IMPROVEMENTS OF THE SPREADING CHARACTERISTICS OF MONOLAYERS OF DIDODECYLDIMETHYLAMMONIUM-NI(DMIT)(2), DIDODECYLDIMETHYLAMMONIUM-NI(MNT)(2) AND N-OCTADECYLPYRIDINIUM-NI(DMIT)(2) AT THE AIR WATER INTERFACE/

The addition of 2.5 x 10(-3)% of n-pentanol, or n-hexanol, to chlorofo rm used as the spreading solvent for monolayers of didodecyldimethylam monium-Ni(dmit)(2), and didodecyldimethylammonium-Ni(mnt)(2) (where dm it = 4,5-dimercapto-1,3-dithiole-2-thionato, and mnt = 1,2-dicyano-1,2 -ethenedithiolato) is shown to improve the spreading of the monolayer before compression. Monolayers spread for 5, 15, 30 and 45 minutes are considered. The addition of pentanol to the spreading solution is see n to reduce, or eliminate, plateau regions in the pressure-area isothe rms, which suggests collapse or significant reorientation of the molec ules within the monolayer, in much shorter spreading times. The effect of pentanol on the spreading of N-octadecyl-pyridinium-Ni(dmit)(2) is less apparent, but monolayers of this complex are found to be much ea sier to spread using chloroform only as the spreading solvent, than th e didodecyldimethylammonium complexes.