title: Polymorphism in benzene, naphthalene, and anthracene at high pressure.
abstract: Optical observations, in which a microscope was used with the diamond-anvil pressure cell, were carried out on benzene, naphthalene, and anthracene up to temperatures of about 600 degrees C and pressures of approximately 40 kilobars. New high-pressure phases of benzene (benzene III) and anthracene (anthracene II) were observed, and the existence of the high-pressure polymorph, naphthalene II, was verified. All three materials decompose initially to a reddish-orange liquid, and ultimately to amorphous carbon. The decomposition temperatures decrease with increasing molecular size.
authors.forename: S
authors.initials: S
authors.lastname: Block
authors.forename: C E
authors.initials: CE
authors.lastname: Weir
authors.forename: G J
authors.initials: GJ
authors.lastname: Piermarini