Synthesis and spectroscopic properties of the first phthalocyanine–nucleobase conjugates

The adenine-containing zinc(II) phthalocyanines 3, 4a, and 4b have been prepared by standard O-alkylation of the tetrahydroxy analogue 1. These macrocycles exhibit rather strong intermolecular interactions resulting in a poor solubility in organic solvents and unusual spectral properties that are highly solvent-dependent. Self-assembly of the tetra-adenine phthalocyanine 3 and the thymine-containing 9,10-anthraquinone 6 through the Watson–Crick base-pairing interactions has also been demonstrated by fluorescence quenching experiments.