MONOLAYER BEHAVIOR AND LANGMUIR-BLODGETT-FILM PROPERTIES OF SOME AMPHIPHILIC PHTHALOCYANINES - FACTORS INFLUENCING MOLECULAR-ORGANIZATION WITHIN THE FILM ASSEMBLY

The monolayer and LB film-forming properties of 20 structurally relate d amphiphilic octa-substituted phthalocyanine derivatives have been as sessed. The molecular packing within examples of the films has been pr obed by visible-region spectroscopy and low-angle X-ray diffraction me thods. Among derivatives where the aliphatic substituents are attached by ether linkages, there is a variation in the behaviour according to the length of the chains and whether or not the chains are branched. Films are not highly ordered but may contain domains of ordered struct ure, giving rise to a red-shifted absorption band in the visible spect rum, Analogues where the chains are attached by carbon-carbon bonds sh ow superior monolayer behaviour and are excellent materials for deposi tion as LB films. Furthermore, there is good evidence from the spectra that change in the length of the alkyl chains provides a means of con trolling the type of molecular packing within the films.