Vapor pressure studies of pyridine,picolines and 2,6-lutidine in isooctane

The vapor pressures of pyridine, 2-, 3- and 4-picoline and 2,6-lutidine have been determined as a function of their concentration in isooctane at 25°C by gas chromatographic analysis of the head-space over their solutions. Henry's law constants were determined and the vapor pressure data were treated in terms of various self-association models. The apparent self-association of the pyridine bases can be rationalized as resulting from intermolecular interactions with both the nitrogen lone pair of electrons and with the -electrons.