Hydrogenation of Pyrene and Catalytic Interconversion of Hydropyrenes

Article abstract of DOI:10.1246/bcsj.58.1962

Reexamination on the hydrogenation of pyrene (1) with Raney nickel catalyst under atmospheric pressure afforded a mixture of 4,5-di- (2), 4,5,9,10-tetra- (3), 1,2,3,6,7,8-hexa- (4), and 1,2,3,3a,4,5-hexahydropyrene (5).The relative amount of each product at the initial reaction stage was determined by time-yield relation of the products.The formation sequence of the products is discussed with reference to the hydrogenations of 2-5: 4 may be formed independent of 2, and 2 is converted to 3.Hydropyrene 5 may be produced from 1 mainly through the same ?-adsorbed species which also leads to 2.The hydrogenation of 1 with palladium and platinum catalysts gave similar results as with nickel.With nickel and palladium catalysts the hydrogenation of 1 was faster than that of 4H-cyclopentaphenanthrene (9).However, with platinum the hydrogenation of 1 was slower than that of 9.Catalytic interconversion of 2-5 was examined at 240 deg C under an argon pressure of 90 kg cm^-2.Hydroarene 2 was easily dehydrogenated, and 3 and 5 were interconverted to a fair extent.Therefore, 2,3, and 5 may be good hydrogen donor solvents for coal liquefaction.