Synthesis and characterisation of some 1,4,8,11,15,18,22,25-octa(alkoxymethyl)phthalocyanines; a new series of discotic liquid crystals

Abstract

A series of 3, 6-bis(alkoxymethyl)phthalonitriles, prepared via Diels–Alder reactions of 2, 5-bis(alkoxymethyl)furans with fumaronitrile, have been converted into the corresponding phthalocyanines. Zn(II) and Cu(II) derivatives of 1,4,8,11,15,18,22,25-octa(heptyloxymethyl)phthalocyanine were also prepared. Examples of the macrocycles were characterised using ¹H NMR spectrometry and optical spectroscopy. Those bearing straight chains aggregate in solutions of chloroform and toluene. The octa(butoxymethyl)phthalocyanine and its longer chain homologues exhibit a discotic liquid crystallinephase. Compounds containing branched sidechains are liquid crystals at room temperature.