SPECTROSCOPIC STUDIES OF PHTHALOCYANINE MONOLAYERS

We have deposited multilayer films of copper tetrakis(cumylphenoxy)phthalocyanine in a 1:1 mixture with octadecanol from a Langmuir monolayer. Using reflection spectroscopy from the monolayer at the gas-water interface, we observe that the phthalocyanine molecules stack into multimeric structures as the monolayer is spread on the water surface and upon compression aggregate further. The monolayer cannot be expanded after compression, possibly because of the slow kinetics of dissociation of the aggregates, the formation of which is a highly favorable process. The compressed monolayer can be transferred to a solid support to form multilayer films in which the phthalocyanine rings are oriented out of the plane of the substrate. Such orientational order increases with number of layers.