The synthesis and study of some novel amphiphilic phthalocyanines.
The syntheses of phthalocyanines and particularly substituted
phthalocyanines, together with some of their main applications, are described.
Asymmetrically octasubstituted phthalocyanines, where the substituents on
one benzene ring differ from the substituents on the other three rings are most
commonly obtained from statistical mixtures of precursors derived from
phthalic acid. The synthesis of a series of such compounds together with their
substituted phthalonitrile precursors containing both hydrophilic and
hydrophobic side-chain substituents is discussed. This novel series of nonperipherally
substituted amphiphilic phthalocyanines were shown to possess
liquid crystalline properties. The various liquid crystal discotic mesophases
were characterised. As a consequence of their hydrophilic-hydrophobic
balance and high solubility in organic solvents, the compounds were studied
as Langmuir-Blodgett films. The synthesis and Langmuir monolayer
behaviour of peripherally octa-t-butylphthalocyanine is also described. The
latter part of this thesis includes a discussion of the mechanisms of the
synthesis of phthalocyanines from various precursors and particularly from
phthalonitrile, which complements the synthetic aspects of the work. The
thesis concludes with an investigation into the feasibility of a stepwise
conversion of phthalonitrile precursors into the macrocycle for the preparation
of asymmetrically substituted phthalocyanines.