VAPOR-PRESSURES AND ENTHALPIES OF SUBLIMATION OF POLYCYCLIC AROMATIC-HYDROCARBONS AND THEIR DERIVATIVES

The vapor pressures of a series of polycyclic aromatic hydro carbons ( PAH) and heteroatom-containing PAH have been measured using the Knudse n effusion technique. Aromatic hydrocarbons examined included anthrace ne, phenanthrene, pyrene, 2,3-benzofluorene, naphthacene, perylene, pe ntacene, and coronene. Heteroatomic aromatic species examined included phenanthridine, perinaphthenone, 3-hydroxy-1-phenalen-1-one, benz[g]i soquinoline-5,10-dione, 1,2-benzodiphenylene sulfide, 1-hydroxypyrene, and 6,11-dihydroxy-5,12-naphthacenedione. The measurements were all m ade in the solid sublimation regime, and enthalpies of sublimation wer e calculated from the Clausius-Clapeyron equation.