This paper presents experimental results on the phase behavior of the
binary system propane + triphenylmethane. Besides vapor-liquid equilib
ria, also equilibria in the presence of solid triphenylmethane have be
en determined experimentally. Special attention was given to determine
the course of the various three-phase equilibria originating in the q
uadruple point solid triphenylmethane-liquid-liquid-vapor (s(B)l(1)l(2
)g). The experimental work was performed in the temperature region 310
< T/K < 450, while pressures up to 11 MPa have been applied. Surprisi
ngly, it was found that in this binary system the three-phase equilibr
ium liquid-liquid-vapor (l(1)l(2)g) could be determined at supercooled
conditions over a temperature range of about 25 K, i.e. some parts of
the fluid phase behavior could be observed and measured at metastable
conditions.