracene

9,10-Dihydroanthracene is an organic compound that is derived from the polycyclic aromatic hydrocarbon anthracene. Several isomers of dihydroanthracene are known, but the 9,10 derivative is most common. It is a colourless solid that is used as a carrier of H2 as a hydrogen-donor.

Preparation
Because the aromaticity is not compromised for the flanking rings, anthracene is susceptible to hydrogenation at the 9- and 10- positions. It is produced in the laboratory by dissolving metal reduction using sodium/ethanol, an application of the Bouveault–Blanc reduction. The reduction can be effected by magnesium as well. Finally, it can also be prepared by the coupling of benzyl chloride using aluminium chloride as a catalyst.

The bond dissociation energy for the 9- and 10- carbon–hydrogen bonds are estimated at 78 kcal mol&minus;1. Thus these bonds are about 20% weaker than typical C–H bonds.