Article,
Heats of Sublimation of Polycyclic Aromatic Hydrocarbons and Their Molecular Packings
Bulletin of the Chemical Society of Japan, (1967)
DOI: 10.1246/bcsj.40.2267
Abstract
The vapour pressure of some polycyclic aromatic hydrocarbons was measured
by means of the effusion method. From the temperature dependence
of the pressure, the heat of sublimation (delta H kcal/mol) and the
entropy (deltaS� cal/mol�deg) were calculated for the following hydrocarbons:
1,2-benzanthracene (deltaH=22.8; deltaS�=44.8), tetracene (29.8;
43.3), chrysene (28.1; 43.0), triphenylene (25.6; 33.9), 3,4-benzophenanthrene
(25.4; �) p-terphenyl (28.3; 47.9), 1,12-benzperylene (30.0; 40.7),
3,4-benztetraphene (32.6; 45.9), 1,2,5,6-dibenzanthracene (33.9;
49.3), pentacene (37.7; 48.9), picene (33.5; 45.9), coronene (30.7;
36.9), 1,2,4,5-dibenzpyrene (32.9; 48.3), 1,2,6,7-dibenzpyrene (35.1;
45.6), 1,3,5-triphenylbenzene (34.0; 55.6), tetrabenzonaphthalene
(33.9; 47.4), isoviolanthrene A (52.2; 54.6), violanthrene A (46.8;
48.1), violanthrene B (36.7; 38.0) and tetrabenzoperylene (28.2;
44.7). The small values of deltaH for violanthrene B, tetrabenzoperylene
and tetrabenzonaphthalene may reflect the existence of the non-coplanar
structure of their molecules. Further, the large values of deltaS�
for triphenylbenzene and terphenyl suggested the possibility of the
rotation about their single bonds.
