Functional metallomacrocycle derivatives and their polymers. Part 23. Biaxially orientated Langmuir–Blodgett films of substituted metallophthalocyanines

Soluble metallophthalocyanine compounds (M = NiII or CuII) with alkyloxycarbonyl groups substituted at either the 2 or 3 position of the benzene ring (alkyl = 1- or 2-octyl, or 1-decyl) were synthesized by the reaction of the corresponding metallophthalocyaninetetracarboxyl chlorides with the alkyl alcohols, and monolayers were formed at a water–air interface. All compounds formed stable monolayers at surface pressures higher than ca. 15 mNm–1. In the Langmuir–Blodgett films built up from monolayers of the compounds on Pyrex substrates, the orientation of the phthalocyanine rings was shown to be biaxial from the one-dimensional orientation of the phthalocyanine stacked columns, observed by measurement of polarized visible absorption spectra.