Abstract Treatment of phenanthrene-9, 10-dione (PQ) with phenanthrene-9, 10-diol (PQH 2), as prepared by catalytic hydrogenation of PQ, in toluene solution or in the solid state afforded crystalline '9, 10-phenanthrenequinhydrone'(PQH), the first example of an ortho- quinhydrone. PQH was characterized by analytical and spectroscopic methods, including X- ray and CP/MAS 13 C-NMR analyses. The crystal structure of PQH showed pairs of planar ...
